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Unbound issue 2Does not circulate Special Report 988

June 1998

Malheur Experiment StationAnnual Report, 1997

For additional copies of this publication, write

Clint Shock, SuperintendentMalheur Experiment Station595 Onion AvenueOntario, OR 97914

Agricultural Experiment StationOregon State University

Special Report 988June 1998

Malheur Experiment StationAnnual Report, 1997

MALHEUR EXPERIMENT STATIONSPECIAL REPORT - 1997 RESEARCH

TABLE OF CONTENTS

WEATHER1997 WEATHER REPORT 1

ALFALFA FINAL YEAR RESULTS OF THE 1992 TO 1997 ALFALFA VARIETY TRIAL 7SECOND PRODUCTION YEAR OF THE ALFALFA FORAGE VARIETY TRIAL,

1996-2000 11USING DEGREE DAY ACCUMULATIONS TO PREDICT LYGUS HATCHES IN

ALFALFA SEED 13CORN, SWEET CORN, AND NITROGEN MINERALIZATION

EVALUATIONS OF SUPERSWEET CORN AND SWEET CORN VARIETIES 18NITROGEN VALUE OF POTATO AND ONION SLUDGE FOR CORN PRODUCTION 23NITROGEN MINERALIZATION FROM POTATO SLUDGE AND ONION SLUDGE 29PREPLANT INCORPORATED HERBICIDES FOR WEED CONTROL IN FIELD CORN 32

ONIONS

ONION VARIETY TRIAL, GRADED OUT OF STORAGE JANUARY 1998 34EVALUATION OF ONION HARVESTING METHODS 1997 40IRRIGATION MANAGEMENT FOR DRIP-IRRIGATED ONIONS 44POSTEMERGENCE WEED CONTROL IN ONIONS 51THRIPS IDENTIFICATION AND THRIPS CONTROL IN ONIONS 53STRAW MULCH INCREASES YIELD AND GRADE OF FURROW IRRIGATED ONIONS 61

POPLARS AND ALTERNATE CROPSIRRIGATION MANAGEMENT FOR HYBRID POPLAR PRODUCTION 64GROUNDCOVERS FOR HYBRID POPLAR ESTABLISHMENT 72WEED CONTROL FOR POPLAR TREE ESTABLISHMENT 78SOYBEAN RESEARCH AT ONTARIO IN 1997 80'HICKSII' YEWS AS A SUSTAINABLE SOURCE OF ANTICANCER COMPOUNDS 84ASPARAGUS VARIETY PERFORMANCE 89

POTATOES

VALIDATION AND ADAPTATION OF THE "BLITECAST" MODEL FOR PREDICTINGDEVELOPMENT OF POTATO LATE BLIGHT IN OREGON 92

UMATILLA RUSSET POTATOES COMPARED WITH RUSSET BURBANK ANDSHEPODY, 1997 98

PREEMERGENCE HERBICIDES FOR WEED CONTROL IN POTATOES 101POTATO VARIETY TRIALS AT ONTARIO, 1997 108

SUGAR BEETSSUGAR BEET VARIETY TRIAL RESULTS FOR 1997 116

TRANSGENIC SUGAR BEET VARIETY TESTING RESULTS 120

POSTEMERGENCE WEED CONTROL IN SUGAR BEETS 123

"ON FARM" IMPLEMENTATION OF LOWER NITROGEN FERTILIZER INPUTSTHROUGH NITROGEN ACCOUNTING AND VALIDATION OF ORGANIC MATTERMINERALIZATION 126

WHEAT AND SMALL GRAINS1997 SMALL GRAIN VARIETY TRIALS 135IMPROVED NITROGEN AND IRRIGATION EFFICIENCY FOR WHEAT PRODUCTION 143

COMMON AND SCIENTIFIC NAMESHERBICIDES AND ADJUVANTS 149INSECTICIDES, FUNGICIDES, AND NEMATICIDES 150CROPS & WEEDS 151

CONTRIBUTORS AND COOPERATORSMALHEUR EXPERIMENT STATION SPECIAL REPORT

1997 RESEARCH

MALHEUR COUNTY OFFICE, OSU EXTENSION SERVICE PERSONNEL:

Jensen, Lynn ProfessorMoore, Marilyn InstructorSimko, Ben ProfessorKnutson, Devon Assistant Professor

MALHEUR EXPERIMENT STATION:

Eldredge, EricFelber( ErikGuza, CoreyIshida, JoeyJones, JanetRansom, CoreySaunders, LamontShock, Clinton C.

Research AssistantResearch AssistantGraduate Research AssistantBio Science Research TechnicianOffice CoordinatorAssistant Professor of Weed ScienceBio Science Research TechnicianProfessor, Superintendent

MALHEUR EXPERIMENT STATION, STUDENTS:

Brad CoenFrisch, DeanaHeck, AbbeyKimberling, KatieKirk, AmandaTrenkel, Jan

Research AideResearch AideApprentice in Science and EngineeringApprentice in Science and EngineeringApprentice in Science and EngineeringResearch Aide

OREGON STATE UNIVERSITY, CORVALLIS, AND OTHER STATIONS:

Appleby, ArnoldBaggett, JamesBurrill, LarryEnglish, MarshallHane, DanJames, StevenKarow, RussellKogan, MarcosKronstad, WarrenMansour, BillMosley, AlvinPowelson, Mary L.

Professor Emeritus, Dept. of Crop and Soil ScienceProfessor, Dept. of HorticultureProfessor Emeritus, Dept. of Crop and Soil ScienceProfessor, Dept. Bioresource EngineeringInstructor, HermistonSenior Research Assistant, MadrasProfessor, Dept. of Crop and Soil ScienceProfessor, Director, Integrated Plant Protection CenterProfessor, Dept. of Crop and Soil ScienceProfessor, Dept. of HorticultureAssociate Professor, Dept. of Crop and Soil ScienceProfessor, Dept. Botany & Plant Pathology

Richardson, Daryl Professor, Dept. of HorticultureRykbost, Ken Professor, Superintendent, Klamath Falls

UNIVERSITY OF PORTLAND:

Hoffman, Angela Professor

UNIVERSITY OF IDAHO AND ARS:

Brown, BradfordLove, SteveMohan, KrishnaPavek, JoeWestermann, Dale

Associate Professor, Parma, IDAssociate Professor, Aberdeen, IDProfessor, Parma, IDResearch Geneticist/Potato Breeder USDA, Aberdeen, IDProfessor, USDA, Kimberly, ID

OTHER PERSONNEL COOPERATING ON SPECIAL PROJECTS:

Amoth, DaveBeck, MikeBowers, DonCamp, StaceyCapps, GreggCooper, R. L.Corbett, JimEllison, DaveFukiage Bros.Gheen, EdHawkins, AlHobson, JoeHunter, BruceHuffacker, Boblida, SteveJohnson, AngieJones, RonKomoto, BobLee, GordonLund, SteveMcCordy, PatMickelsen, MikeMillard, ClarkMiller, TerryNakada, VernonOftedal, StevePogue, BillPtacek, LannySaito, ReidSeward, Leroy

Northwwest Essential OilsCooperating Farmer, Burley, IDAmalgamated Sugar, Nyssa, ORAmalgamated Sugar, Rupert, IDDistrict Liason/Waterquality Specialist NRCS, Ontario, ORARS, Wooster, OHCarnation Co., Nampa, IDAmalgamated Sugar Co., Burley, IDCooperating Farmers, Vale, ORWatershed Coordinator SWCD, Ontario, ORlrrometer Co., Riverside, CAHobson Manufacturing, Ontario, ORCooperating Farmer, Ontario, ORAmalgamated Sugar, Nyssa, ORCooperating Farmer, Ontario, ORBeef Northwest, Nyssa, ORDistrict Manager SWCD, Ontario, OROntario Produce, Ontario, ORCooperating Farmer, Ontario, ORAmalgamated Sugar Co., Twin Falls, IDCooperating Farmer, Brogan, ORCooperating Farmer, Minidoka, IDAmalgamated Sugar Co., Paul, IDMiller Research, Minidoka, IDCooperating Farmer, Ontario, ORCal-West Seeds, Ontario, ORIrrometer Co., Inc. Riverside, CANelson Irrigation, Walla Walla, WACooperating Farmer, Nyssa, ORCooperating Farmer, Anderson Corner, ID

Schneider, GarySimantel, GeraldStander, J. R.Stubstad, JohnTeramura, KenTraveler, DelUstick, RichardVogt, GlennWalhert, BillWearsler, KenWettstein, LouWillison, Greg

Beef Northwest, Nyssa, ORNovartis Seed, Longmont, COBetaseed, Inc., Kimberly, IDAndrews Seed, Ontario, ORCooperating Farmer, Ontario, ORAmalgamated Sugar, Burley, IDCooperating Farmer, Minidoka, IDJ.R. Simplot Co., Caldwell, IDAmalgamated Sugar, Ontario, ORPopular Intensive Culture Technology Inc.Cooperating Farmer, Ontario, ORAmerican Fine Foods, New Plymouth, ID

GROWERS ASSOCIATIONS SUPPORTING RESEARCH:

Idaho Alfalfa Seed Growers AssociationIdaho-Eastern Oregon Onion CommitteeMalheur County Potato GrowersNevada Seed CouncilNyssa-Nampa Beet Growers AssociationOregon Alfalfa Seed CommissionOregon Alfalfa Seed Growers AssociationOregon Potato CommissionOregon Processed Vegetable CommissionOregon Wheat CommissionWashington Alfalfa Seed Growers

OREGON PUBLIC AGENCIES SUPPORTING RESEARCH:

Department of AgricultureDepartment of Environmental QualityDepartment of Economic Development

1997 WEATHER REPORT

Erik B. G. Feibert and Clint C. ShockMalheur Experiment Station

Oregon State, UniversityOntario, Oregon

Introduction And Methods

Daily observations of air temperature and precipitation have been recorded at theMalheur Experiment Station since July 20, 1942. Installation of additional equipment in1948 allowed for evaporation and wind measurements. Evaporation is measured asinches of water evaporated from a standard 10-inch deep by 47.5-inch diameter panover 24 hours. Wind run is measured as total wind movement in miles over a 24 hourperiod measured at 24 inches above ground level. A soil thermometer at 4-inch depthwas added in 1967. A biophenometer, to monitor degree days, and pyranometers, tomonitor solar and photosynthetically active radiation, were added in 1985.

Since 1962, daily readings from the station have been reported to the U.S. Departmentof Commerce, Environmental Science Service Administration, and the NationalWeather Service. Each day the 8 AM air temperature, preceding 24-hour air and soiltemperature extremes, and 24-hour accumulated precipitation are recorded and weretransmitted to radio station KSRV in Ontario. KSRV then conveyed this information,along with their own daily readings, to the U.S. Weather Station in Boise, Idaho. Duringthe irrigation season (April -October), evaporation, wind, and water temperature arealso monitored and reported.

On June 1, 1992, in cooperation with the U.S. Bureau of Reclamation, a fully automatedweather station, connected by satellite to the Northwest Cooperative AgriculturalWeather Network (AgriMet) computer in Boise, Idaho, began transmitting data fromMalheur Experiment Station. The automated station monitors air temperature, relativehumidity, dew point temperature, precipitation, wind run, wind speed, wind direction,solar radiation, and soil temperature at 8-inch and 20-inch depths. Stored data istransmitted via satellite to the Boise computer every 4 hours and is used to calculatedaily Malheur County crop water-use estimates. The database may be accessed viacomputer modem or through the Internet (http://www.pn.usbrgov/agrimet).

In July 1997, the daily weather data started being reported directly to the NationalWeather Service computer via phone. In June 1997, the daily weather data and themonthly weather summaries started being posted on the Malheur Experiment Stationweb site on the Internet (http://www.primenet.com/mesosu). On October 17, 1997, sodwas layed around and under the weather stations. The sod will be irrigated with

subsurface drip irrigation. The ground around and under the weather stations prior toOctober 17, 1997, was bare.

The most unusual weather events in 1997 were a tornado and a microburst. Thetornado occurred on April 30 at approximately 11 AM and went through the station, butdid not hit any buildings on the station. A minisprinkler system with risers attached tometal stakes that was being used to germinate an onion field was torn apart. Some ofthe risers with metal stakes were thrown into an adjacent field about 150 feet away.The tornado then proceeded into Ontario causing damage to some buildings. Themicroburst occurred on June 17 near Nyssa and Adrian, Oregon and caused extensivecrop damage.

The weather in 1996 did not exceed any record weather events recorded over the54-year history for the Malheur Experiment Station (Table 1). Total precipitation was9.45 inches for the year, close to the 10-year and 54-year station averages (Table 2).Total snowfall for 1996 was 5.8 inches, 29 and 30 percent below the 10-year and54-year means, respectively (Table 3).

Mean monthly maximum air temperatures were close to the 10-year and 54-year means(Table 4). The monthly total accumulated growing degree days (50-86 °F) was slightlyhigher than the 10-year mean (Table 5, Figure 1). The monthly total number of degreedays in the 86-104 °F range was close to the 8-year average (Table 6). The meanmonthly maximum and minimum 4-inch soil temperatures were close to the 10- yearand 54-year means (Table 7).

Total pan-evaporation for April through October was 59.8 inches, close to the 10-yearmean and above the 48-year mean (Table 8).

The last spring frost (<32 °F) occurred on May 3, seven days later than the 20-yearmean date of April 26; the first fall frost occurred on October 8, four days later thannormal (Table 9).The monthly wind-run totals for the months of April through October were higher thanthe 49-year mean (Table 10).

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Table 1. Record weather events at the Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon.

Record event Measurement Date Greatest annual precipitation 16.87 in 1,983Greatest 24-hour precipitation 1.52 in Sep 14, 1959

Greatest annual snowfall 40 in 1,955Greatest 24-hour snowfall 10 in Nov 30, 1975

Earliest snowfall 1 in Oct 25, 1970Highest air temperature 108 °F Aug 4, 1961

Table 2. Annual precipitation. Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1986-1997.

10-yr 54-yr1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 mean mean

inches

8.64 9.81 7.58 9.15 7.21 9.25 8.64 13.3 10.05 14.01 12.69 9.45 9.76 10.24

Table 3. Annual snowfall totals at the Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1986-1997.

10-yr 54-yr1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 mean mean

inches

13 15.5 34.8 25.1 5.7 7.5 15.5 36 32 15 14.5 5.8 20.01 19.62

Table 4. Monthly air temperature. Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily

High Low High Low High Low High Low High Low High Low High Low High Low High Low High Low High Low High Low

°F

Max. 58 41 56 32 79 45 76 48 92 59 90 57 102 65 101 59 94 60 94 45 64 39 48 33

Min. 27 6 32 19 45 22 50 19 58 26 71 42 72 44 84 46 67 35 50 21 39 16 30 18

1997 40 22 46 25 59 29 63 34 78 45 82 51 88 55 91 53 82 47 66 33 52 27 38 23mean

10-yr 35 20 43 23 56 31 65 38 74 46 82 53 90 57 89 54 81 46 67 35 47 27 38 20mean

53-yr 35 19 43 25 55 31 64 37 74 45 82 52 91 57 90 55 80 46 65 36 48 28 37 22mean

Table 5. Cumulative monthly growing degree-days (50-86 °F). Malheur ExperimentStation, Oregon State University, Ontario, Oregon, 1988-1997.

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec1,988 0 5 56 236 554 1,139 2,050 2,741 3,117 3,426 3,446 3,4461,989 0 0 13 197 469 1,018 1,751 2,332 2,721 2,838 2,852 2,8521,990 2 9 88 327 588 1,085 1,819 2,454 3,039 3,077 3,077 3,0771,991 0 13 29 153 365 754 1,530 2,248 2,684 2,878 2,879 2,8791,992 0 13 119 321 803 1,377 2,016 2,720 3,105 3,279 3,283 3,2831,993 0 0 23 104 527 885 1,349 1,873 2,281 2,533 2,539 2,5391,994 0 2 94 283 652 1,175 1,969 2,743 3,252 3,396 3,398 3,3981,995 0 29 61 167 460 893 1,573 2,161 2,633 2,734 2,737 2,7471,996 0 5 58 193 436 929 1,687 2,345 2,709 2,903 2,921 2,9231,997 4 4 85 202 621 1,130 1,791 2,497 2,977 3,134 3,154 3,154Mean 1 8 63 218 548 1,034 1,754 2,411 2,852 3,020 3,029 3,030

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Table 6. Monthly degree-days (86-104 °F). Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1990-1997

Year Apr May Jun Jul Aug Sep Oct1,990 0 0 13 56 41 14 01,991 0 0 2 41 36 4 01,992 0 5 20 23 54 2 01,993 0 4 4 2 11 5 01,994 0 2 16 68 54 7 01,995 0 0 4 23 22 7 01,996 0 0 5 54 32 4 01,997 0 4 0 27 31 5 0mean 0 2 8 37 35 6 0

Table 7. Monthly 4 inch soil temperature. Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily

High low High low High low High low High low High low High low High low High low High low High low High low

°F

Max. 47 44 50 40 65 51 75 56 89 71 90 73 95 80 95 80 85 77 72 67 53 53 47 45

Min. 31 29 32 32 39 35 53 41 59 47 72 61 62 61 80 72 67 62 52 51 45 44 37 37

1997 35 34 38 33 52 41 62 47 71 56 85 67 92 75 89 72 77 62 63 52 48 40 36 34mean

10-yr 33 32 39 35 51 42 62 50 73 59 81 67 89 74 87 74 78 66 63 53 45 40 35 33mean

31-yr 33 32 38 34 51 41 62 48 74 58 82 67 90 75 88 74 77 64 61 51 44 39 34 33mean

Table 8. Pan-evaporation totals. Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

Totals April May Jun Jul Aug Sep Oct Total Daily inches Mean 0.21 0.28 0.35 0.36 0.35 0.24 0.17Max. 0.35 0.5 0.47 0.55 0.55 0.39 0.46Min. 0.01 0.07 0.16 0.06 0.18 0.09 0.04

Annual inches 1997 6.17 8.66 10.43 11.06 10.82 7.32 5.38 59.84

10-yr mean 6.1 9.01 9.81 11.83 ' 10.42 7.59 4.36 59.1248-yr mean 5.54 7.6 8.8 11.1 9.5 6.19 3.09 51.15

Table 9. Last and first frost (<32 °F) dates and number of frost-free days. MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1976-1997.

Date of last frost Date of first frost Total number ofYear Spring Fall frost-free days

1,976 Apr 23 Oct 5 165

1,977 Apr 20 Sep 22 155

1,978 Apr 23 Oct 14 174

1,979 Mar 20 Oct 27 221

1,980 Apr 13 Oct 17 187

1,981 Apr 14 Oct 1 170

1,982 May 5 Oct 5 153

1,983 Apr 27 Sep 20 146

1,984 May 7 Sep 25 141

1,985 May 13 Sep 30 140

1,986 May 23 Oct 12 142

1,987 Apr 21 Oct 11 173

1,988 May 2 Oct 30 181

1,989 May 19 Sep 13 117

1,990 May 8 Oct 7 152

1,991 Apr 30 Oct 4 157

1,992 Apr 24 Sep 14 143

1,993 Apr 20 Oct 11 174

1,994 Apr 15 Oct 6 174

1,995 Apr 16 Sep 22 159

1,996 May 6 Sep 23 139

1,997 May 3 Oct 8 158

Mean April 26 October 4 161

Table 10. Daily wind-run totals and monthly totals, Malheur Experiment Station, OregonState University, Ontario, OR, 1997.

Total Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily miles

Max. 278 180 168 226 172 145 118 105 127 231 88 163

Min. 24 15 30 38 14 33 30 27 25 18 22 12

Mean 58 64 81 99 64 78 61 54 60 86 50 53

Annual miles

1,997 1,787 1,792 2,513 2,970 1,981 2,331 1,877 1,686 1,808 2,668 1,491 1,594

10-yr 2,247 2,369 1,983 1,774 1,597 1,562 1,660mean

49-yr 2,110 1,891 1,531 1,449 1,291 1,228 1,252

mean

FINAL YEAR RESULTS OF THE 1992 TO 1997 ALFALFA VARIETY TRIAL

Eric P. Eldredge, Monty Saunders, and Clinton C. ShockMalheur Experiment Station

Oregon State UniversityOntario, Oregon

Introduction

The purpose of this furrow irrigated trial was to compare the forage productivity of 35alfalfa varieties through five years based on four harvests per year. The alfalfa varietiesplots were planted September 16, 1992, and were sprinkler irrigated for seedgermination and stand establishment.

Methods

Yield samples were taken by harvesting a 3 foot by 22 foot swath from the center ofeach plot with a flail forage harvester. At each cutting date, moisture content wasdetermined by drying samples from eight randomly selected plots. Fresh weight offorage was converted to 88 percent dry matter (DM) for all varieties. Hay cutting dateswere May 15, July 3, August 7, and September 22, 1997. Forage quality of eachvariety was analyzed by near-infrared reflectance spectrophotometry (NIRS) to estimatepercentage crude protein (CP) and percentage acid detergent fiber (ADF). Samples of20 stems were taken from each plot at the third cutting, dried, ground to powder, andsubmitted for NIRS analysis. Variety performance was compared using ANOVA andleast significant differences (LSD).

Results

The average hay production at 88 percent dry matter in the trial was 9.2 ton/acre (Table1). Averages for the first through fourth cuttings were 2.2, 2.1, 3.2, and 1.7 ton/acre,respectively. The varieties are ranked by total production in 1997, from highest tolowest, with the 24 top-yielding varieties producing 9 ton/acre or more. The averagehay production at 88 percent DM of all varieties in the trial over five years was 49.5ton/acre (Table 2).The information on variety resistance to diseases and pests (Table 3)was provided by participating seed companies and the Certified Alfalfa Seed Council.Most of the varieties have some degree of susceptability to diseases and pests thatcould limit hay production in our area. Growers should choose varieties that have higherresistance ratings to known disease or pest problems as well as demonstrated yieldpotential.

Table 1. Yield by cuttings and total yield at 88 percent dry matter, 35 alfalfa varieties,Oregon State University Malheur Experiment Station, Ontario, OR, 1997.

1st 2nd 3rd 4th Total Crude5/15 7/3 8/7 9/22 1997 protein ADF1

Variety Source ton/acre Garst 630 ICI Americas 2.4 2.4 3.6 1.8 10.2 18.16 38.35Archer America's Alfalfa 2 2.5 3.6 2 10.1 22.65 31.79WL 317 W-L Research 2.3 2.2 3.4 1.9 9.8 20.89 33.89PSS 393 Price & Sons 2.2 2.2 3.7 1.7 9.8 19.96 35.77Nemagone ABI 2.1 2.4 3.9 1.9 9.8 22.64 31.21DK133 DeKalb 2.2 2.3 3.3 1.9 9.7 22.35 31.733 J 15 Union Seed 2.2 2.3 3.4 1.8 9.7 23.01 31.011-A Candy Co. 2.3 2.3 3.2 1.9 9.7 18.97 36.98Ovation W-L Research 2.2 2.2 3.3 1.9 9.6 20.35 34.79Achieva Allied Seed 2.1 2.1 3.4 1.9 9.6 19.69 35.89ABI 9151 ABI 2 2.2 3.6 1.8 9.6 22.21 32.99Hyland Oasis Seed 2 2.2 3.5 1.8 9.5 20.33 35.53Sutter PGI / MBS 2 2.1 3.7 1.7 9.4 18.96 36.06Asset Allied Seed 2.2 2.3 3.1 1.8 9.4 20.89 33.98WL 323 W-L Research 2.2 2.2 3.1 1.8 9.3 20.57 35.61Excalibur II Allied Seed 2 2.3 3.1 1.8 9.3 20.45 35.17ABI 9160 ABI 1.9 2 3.6 1.8 9.3 20.65 34.33WL 320 W-L Research 2 2.3 3 1.8 9.2 22.25 32.62Vernema USDA / WSU 2.3 2.3 3 1.6 9.2 20.4 35.23Lobo Seed Tec 2.1 2.2 2.9 1.9 9.2 22.21 32.67Blazer-XL Union Seed 2.2 2.1 2.9 1.9 9.2 20.44 36.04cv5472 Pioneer Hi-Bred 2.3 2.2 3.2 1.5 9.2 19.52 35.11Lahontan USDA / U NV 2.4 2.2 2.9 1.6 9.1 20.32 34.77WL 322 HQ W-L Research 2.2 2.1 2.9 1.8 9 19.46 35.33Crystal PGI / MBS 1.9 2.2 3.1 1.7 8.9 20.98 33.46Perry USDA / U NB 2.3 2 2.8 1.7 8.8 20.12 36.21Washoe USDA / U NV 2.2 1.9 3 1.6 8.7 20.94 33.79Maxi-Leaf Ray Brothers 2.2 1.9 3 1.6 8.7 21.59 33.56Future Ray Brothers 2 2 3 1.7 8.7 20.26 34.72cv5683 Pioneer Hi-Bred 2.1 1.8 3.1 1.6 8.6 20.14 34.551-T-11 Candy Co. 2.1 2 2.8 1.6 8.5 22.28 31.53Wrangler USDA \ U NB 2 1.9 2.7 1.6 8.2 21.82 33.23PGI 2152 PGI / MBS 2.2 2 3 1.7 8.1 21.35 33.83cv5364 Pioneer Hi-Bred 2.3 1.9 2.5 1.5 8.1 18.79 37.12CUF-101 USDA / UC 2.7 1.5 2.5 1.3 8 20.06 33.36Mean 2.2 2.1 3.2 1.7 9.2 20.73 34.35 LSD (0.05) NS 0.3 0.5 2.6 1.2 NS NS CV (%) 15.3 10.0 15.4 10.6 9.41 ADF: acid detergent fiber2NS: not significant

8

Table 2. Five-year forage yields, 35 alfalfa varieties, Oregon State University MalheurExperiment Station, Ontario, OR, 1997.

5-year 5-yearVariety 1993 1994 1995 1996 1997 average total ton/acre

Archer 12.9 10.9 8.9 9.6 10.1 10.5 52.4Achieva 12.7 11.1 8.9 9.9 9.6 10.4 52.2Lobo 13.5 10.9 9.0 9.5 9.2 10.4 52.1Nemagone 12.7 10.8 9.0 9.7 9.8 10.4 52.0Garst 630 12.7 10.5 8.7 9.5 10.2 10.3 52.6DK133 13.2 10.8 8.4 9.4 9.7 10.3 51.5ABI 9151 12.4 10.4 9.0 9.4 9.6 10.2 50.8Excalibur II 12.6 10.6 8.7 9.6 9.3 10.2 50.81-A 12.7 10.6 8.5 9.0 9.7 10.1 50.7Sutter 12.4 10.6 8.6 9.3 9.4 10.1 50.3WL 323 12.2 10.7 8.7 9.3 9.4 10.1 50.3Blazer-XL 12.9 10.6 8.3 9.1 9.2 10.0 50.1Asset 12.5 10.2 8.8 9.1 9.4 10.0 50.0Hyland 12.3 10.5 8.6 9.0 9.6 10.0 50.03 J 15 12.1 10.3 8.7 9.0 9.7 10.0 49.8PGI 2152 13.1 10.6 8.8 9.2 8.1 10.0 49.8cv5683 12.7 10.8 8.6 9.1 8.6 10.0 49.8ABI 9160 12.3 10.7 8.4 9.0 9.3 10.0 49.7cv5472 12.2 10.7 8.5 9.1 9.2 9.9 49.7WL 317 12.3 10.3 8.1 9.1 9.8 9.9 49.6WL 320 12.2 10.4 8.9 8.9 9.2 9.9 49.6Crystal 12.5 10.3 8.3 9.2 9.0 9.9 49.3Ovation 11.9 10.4 8.5 8.8 9.6 9.9 49.2Lahontan 12.5 10.1 8.4 8.8 9.1 9.8 48.9Vernema 11.7 9.9 8.6 9.2 9.2 9.7 48.6WL 322 HQ 11.9 10.4 8.3 8.8 9.0 9.7 48.41-T-11 12.2 10.2 8.2 9.0 8.5 9.6 48.1Washoe 11.8 10.0 8.4 9.1 8.7 9.6 48.0Wrangler 12.4 10.1 8.5 8.8 8.2 9.6 48.0Future 11.8 10.3 8.2 8.7 8.7 9.5 47.7Perry 11.7 9.6 8.5 8.8 8.8 9.5 47.4PSS 393 11.6 8.5 8.4 8.8 9.8 9.4 47.1Maxi-Leaf 12.2 9.8 7.9 8.5 8.7 9.4 47.1cv5364 11.8 9.8 8.0 8.7 8.1 9.3 46.4CUF-101 12.0 9.4 8.1 7.0 8.1 8.9 44.5Mean 12.4 10.3 8.5 9.1 9.2 9.9 49.5 LSD (0.05) 1.2 0.7 0.7 0.8 1.2 0.4 CV (%) 3.5

Table 3. Disease and insect resistance levels of 35 alfalfa varieties included in the1992-1997 alfalfa forage trial at Malheur Experiment Station, Oregon StateUniversity, Ontario, OR, 1997.

Variety orblend Source

Releaseyear

Resistance ratings'

FD2 BW VW FW AN PRR SAA PA SN AP RKN1-A Candy Co. 92.0 3.01-T-11 Candy Co. 92.0 5.03 J 15 Union Seed NR 3.0 HR3 R HR HR HR HR R R -cv5364 Pioneer Hi-Bred 89.0 4.0 R MR R MR MR HR HR Rcv5472 Pioneer Hi-Bred 89.0 4.0 HR MR HR MR MR R HR Rcv5683 Pioneer Hi-Bred 88.0 7.0 MR S R S R HR R RABI 9160 ABI NR 5.0 MR MR MR R R R R RABI 9151 ABI NR 5.0 MR MR HR MR R MRAchieva Allied Seed 3.0 R R HR HR HR R R MR RAP 8950 ABI NR 4.0 MR MR HR MR R HR HR R RArcher America's Alfalfa 88.0 5.0 MR LR HR MR R - MR -Asset Allied Seed 90.0 4.0 HR R R R HR R R MRBlazer-XL Union Seed 91.0 3.0 R R HR HR HR HR R R RCrystal PGI/MBS 90.0 4.0 HR R HR R HR LR R MR MRCUF-101 USDA/UC 76.0 9.0 HR - MR HR HR LR MRDK133 DeKalb 91.0 4.0 HR R HR HR HR R R MR RExcalibur II Allied Seed 93.0 4.0 HR R HR HR HR HR R R RFuture Ray Brothers 87.0 3.0 HR MR MR LR R MR MRGarst 630 ICI Americas 85.0 4.0 HR MR R MR R MR R R -Hyland Oasis Seed 93.0 3.0 HR R HR R HR R HR R MRLahontan USDA/U NV 54.0 6.0 MR S LR - LR MR LR R SLobo SeedTec 91.0 6.0 MR MR HR HR R HR R RMaxi-Leaf Ray Brothers 93.0 4.0 R LR MR R R - - -Ovation W-L Research NR 4.0 HR HR HR HR HR MR R MR RPerry USDA/U NB 79.0 3.0 R S R LR MR MR R - -PGI2152 PGI/MBS 92.0 5.0 HR R HR R R HR R MR -PSS 393 Price & Sons NR 6.0 -Sutter PGI/MBS 87.0 7.0 R LR HR LR HR HR R RVernema USDA/WSU 81.0 4.0 MR MR LR LR MR HRWashoe USDA/U NV 65.0 5.0 R - LR R R R RWL 322 HQ W-L Research 91.0 4.0 HR R HR MR R HR HR LR LRWL 320 W-L Research 85.0 4.0 R MR HR MR R R R MR -WL 323 W-L Research 93.0 4.0 HR R HR HR HR MR R R RWL 317 W-L Research 88.0 3.0 HR R HR R HR HR HR R MRWrangler USDA/U NB 83.0 2.0 R LR R LR HR HR HR

'BW bacterial Wilt, VW:Verticillium wilt, FW:Fusarium wilt, AN:Anthracnose, PRR:Phytophthora Root Rot, SAA:Spotted AlfalfaAphid, PA:Pea Aphid, SN:Stem Nematode, AP:Aphanomyces, RKN:Root Knot Nematode (Northern).

2Fall Dormancy (FD): 1:Norseman, 2:Vernal, 3:Ranger, 4:Saranac, 5:DuPuits, 6:Lahontan, 7:Mesilla, 8:Moapa 69, 9:CUF 101.

3Pest Resistance Rating: >50%=HR (high resistance), 31-50%=R (resistant), 15-30%=MR (moderate resistance), 6-14%=LR(low resistance), 0-6%=S (susceptable).

1 0

SECOND PRODUCTION YEAR OF THE ALFALFA FORAGEVARIETY TRIAL, 1996-2000

Eric P. Eldredge, Monty Saunders, and Clinton C. ShockMalheur Experiment Station

Oregon State UniversityOntario, Oregon, 1997

Introduction

The purpose of this alfalfa variety trial is to compare the yield of 32 alfalfa varieties overa five-year life of stand, when harvested for hay with four cuttings per year. The alfalfavarieties were replicated four times in a randomized complete block experimentaldesign. The variety trial was planted August 23, 1995. Plots were seven rows widespaced 7 inches apart on beds 60 inches wide by 20 feet long.

Methods

In the second production year, 1997, the first cutting was May 22. A 36 inch swath wascut from the center of each plot using a flail mower. The fresh hay was weighed, andmoisture content was determined by drying a sample of hay from each plot in the firstthree cuttings, and from ten randomly selected plots in the fourth cutting, in a foragedryer. Fresh weight of forage was converted to 88 percent dry matter (DM) for allvarieties. Forage quality of each variety was analyzed by near-infrared reflectancespectrophotometer (NIRS) to estimate percentage crude protein (CP) and aciddetergent fiber (ADF). Samples of 20 stems were taken from each plot at the thirdcutting, dried, ground to powder, and submitted for NIRS analysis. The regrowth afterthe first cutting was flail mowed May 29, and the field was corrugated for furrowirrigation. The first furrow irrigation was applied June 2, followed by irrigations June 12and 17. A second cutting was taken July 14. The sprinkler system was re-installed andthe field was sprinkler irrigated July 19, 20, 24, 28, and August 6. The third cutting wastaken August 13, followed by sprinkler irrigations Aug ust 22 and September 5, and thefourth cutting was taken September 22. Variety differences in yield and quality ofthird-cutting hay were compared using ANOVA and protected least significantdifferences at the 5 percent level.

Results

The average yield of all the alfalfa varieties in the trial for the second year for fourcuttings was 9.5 ton/acre, based on 12 percent moisture content (Table 1). Significantdifferences in yield were found in the first cutting at the 5 percent probability level. Theabsence of detectable differences in yield among the alfalfa varieties in subsequentcuttings may be attributable to excellent yield potential demonstrated by the cultivars inthis trial.

11

Table 1. Alfalfa variety trial, second-year forage yields, and third-cutting protein andADF, 88% dry matter, Malheur Experiment Station, Oregon State University,Ontario, OR, 1997.

1st 2nd 3rd 4th 1997 Crude5/19 7/15 8/13 9/22 Total protein ADF1

Variety or blend Source ton/acre

10.410.310.1

109.99.99.99.89.79.79.69.69.69.69.59.59.59.49.39.39.29.29.29.29.29.19.19.19.19.1

98.99.5

NS8.31

MP 2000RushmoreSterlingZX9351var 330TahoeGangbustersVernalSevelraColumbia 2000Wild CardW-L 252HQUN 13Laser 152Magnum IIIMagnum IVExcalibur IIGoliathAlfagrazevar92-31 FWranglerNitroLadakIdaho GoldZX9352RobustOrestanLahontanInnovator+ZABI 9252StaminaCUF-101MeanLSD (0.05)CV (%)

Cenex/Land'O LakesNorthrup KingCargill HybridsABI America's AlfalfaUnion SeedNorthrup KingRay BrothersPublicPublicAllied SeedUniversity of IdahoW-L ResearchUnion SeedJ-V SeedsDairyland SeedDairyland SeedAllied SeedBlack Canyon SeedABI America's AlfalfaW-L ResearchPublicPublicPublicBlack Canyon SeedABI America's AlfalfaGooding SeedPublicPublicABI America's AlfalfaABI America's AlfalfaAllied SeedPublic

3.7 3 1.7 1.93.7 2.8 1.8 23.8 2.7 1.8 1.83.5 2.5 2 23.6 2.5 1.8 23.8 2.5 1.7 1.93.8 2.5 1.6 1.93.5 2.7 1.7 23.4 2.6 1.7 1.93.7 2.5 1.7 1.83.2 2.4 1.9 2.13.6 2.3 1.8 1.83.5 2.5 1.7 1.93.4 2.5 1.8 23.5 2.2 1.8 23.7 2 1.9 23.3 2.5 1.8 1.93.8 2.3 1.6 1.83.4 2.4 1.7 1.83.2 2.3 1.8 1.93.5 2.2 1.6 1.93.2 2.2 1.9 1.93.4 2.2 1.8 1.83.5 2.1 1.7 1.93.4 2.1 1.9 1.93.3 2.2 1.7 23.2 2.3 1.7 1.83.2 2.3 1.7 1.83.2 2.1 1.8 1.93.2 2.2 1.7 1.93.2 2.3 1.7 1.93.1 2.2 1.6 23.5 2.4 1.8 1.9

0.43 NS 2 NS NS8.61 21.16 9.4 9.03

21.9422.2320.8622.1119.4120.8420.3720.7322.1720.0722.5721.9921.0121.1522.5921.7323.7622.5321.3521.6521.4620.5421.6620.8221.2120.9120.0219.0721.0120.4

22.9721.6221.33NS

33.5934.2335.2934.3636.5335.2635.4736.2934.2736.5634.7434.3435.9635.2332.8834.2431.5832.6634.4534.7833.9936.1633.9335.7134.6734.4336.8936.9734.2436.4132.4533.3534.75NS

'ADF: acid detergent fiber2 NS : not significant

12

USING DEGREE-DAY ACCUMULATIONS TO PREDICT LYGUSHATCHES IN ALFALFA SEED

Ben Simko and Dani Jo KreighMalheur County Extension Office

Oregon State UniversityOntario, Oregon 97914

Introduction

Numerous publications have described degree-day or physiological time requirementsfor Lygus bug (Lygus hesperus). However, little work has been done to test degree-daymodels for Lygus development in the Northwest alfalfa seed IPM system. The objectiveof this study was to validate a published degree-day model from the University ofCalifornia for Lygus development in Malheur County, Oregon seed production fields.Additionally the research included preliminary observations of whether this techniquecan be used as a decision aid in pest management for fieldmen and growers. Thisproject was initiated in 1995, and observations, were carried out for three consecutiveseasons.

Methods

Eleven fields were monitored for Lygus population trends in particular for peak onset ofthe first egg hatch. The fields were located in major seed production districts of thecounty including Adrian, Sunset Valley, Cairo, and Oregon Slope. Standard 180° sweepsamples were taken from fields on a weekly or semiweekly basis. Sweep samples werepreserved in glass jars containing -70 percent ethanol solution and returned to the lab.The samples were analyzed and detailed counts of all adult and nymphal instars ofLygus recorded. Sampling began in mid-April and continued through mid-August. At allfour sites, baseline population levels were observed prior to clean up (prebloom)insecticide treatments. Population trends and especially surges of 1st and 2nd nymphalemergence were noted during the course of the season. Cooperating growers reportedall insecticide applications including active ingredients, rates, treatment dates, andapplication methods. Maximum and minimum temperatures recorded at the MalheurExperiment Station were used with a University of California computer utility to calculateaccumulated degree-days. In addition, two instruments were tested to monitorphysiological time or degree-day accumulations: 1) the Datalogger (Omnidata)Biophenometer and 2) the HarvestGuard heat unit recorder. At each study site theinstruments were placed in a small instrument shelter located at the edge of the alfalfaseed field. The lower threshold of development on each degree-day accumulator wasset at 52 °F. Published lygus developmental requirements for egg hatch and peakemergence of first instars has been reported at 252 degree-days*. This value was used

13

to correlate with observed hatches in the field. The biofix is defined as the date whenone begins accumulating degree-days, usually associated with a biological event. Forthe first spring prebloom hatch, the biofix was set at January 1. For the subsequenthatch, during the bloom period, the biofix was set at the date of the first insecticide(cleanup) treatment. Observations were then carried out to determine if usingdegree-day accumulations accurately predicted observed hatches of Lygus bugs.

Results and Conclusions

Based on the data collected over three seasons from a total of eleven fields, thefollowing observations are drawn:

1. The first hatch (prebloom) of Lygus bugs was consistently predicted using a January1 biofix, a lower developmental threshold of 52 o F, and the accumulation of 252 -300 degree-days (published egg development requirement was 252). This eventoccurred about mid-May in all three seasons. Figures 1 and 2 show individual fieldresults from 1997. Figure 3 represents a three year summary and shows the 50percentile for cumulative capture of combined first and second intar nymphsoccurred at 280 degree-days.

2. Degree day accumulations explained most of the site specific differences for theoccurrence or the first hatch at the eleven study fields.

The observed first hatch event in May varied by as much a 7 - 10 days over the lastthree years. This season to season difference was predicted by the recordeddegree day accumulations (Figure 4).

4. A 252 degree day accumulation did not consistently predict the second, bloomperiod, hatch of Lygus when setting the biofix at the first insecticide treatment date.

5. There was very little variation in degree-day accumulations between theinstruments and use of University of California computer software degree-daycalculator inputted with local maximum/minimum temperature data (Figure 5).Both instruments were relatively simple to use.

14

Based on three seasons of observations, the use of degree-day accumulations mayhave some potential as a tool for the management of Lygus populations in alfalfa seed.Monitoring the egg development time (252 degree-day) may be helpful to predict the firstnymphal hatch and to optimize sampling and treatment schedules during the prebloomperiod. It is unclear if alternate management techniques for the first hatch will mitigatesubsequent hatches of Lygus or reduce insecticide costs during the bloom period.Further research is required to fully explore the utility of degree-day accumulators inintegrated approaches to Lygus management.

Grower Impacts

Researchers, selected growers, and seed company agronomists are encouraged to testthis technique at other sites and production regions. At this time the utility of usingdegree-day accumulators is not clearly established, although units can now bepurchased at a relatively small investment of around $200. Site-specific testing wouldallow further evaluation of this technique and create opportunities for growers toinnovate with this tool on their farms.

Literature Cited

*Pickel, C., N. C. Welch, and D. B. Walsh. 1990. Timing Lygus Sprays UsingDegree-Days in Central Coast Strawberries. Santa Cruz County Agricultural ExtensionPublication. University of California.

Figure 1. Comparison of a prebloom Lygus bug hatch with accumulated degree-daysrequired for egg development (252) in a commercial alfalfa field, Adrian, OR,1997.*

Averageinsects/sweep

10

• 1&2 Nymphs

÷ 3 Nymphs

.t.3, 4 Nymphs

5

04/29:230 5t2:237 5/5:265 5/9:307 5/12:357 522

Calender Date: Degree-Days*Lower threshold of development = 52°• Biofix = January 1, Accumulator = HarvestGuard

Figure 2. Comparison of a prebloom Lygus bug hatch with accumulated degree-daysrequired for egg development (252) in a commercial alfalfa seed field, MalheurExperiment Station/Cairo, Ontario, OR, 1997*.

Averageinsects/sweep20

15

10

5

0

182 Nymphs

-A- 3 Nymphs

.4a. 4 Nymphs

4/29:174 5/5:202 5/9238 5/12291 5/15:356 5/22:474 6/2:604

Ca lender Date:Degree-Days

*Lower threshold of development = 52° . Biofix = January 1, Accumulator= HarvestGuard

Figure 3. Three year summary (1995-1997) of the relationship of degree-dayaccumulations and cumulative percent small Lygus nymphs collected,Malheur County, OR (Biofix = January 1, Lower developmental threshold =52° F).

Instals Coilected(Cumulative % 1st & 2nd )

100

16

♦ Year-1995

• Year-1996

o Year-1997

Degree-day600

500

400

300

200

100

0 ' ' '

Degree-day600

.4- UC Model

Biophenometer

.49, HarvestGuard

500

400

300

200

100

0 • ,

Figure 4. Comparison of Lygus degree-day accumulations in a commercial alfalfa seedfield for 1995, 1996, and 1997, Cairo, Ontario, OR (Biofix = January 1, Lowerdevelopmental threshold = 52° F)

.4. 1995

.0. 1996

48,. 1997

1 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Julian date

Jan. 1 Feb.19 Spring April 10 May 10 May 30equinox

Date

Figure 5. Comparison of three methods of tracking Lygus bug degree-dayaccumulations, Malheur Experiment Station, Oregon State University, Ontario,OR, 1997 (Biofix = January 1, Lower developmental threshold = 52° F)

1/31 2/28 3/13 3/21 4/1* 4/9 4/15 4/24 4/28 4/29 5/2 5/5 5/9 5/12 5/15 5225/28 5/31

Date

EVALUATIONS OF SUPERSWEET CORN AND SWEET CORN VARIETIES

Erik B.G. Feibert, Clint C. Shock, Greg Willison and Monty SaundersMalheur Experiment Station


Introduction

Sweet corn and supersweet corn varieties were evaluated for agronomic andprocessing performance for use in the Treasure Valley of Oregon.

Methods

Two trials were conducted on an Owyhee silt loam following sugar beets. The field wasworked into 30-inch beds in the spring of 1997. Alachlor (Partner) at 3 lb ai/acre wasbroadcast and incorporated by rain on April 30. Nineteen supersweet corn (Sh 2) and 21sweet corn (Su l ) varieties were planted in separate trials. Each trial had a randomizedcomplete block design with five replicates. The seed had been treated with standardfungicide seed treatments applied by the respective companies. The supersweet cornvarieties were planted on May 1 and the sweet corn varieties on June 3 to avoid crosspollination between the two types. Seed was planted at a 2-inch depth using anAmalco Cone Seeder on a John Deere 77 Flexi Planter. The trials were furrow irrigatedon alternate furrows immediately after planting to assure uniform emergence.Thereafter the field was irrigated as necessary.

A soil sample taken on May 27, 1997, showed a pH of 6.9, 1.7 percent organic matterand 87 lb of available-N in the top two feet of soil. The field was sidedressed with ureaat 200 lb N/ac on June 11. The field was cultivated on June 3, and again on June 11immediately after the urea was sidedressed.

Emergence counts were made on May 12, May 14, and May 16 for the supersweetcorn and on June 23 for the sweet corn. The supersweet corn plots were thinned onMay 29 and the sweet corn plots were thinned on July 25 to 24,000 plants/acre (1 plantevery 8.71 inches). Final stand counts were taken after thinning in each plot.

Starting on July 5, the silk stage was evaluated for 20 plants in one of the middle tworows of each plot in the first replicate. Varieties were considered to be at the mid-silkstage when 40 to 60 percent of the plants were silking. About 16 days after the mid-silkstage, ear samples from the border rows were taken and analyzed for moisture contentto determine the stage of maturity. The target ear moisture content for harvest was 78percent for the supersweet corn varieties and 71 percent for the sweet corn varieties.

18

All ears in the central 15 feet of the middle two rows in each plot were picked andweighed. A 10-ear subsample was weighed, shucked, weighed, and evaluated forlength, maximum diameter, diameter 6 inches from the base, and kernel row number.Ear taper was calculated by the difference between the maximum diameter and thediameter at 6 inches from the base. Ear taper is a descriptive measure of ear shape;the higher the ear taper, the less cylindrical the shape of the ear.

A composite subsample consisting of five ears from each replicate of each variety (20ears total) was taken to the American Fine Foods processing laboratory and evaluatedfor moisture and processing recovery. The processing recovery was calculated as thepercentage of the weight of the unhusked ears that was recovered as cut corn.Processing recovery data for each variety, based on a composite sample, were notreplicated. Degree-days were measured and calculated by a biophenometer (OmnidataInternational, Logan, UT) at the Malheur Experiment station.

Data were analyzed by analysis of variance. Means separation was determined by theprotected least significant difference test.

Results and Discussion

Emergence for the supersweet corn started on May 9. Varieties Skipper and Crystalhad the highest stands on the first count on May 12 (Table 1). Final stand counts onMay 16 ranged from 36 to 95 percent and averaged 76 percent. Crystal, Bandit, andSkipper had among the highest stands on May 16. Stand counts after thinning showedplant populations to be lower than the target of 24,000 plants/ac.

Yields of unhusked ears ranged from 9 to 13 tons/acre (Table 2). Shaker, XPH3129,and Marvel were among those with the highest yields. HMX5375, Assure, Maverickand XPH3129 were among those with ears with the least taper (most cylindrical ears).Recovery of cut corn ranged from 25 to 47 percent among varieties. XPH3129,FMX435, Marvel, and Contender were among those with the highest cut corn yields.

Emergence for the sweet corn varieties started on June 10 and plant stands rangedfrom 64 to 96 percent on June 23 (Table 3). Plant populations after thinning were closeto or at the target of 24,000 plants/acre for most varieties. Plant populations of lessthan 23,000 plants/acre were associated with final emergence of less than 80%.

Yields of unhusked ears ranged from 6.4 to 10.6 tons/acre. Excalibur, EX8410377,Chase and StylePak had ears among those with the least taper (most cylindrical ears).Recovery of cut corn ranged from 31 to 48 percent. Missing data for recovery was dueto delays in processing of some of the sweet corn variety samples which renderedthose samples unusable. EX8414297 and EX8410367 were among those with thehighest cut corn yields.

19

Table 1. Supersweet corn stand counts for corn planted on May 1 with emergencestarting on May 9. Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

Variety

Stand count

Seed source'May 12 May 14 May 16

Shaker 1 17.3 73.5 79.5XPH3129 1 15 65.8 75.7

Marvel 5 29 68 73.3FMX435 2 21.8 63 69.2

SS Jubilee 3 17.3 66.7 77.0Contender 5 35.2 68.5 72.2Endeavor 1 39.5 82.5 85.5

Bandit 2 46.8 91.5 92.5Assure 5 25.7 64.3 67.8

Lexus FM 2 15 72.8 80.3Crystal 1 55.2 90.3 95.2Zenith 2 38.7 67.3 74.2

GSS 7831 3 25.8 64.2 68.2Skipper 5 57.3 87.3 89.7

HMX5375 2 21.7 60 66.5Trigger 5 40.2 78.5 81.0Sheba 1 45.3 80 83.32610A 4 7.7 29.7 36.0

Maverick 1 35.5 77.7 82.3Average 31.1 71.1 76.3

LSD (0.05) 9.6 8.6 8.6'Sources: 1: Asgrow, 2: Harris Moran, 3: Rogers/Sandoz, 4: ScottSeed,

20

Table 2. Plant development, yield, and ear characteristics of supersweet corn varieties, Malheur Experiment Station,Oregon State University, Ontario, Oregon, 1997.

Degree-daySeed Days to Days to s to Harvest date Ear Ear Ear Cut corn

Variety source' mid-silk2 harvest2 harvest' Plant Pop." Yields weight length diam. Taper6 Rows Moisture Recovery' yield

plants/acre tons/acre lb --- inches --- t/ac

Shaker 1 65 84 1,525 19,863 13.0 July 31 0.54 8.8 1.8 0.39 16.5 78.4 25 3.3

XPH3129 1 73 92 1,723 19,980 12.3 Aug. 8 0.85 9.3 2.2 0.37 18.3 77.2 47 5.8

Marvel 5 65 85 1,548 20,444 12.0 Aug. 1 0.77 8.9 2.2 0.42 18.5 80.5 40 4.8

FMX435 2 69 90 1,667 19,166 11.9 Aug. 6 0.80 8.8 2.2 0.48 17.4 76.2 45 5.4

SS Jubilee 3 70 90 1,667 20,677 11.8 Aug. 6 0.69 8.3 2.0 0.47 17.1 75.9 39 4.6

Contender 5 63 83 1,507 18,818 11.5 July 30 0.75 8.8 2.2 0.45 16.5 77.7 42 4.8

Endeavor 1 64 85 1,548 22,070 11.4 Aug. 1 0.68 8.4 2.1 0.46 17.8 80.0 36 4.1

Bandit 2 68 89 1,642 21,257 11.0 Aug. 5 0.70 7.9 2.1 0.53 17.7 78.5 40 4.4

Assure 5 72 91 1,696 20,328 10.9 Aug. 7 0.64 8.7 1.8 0.33 17.1 78.4 36 3.9

Lexus FM 2 72 90 1,667 20,096 10.8 Aug. 6 0.61 8.3 1.9 0.44 18.9 71.0 37 4.0

Crystal 1 72 91 1,696 21,025 10.8 Aug. 7 0.61 8.0 1.9 0.44 17.0 74.9 39 4.2

Zenith 2 72 91 1,696 19,399 10.8 Aug. 7 0.55 7.5 1.7 0.40 17.3 77.0 33 3.6

GSS 7831 3 66 85 1,548 18,353 10.7 Aug. 1 0.66 8.0 2.1 0.48 17.7 78.9 37 4.0

Skipper 5 72 90 1,667 21,838 10.6 Aug. 6 0.62 8.5 1.9 0.48 17.6 76.4 30 3.2

HMX5375 2 72 91 1,696 19,631 10.4 Aug. 7 0.57 7.9 1.7 0.32 17.4 75.9 32 3.3

Trigger 5 70 90 1,667 18,934 10.3 Aug. 6 0.69 8.8 2.0 0.43 18.1 76.3 41 4.2

Sheba 1 62 78 1,388 18,586 10.3 July 25 0.59 8.6 2.0 0.49 14.5 79.4 31 3.2

2610A 4 67 89 1,642 13,823 9.5 Aug. 5 0.69 8.3 2.0 0.45 16.6 75.3 36 3.4

Maverick 1 72 91 1,696 18,934 9.1 Aug. 7 0.56 8.2 1.7 0.36 14.9 74.2 38 3.5

Average 69 88 1,626 19,643 11.0 0.66 8.4 2.0 0.43 17.2 77.0 37.1 4.1

LSD (0.05) 3,316 1.0 0.05 0.2 0.1 0.07 NS

'Sources: 1: Asgrow, 2: Harris Moran, 3: Rogers/Sandoz, 4: ScottSeed, 5: Crookham 2From emergence.

'Degree-days (50 - 86 °F) from emergence. "After thinning. 5 Yield of unhusked ears.

6 Maximum diameter minus diameter 6 inches from the base. 7 Percentage of unhusked ear yield recovered as cut corn.

NS: not significant.

Table 3. Plant development, yield, and ear characteristics of sweet corn varieties, Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

Degree-Seed Days to Days to days to Emergence Plant

Variety source' mid-silk2harvest2harvest' June 23 population's YieldsOA

EX8410367 1 56 80 1,688 82.8 25,323 10.6

EX8414297 1 54 79 1,667 88.5 25,091 10.0

EX8410347 1 53 80 1,688 93.7 23,116 9.8

HMX5371 2 55 80 1,688 74.5 22,767 9.5

EX8410357 1 53 77 1,624 93.8 23,232 9.4

EX8410377 1 55 79 1,667 96.0 23,581 9.4

HMX5372 2 48 80 1,688 74.8 22,070 9.3

XPH3125 1 52 76 1,604 84.0 24,626 9.0

G. Jubilee 3 54 77 1,624 84.0 22,419 8.9

Fantasia 1 50 73 1,539 88.2 24,510 8.6

HMX5373 2 56 84 1,777 89.2 25,091 8.5

GH 1887 3 45 73 1,539 83.0 24,045 8.4

26,717 4 53 76 1,604 85.0 23,232 8.4

Sequel 1 55 77 1,624 82.3 23,813 8.4

Chase 1 51 72 1,516 89.8 23,464 8.2

26490A 4 59 85 1,798 81.8 23,232 7.9

Legacy 2 58 84 1,777 75.0 22,884 7.7

StylePak 2 57 85 1,798 90.1 24,045 7.6

Excalibur 2 56 84 1,777 76.2 21,141 7.4

Lexus 2 51 76 1,604 79.0 22,535 7.3

HMX5374 2 59 85 1,798 64.2 21,838 6.4

Average 54 79 1,671 83.6 23,431 8.6

LSD (0.05) 7.0 2,119 1.1

Harvest Eardate weight

lb

Aug. 29 0.79

Aug. 28 0.69

Aug. 29 0.71

Aug. 29 0.64

Aug. 26 0.70

Aug. 28 0.68

Aug. 29 0.78

Aug. 25 0.68

Aug. 26 0.62

Aug. 22 0.52

Sept. 2 0.66

Aug. 22 0.54

Aug. 25 0.57

Aug. 26 0.66

Aug. 21 0.57

Sept. 3 0.74

Sept. 2 0.70

Sept. 3 0.66

Sept. 2 0.69

Aug. 25 0.56

Sept. 3 0.67

0.7

0.04

Cut cornEar Ear yield

length diam. Taper6 Rows Moisture Recovery'

--- inches --- tons/acre

2.1 0.36 17.5 73.7 43 4.6

2.2 0.66 17.9 68.8 47 4.7

2.0 0.41 18.2 71.7 39 3.8

2.0 0.47 19.3 71.9 36 3.4

2.1 0.44 19.0 74.6 46 4.3

1.9 0.22 19.2 71.8 37 3.5

2.1 0.44 17.9 71.0 46 4.3

2.0 0.40 14.4 70.3 45 4.1

1.9 0.42 17.9 71.7 36 3.2

1.7 0.33 16.8 74.0 31 2.7

2.1 0.54 18.5 72.8

1.8 0.39 19.4 74.7 33 2.8

1.9 0.45 18.1 69.7 34 2.9

2.0 0.40 17.6 74.8 38 3.2

1.8 0.28 14.0 72.0 42 3.4

2.0 0.33 18.7 71.3

2.0 0.36 21.6 69.6

1.9 0.30 21.3 71.1

1.8 0.17 22.1 69.6

1.8 0.38 16.1 71.8 48 3.5

2.0 0.43 19.2 71.9

2.0 0.39 18.3 71.8 29 2.6

0.1 0.15 3.5

plants/acre tons/acre

8.7

8.1

8.5

8.2

8.2

9.2

9.0

8.5

8.4

8.2

8.2

8.5

8.3

8.3

8.4

9.2

8.7

7.6

8.4

8.3

7.9

8.4

NS

'Seed sources: 1: Asgrow, 2: Harris Moran , 3: Rogers/Sandoz , 4: Scottseed

2From emergence. 'Degree-days (50 - 86 °F) from emergence. 'After thinning. 'Yield of unhusked ears.

6 Maximum diameter minus diameter 6 inches from the base. 7 Percentage of unhusked ear yield recovered as cut corn. 'NS: not significant

NITROGEN VALUE OF POTATO AND ONION SLUDGEFOR CORN PRODUCTION

Clinton C. Shock, Erik B. G. Feibert, Monty Saunders, and Gary SchneiderMalheur Experiment Station


Summary

Three alternative treatments to provide nitrogen-potato sludge, a mixture of potato andonion sludge, and a chemical N fertilizer-were applied to a bench soil. Bench soils areof low fertility and are located on the benches above the deep, fertile alluvial soils in thevalley bottom. The two sludge treatments were applied and incorporated beforeplanting field corn. The sludges were applied at a rate to result in 200 lb N/acreavailable to the corn, based on the anticipated mineralization rate of the sludges. Thechemical N fertilizer was sidedressed after planting at 200 lb N/acre. Sludge amendedand chemical N fertilized plots had significantly higher forage and grain yields than didthe unfertilized check plots. Both the sludge amended plots and the plots treated withchemical N fertilizer produced favorable yield and quality of forage and grain.

Introduction

The processing of potatoes into frozen French fries generates a substantial amount ofliquefied refuse. This refuse is partially dehydrated resulting in a sludge theconsistency of gelatin (80% moisture). Another waste of agricultural industry resultsfrom the extraction of onion oil from cull onions; the resulting sludge is not dehydrated.The disposal of these sludges incurs costs to the processors. With increasedrestrictions and costs of landfill disposal, application of the sludges to agricultural landcould be an alternative. To establish guidelines for application, waste mineralizationrates in soil and their effect on crop yields needs to be determined. The land applicationof the sludges could not only benefit the processors, but could also benefit the growersby allowing lower cost sludge to substitute for chemical fertilizers. Since the onionsludge is not dehydrated, the application of pure onion sludge is difficult. The mixture ofpotato and onion sludges, however, results in a consistency that is practical for landapplication. This trial tested the effect of potato sludge or a mixture of potato and onionsludges on field corn yield, quality, and N recovery.

23

Materials and Methods

The trial was conducted on Nyssa silt loam with 1.5% organic matter, a pH of 8.1, and23 ppm P, 137 ppm K, 2690 ppm Ca, 330 ppm Mg, 156 ppm Na, 1.7 ppm Zn, 12.8 ppmFe, 5.8 ppm Mn, 1 ppm Cu, 10 ppm SO 4-S, and 0.5 ppm B.

The 4 treatments were an unfertilized check, potato sludge, potato/onion sludge mix,and N fertilizer. The experimental design was a randomized complete block with fivereplicates. The plots were 20 rows wide and 50 feet long.

The sludge application rate was determined by having a target of 200 lb/acre ofavailable N released the first year based on a 20 percent N mineralization rate. Thepotato sludge had a 20 percent dry matter (DM) content and 5.52 percent N (DM basis)and the mixed sludge had a 11.9 percent dry matter content and 4.83 percent N. Thepotato sludge was applied at 50 tons/acre (wet weight) and the potato/onion sludge mixwas applied at 100 tons/acre (wet weight). The proportion of the sludges in the mix was44% potato and 56% onion by weight and was based on the annual output of thesludges from the respective processing facilities. The potato/onion sludge mix wasprepared by weighing each sludge separately and then mixing both in a Rotomix feedtruck (Rotomix Co., Dodge City, KS).

The potato sludge and the potato/onion sludge mix were applied on April 7 using aTerragator applicator (Ag. Chem. Ind. Div., Minetonka, MN) equipped with a Knight"Slinger box" (Knight Manufacturing, Brodhead, WI). The sludge was side dischargedfrom the slinger box and broadcast by flails located in the discharge outlet. TheTerragator was calibrated separately for the potato sludge and potato/onion sludge mix.

The field was disked and bedded to 30 inch centers on April 25. On May 6, acomposite soil sample of all plots in each treatment from the first and second foot of soilwas taken and air dried for determination of N mineralization by anaerobic incubation.

Alachlor at 3 lb ai/acre was broadcast and incorporated with a bed harrow on May 12.Seed of field corn variety 3489 (Pioneer) was planted on May 13 at 27,000 seeds/acre.The field was cultivated on June 4 and again on June 12 after sidedressing the Nfertilizer plots. The N fertilizer plots had urea at 200 lb N/acre sidedressed on June 12,30 days after planting. The field was furrow irrigated as necessary in alternate furrowswith the irrigated furrows alternating at each irrigation.

Stand counts and plant heights were taken on June 18 in each plot. The mid-silk stagewas determined for each plot by the number of plants in silk out of a sample of 20.Twenty-four first fully developed leaves were sampled on June 25 and 24. Leaves-immediately above the ear node were sampled on August 1 (at silking) from the tworows adjacent to the central two rows in each plot. The leaf samples were analyzed forN, P, and K. The soil in each plot was sampled to a 6-foot depth in one foot incrementsin April before the sludge application and again after harvest.

24

Forage and grain harvest was started when the kernels reached approximately 30percent moisture on October 1. All the plants in 10 feet of a row adjacent to the centralharvest area in each plot were cut at ground level and weighed. The ears wereremoved and weighed and then the stalks and ears were shredded in a manner toresult in a uniform mixture of the ears and stalks. A subsample of the shredded plantswas taken for moisture content determination and total N analysis. All ears from thecentral 33 feet of the middle two rows in each plot were harvested, weighed, dried in aforced air drier, and then shelled with a Wintersteiger Nurserymaster small plotcombine. The shelled corn was weighed and a subsample was taken for determinationof moisture content. Shelled corn yields were corrected to 12 percent and 30 percentmoisture. Subsamples of the whole shredded plants and of the shelled corn wereanalyzed for total N.

The soil was sampled in one-foot increments down to six feet in each plot beforeplanting and after harvest and analyzed for nitrate and ammonium. The N balanceswere calculated by subtracting the post harvest accounted nitrogen (crop N uptake plusavailable soil N after harvest) from the nitrogen supply (available soil N in spring pluschemical fertilizer N plus N from irrigation water). Nitrogen contribution from theirrigation water was measured to be 1.5 ppm nitrate and ammonium-N or 8 lbN/acre-inch/acre of water infiltration assuming 2 acre-feet/acre of infiltration. Nitrogencontribution from organic matter mineralization was estimated by anaerobic incubationat 104 °F for 7 days.


Application of the sludges did not result in any differences in plant stand compared tothe unfertilized check or to the N fertilizer treatments. Average plant stand was 18,687plants/acre. The application of the sludges with the Terragator resulted in a uniformspreading on the soil surface. The 3-week period between the sludge application andthe incorporation allowed for drying of the sludge, making the incorporation moreeffective, and avoiding any interference with seed emergence due to disuniform soilstructure.

The check and N sidedressed plants were significantly shorter than the sludge treatedplants on June 18 (Table 1).

The unfertilized check treatment plants had significantly lower leaf N concentration thanthe other treatments on June 25 and at silking on August 1 (Table 1). The leaf Nconcentration for the check plants at silking was below the sufficiency range.

The N fertilized plants had significantly lower leaf P concentration than the othertreatments on June 25. With the P supply rate of the soil being the same for the checkand N fertilized plants, the P in the faster growing N fertilized plants could have becomediluted, compared to the slower growing check plants. The sludge treated plants

25

June 18Plant height

feet

June 25 August 1

Treatment P P

probably obtained a higher P supply from sludge mineralization. Leaf P and Kconcentrations at silk were within the sufficient range for all treatments.

The two sludge treatments and the N fertilizer treatment produced favorable grain yield(Table 2), grain total N, grain total protein, whole plant dry matter yield, whole plant totalN, and whole plant total protein (Table 3) with no statistically significant difference. Theunfertilized check treatment had significantly lower grain yield, grain total N, grain totalprotein, whole plant dry matter yield, whole plant total N, and whole plant total proteinthan the other treatments.

The soil available N balances were positive, both in the profile (0-6 feet, Table 4) and inthe top 2 feet (Table 5), in order from lowest to highest: N fertilizer, unfertilized check,potato sludge, and sludge mix. The soil N balances suggest that sludge Nmineralization released substantial available N. The N fertilizer treatment was probablysubject to leaching.

Literature Cited

Jones, J.B., Jr., H.V. Eck, and R. Voss. 1990. Plant analysis as an aid in fertilizing cornand grain sorghum. p. 521-547. In: Westerman, R. L. (ed.) Soil testing and plantanalysis. SSSA Book Series, no. 3. SSSA, Madison, WI.

Table 1. Plant height and nutrient concentration of first fully developed leaf on June 25and of ear leaf at silking on August 1. Malheur Experiment Station, OregonState University, Ontario, Oregon, 1997.

Leaf nutrient concentration

CheckPotato sludgeSludge mix'N fertilizerLSD (0.05)

1.31 2.45 0.31 1.98 1.78

1.82 2.89 0.34 2.06 2.91

1.84 2.95 0.34 2.22 3.00

1.15 2.93 0.27 1.95 2.75

0.26 0.35 0.04 NS 0.44

0.22 2.890.27 2.870.27 2.860.26 2.81NS NS

Sufficiency range2

2.1-4.0 0.18-0.5 1.7-3.0'Potato/onion sludge mix (44%/56%)2for ear leaves at silk according to Jones et al. (1990).

26

Table 2. Corn yield response to potato and onion sludge application compared to Nfertilizer, Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1997.

TreatmentGrain moisture 2

Grain yield

12% moisture 30% moisture0/0 bu/acre3

Check 30.5 120.4 151.3Potato sludge 32.1 195.0 245.1Sludge mix' 31.4 218.2 274.3N fertilizer 32.6 196.1 246.5LSD (0.05) NS 31.9 40.1

'Potato/onion sludge mix (44%/56%)eat harvest356 Ib/bu

Table 3. Forage yield, N content, and estimated protein content of corn in response topotato and onion sludge application compared to N fertilizer, MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1997.

Kernel Whole plant

Yield' N Total Estimated Drycontent N protein2 matter

DMyield

N Totalcontent N

Estimatedprotein2

Treatment t/acre 0/0 ---- lb/acre ---- t/acre OA ---- lb/acre ----Check 4.2 0.93 55.3 345 44.8 11,301 0.78 87.7 548

Potato sludge 6.9 1.31 123.7 773 44.9 16,048 0.92 147.6 922Sludge mix' 7.7 1.24 133.2 833 43.9 17,074 0.97 165.4 1,034N fertilizer 6.9 1.38 131.5 822 44.3 17,145 0.97 165.8 1,037LSD (0.05) 1.1 NS 27 78 NS 2,013 0.11 24 150

1 30% moisture2Total N X 6.25'Potato/onion sludge mix (44%/56%)

27.

Table 4. Soil N balances for the 0 to 6 foot depth in response to land application ofpotato and onion sludges. Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

N supply Fall nitrogen accounting

Pre-plant N in Fall soilsoil available Fertilizer irrigation available Plant N Accounted Balance'

N (0-6') N water N (0-6') recovery N

Treatment lb/acre

Check 187.2 0 8 229.6 87.7 317.3 122.1

Potato sludge 182.9 0 8 259.8 147.6 407.3 216.4

Sludge mix2168.9 0 8 335.6 165.4 501.0 324.1

N fertilizer 149.3 200 8 226.1 165.8 391.9 34.6

LSD (0.05) 22.7 - - 46.1 24.0 45.4 58.2

'based on the difference between all N supplies and fall N accounting.

2Potato/onion sludge mix (44%/56%).

Table 5. Soil N balances for the 0 to 2 foot depth in response to land application ofpotato and onion sludges. Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

N supply Fall nitrogen accounting

Pre-plant soil N in Fall soilavailable N Fertilizer irrigation available Plant N Accounted

(0-2') N water N (0-2') recovery N Balance'Treatment lb/acre

Check 68.4 0 8 76.7 87.7 164.4 88.0

Potato sludge 71.0 0 8 104.1 147.6 251.6 172.6

Sludge mix255.7 0 8 167.5 165.4 332.9 269.2

N fertilizer 53.8 200 8 82.8 165.8 248.6 -13.2

LSD (0.05) 13.5 31.0 24.0 34.9 32.5

'based on the difference between all N supplies and fall N accounting.

2Potato/onion sludge mix (44%/56%).

28

NITROGEN MINERALIZATION FROM POTATO SLUDGEAND ONION SLUDGE

Lynn JensenOregon State University

Malheur County Extension ServiceOntario, Oregon 1997

Introduction

Potato sludge is a by-product of the potato processing industry. While some of thepotato waste has excellent feed value for livestock, the feed value of sludge is too lowto be economical to feed. Onion sludge is generated as a by-product from thedistillation of oil from onions. Both potato sludge and onion sludge are generated inlarge amounts and disposal can be a problem. A practical solution is to use thesematerials as organic fertilizer. Since growers need to monitor the amount of fertilizerthey apply to maintain crop quality as well as to protect the environment, it is importantto be able to predict the amount of nitrogen that will be released from these materials.With knowledge of nitrogen release, sludge can be utilized properly as organic fertilizer.


On April 7th, 100 lbs. of silt loam soil was collected from the Malheur ExperimentStation and thoroughly blended in a portable cement mixer. Check samples of about0.5 lbs. each were collected, then the remaining soil was split into two parts. One partwas mixed with potato sludge at a rate of 1:80 sludge to soil ratio by weight toapproximate a sludge soil application rate of 25 ton/acre and 1:40 sludge-to-soil ratio toapproximate a sludge application rate of 50 ton/acre. The onion sludge was applied atratios of 1:25 and 1:12.5 to approximate soil application rates of 80 and 160 ton/acrerespectively.

Each of the treatments were bagged in plastic bags containing about 0.5 lbs. each, withenough bags for four replications for each of the months of April, May, June, July,August and September. The April bags were analyzed for nitrate and ammoniumnitrogen, the other bags were buried in the soil to a depth of six inches in an onion fieldwhere the samples could be under field conditions. On the seventh of each month, fourreplications of each treatment were dug up and analyzed for nitrate and ammoniumnitrogen content. The analysis was performed by Western Laboratories in Parma. Theonion sludge contained about five percent solids, and was difficult to mix. There was atendency for the soil to roll into small balls and not blend evenly. The difficulty ofblending properly plus the high moisture content may have affected the results of theonion sludge treatments.

29


The potato sludge mineralized similarly to previous years, with the higher sludge ratereleasing the higher amount of nitrogen. The highest rate of increase of mineralizednitrogen for the potato sludge was between August 7th and September 7th. Almosttwice the amount of nitrogen was released from the 50 ton /acre sludge rate ascompared to the 25 ton /acre rate with 29.7 ppm and 53.5 ppm nitrate plus ammoniumnitrogen. The onion sludge mineralization was less than or only equal to the check soilmineralization rate for most of the season. This could be due to the higher moisturecontent of the onion sludge bags compared to the potato sludge bags. The onionsludge bags may have been under anaerobic conditions not suitable for propermineralization. It is also possible that the microbes decomposing the onion sludge mayhave used excess nitrogen released from the soil to establish a proper carbon/nitrogenratio before decomposition could begin. It is more likely that the excess moisturehindered proper mineralization. Care should be taken to dry the onion sludge beforemixing to obtain more uniform mix with less moisture in the bags. Under fieldapplications, the excess moisture would not be a problem.

Table 1. Amount of mineralized nitrogen (ppm) resulting from various sludge mixturesburied in the soil and analyzed during the growing season as compared to anuntreated soil check, Ontario, Oregon, 1997.

Treatment rate 7 Apr 7 May 7 Jun 7 Jul 7 Aug 7 Sep

ton/acre ppm - -

Check 18.5 16.5 18 29.3 32.8 32.8

Potato Sludge 25 17.5 37.2 25.3 36.8 44 62.5

Potato Sludge 50 15.3 36.5 28.3 44.5 54.8 86.3

Onion Sludge 80 7.2 16.3 25.8 34.5 41.8 43.5

Onion Sludge 160 4.6 12.8 18.3 29.3 35.5 43.5

LSD (0.05) 5.8 NS 7.4 NS 11.4 27.7

NS: not significant

30

7-Sep7-Aug7-May

100o.a. g0---m 80 —

70 -.• 60

50 — -• 40 — -+5

30 —30 — -20

0E 10<• 0

7-Apr 7-Jun 7-Jul

Sample Date

Potato and Onion Sludge Trial - 1997

—0— CHECKPOTATO Sludge. 25 Ton

—A— POTATO Sludge. 50 Ton—ONION Sludge. 80 Ton—0—ONION Sludge. 160 Ton

Figure 1. Trend for nitrogen release from buried bags containing potato and onionsludge, Ontario, Oregon, 1997.

Conclusions

The nontreated soil in the trial released 14.3 ppm nitrate and ammonium nitrogenduring the growing season. This amounts to 47 lb N/acre-ft. of nitrogen. The 25ton/acre rate of potato sludge released an additional 98 lbs. of nitrogen and the 50ton/acre potato sludge rate released 177 lbs. of nitrogen over the non treated soil.Most crops grown in Malheur County require 150-250 pounds of nitrogen per year foradequate yields. Depending on the crop grown it would have taken between 25 and50 ton/acre of potato sludge to give an adequate amount of available nitrogen.

31

PREPLANT INCORPORATED HERBICIDES FOR WEED CONTROL IN FIELD CORN

Corey V. Ransom, Joey Ishida, and Monty SaundersMalheur Experiment Station


Introduction

This one year study evaluated preplant incorporated herbicides for weed control andcrop tolerance in furrow irrigated field corn.

Methods

Registered and experimental herbicides were evaluated for weed control and cropsafety in field corn. The soil was Nyssa silt loam with pH 8.0 and 1.2 percent organicmatter. Plots were 10 by 30 feet. Treatments were applied with a CO2-pressurizedbackpack sprayer delivering 20 gpa at 35 psi and were replicated three times.Treatments were applied to the center 7 feet of each plot and incorporated by a singlepass with a spike-tooth harrow prior to planting on May 13, 1997. The Pioneer 3489field corn was planted at 27,000 seeds/acre in 30-inch rows with a John Deere model71 Flexi Planter. Two of the PPI treatments were followed by postemergenceapplications of Banvel that were applied June 6 to corn averaging 10 inches in height.Corn injury was evaluated May 23 and 30. Weed control was evaluated June 6 and 25.Corn yield was determined October 3 by harvesting corn ears from 20 ft of the twocenter rows of each plot, threshing the ears and recording the dry weight of the grain.Grain yields were adjusted to 12 percent moisture.

Results

No corn injury was visible from herbicide treatments. Redroot pigweed control wassimilar among treatments with Dual II at 1.25 lb ai/acre providing among the lowestcontrol and treatments containing Harness or Banvel providing among the highestcontrol. The addition of isoxaflutole to Harness and Axiom treatments increased controlof common lambsquarters. Isoxaflutole and Axiom applied alone were among the leastactive on barnyardgrass. However, the tank mixture of isoxaflutole with Axiom providedbarnyardgrass control comparable to Dual Harness, Micro-Tech, or Surpass. Allherbicide treatments increased corn yield compared to the control except for Dual II at2.0 lb ai/acre. The reduced yield from Dual II (2.0 lb ai/acre) cannot be explained giventhat the lower rate of Dual II and the same rate of Dual II followed by a postemergencetreatment of Banvel both yielded higher than the control. High pressure from commonlambsquarters may have reduced yields.

32

Table 1. Weed control and corn yield with preplant incorporated herbicides, MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1997.

Treatment Rate TimingWeed control' Corn

Yield2Pigweed Lambsquarters Barnyardgrass

lb ai/acre % bu/acre

Dual ll 2 PPI 82 47 83 176

Frontier 1.17 PPI 72 66 77 203

Harness 1.6 PPI 88 60 80 213

Micro-Tech 2 PPI 92 60 75 199

Surpass 1.6 PPI 87 74 83 205

Isoxaflutole 0.05 PPI 82 68 62 220

Isoxaflutole 0.06 PPI 77 83 58 218

Isoxaflutole + Dual II 0.059 + 1.25 PPI 85 79 85 222

Isoxaflutole + Harness 0.059 + 1.0 PPI 95 83 76 226Dual II 1.25 PPI 63 50 68 210Harness 1 PPI 93 65 73 216Exp 31498A 0.41 PPI 77 77 73 228Exp 31498A 0.55 PPI 87 83 81 215Axiom 0.64 PPI 78 66 65 211Axiom + Isoxaflutole 0.32 + 0.059 PPI 87 85 78 218Dual II + Banvel 2.0 + 0.5 PPI + POST 95 73 75 216Axiom + Banvel 0.64 + 0.5 PPI + POST 97 76 79 211Untreated 0 0 0 164LSD (0.05) 18 15 9 22.6

'Weed control evaluated June 25, 1997.2Corn yield taken October 3, 1997 and adjusted to 12% moisture.

33

ONION VARIETY TRIAL, GRADED OUT OF STORAGE JANUARY 1998

Clinton C. Shock and Joey IshidaMalheur Experiment Station


Summary

This trial compared commercial varieties and experimental lines of yellow, white, andred onions for yield, grade, and storability. Field observations were made for relativematurity and bolting. Yield and grade were determined out of storage in January. Totalyield ranged from 394 to 943 cwt/acre and colossal size onion yield ranged from 0 to430 cwt/acre, depending on variety. Significant differences occurred between varietiesin market grades, bolting, maturity, and decomposition in storage.

Methods

The 1997 trials were conducted on an Owyhee silt loam soil with 1.7 percent organicmatter and a pH of 7.4. The field had previously been planted to wheat. Beforeplowing, 100 lb/acre of P 205 , and 20 lb N/acre were broadcast. The wheat stubble wasshredded and the field deep-chiseled, disked, irrigated, moldboard-plowed, roller-harrowed, and bedded in the fall. At bedding, the field was fumigated with 18 gpa ofC-17 and left until spring without further tillage.

The beds were knocked down March 24. On March 25 the beds were sprayed with 4 lbai/acre of Dacthal banded 11-inch wide along the top, and the Dacthal was incorporatedthe next day with a bed harrow.

Onion seed of 57 varieties was received from 16 companies: American Takii,Aristogene, Asgrow, Bejo, Champion, Crookham, Ferry Morse, Harris Moran, Petoseed,Rio Colorado, Rispens Seed, Scott Seeds, Seedex, Shamrock, Sunseeds, andVilmorin. Seed was planted April 7 and 8 in plots four rows wide and 27 feet long. Theonions were planted on 22-inch single-row beds into relatively dry soil. Each varietywas planted with five replications. Seed for each row was prepackaged at the stationusing enough seed for a planting rate of 12 viable seeds per foot of row. Seed wasplanted using four Almaco Cone Seeders mounted on a John Deere Model 71 FlexiPlanter equipped with disc openers.

On April 14, onion rows received 3.7 ounces of 'Lorsban 15G' per 1000 feet of row(0.82 lb ai/acre), the soil surface was rolled, and the first furrow irrigation was started tosupply moisture for seed germination. Because of dry soil, April 14 was the effectiveplanting date. On May 27, alleys 4 ft wide were cut between plots, leaving plots 23 ft

34

long. From May 27 through 30 the seedling onion plants were hand thinned to a plantpopulation of four plants per foot of row (3-inch spacing between individual onionplants, 95,040 plants/acre). On June 3, 90 lb N/acre as urea (197 lb/acre of Urea) wassidedressed using both sides of every row. On June 23, a second sidedress applicationof 90 lb N/acre was applied as urea.

The trial was managed to avoid yield reductions from pests. Weeds were controlledwith cultivations and low-rate herbicide applications as needed until lay-by. Thripswere controlled with four aerial applications of Warrior at 3.8 fluid oz/acre on June 16,June 30, July 24, and August 10. Lannate at 1 quart/acre was added to the Warriorapplication on July 24. Downy mildew occurred in 1997, and was controlled withRidomil MZ 72 at 2.5 lb/acre applied on both July 24 and August 10. Downy mildewcontrol was continued with 2 lb/acre of Dithane on August 16.

The last irrigation of the season was on August 18. Bulb maturity ratings for each plotwere recorded on August 22, 29, and September 5, as visual estimates of percent dryleaf material in each plot, and percent of bulbs with necks collapsed and leaves on theground. Those percentages for each date were averaged for maturity ratings. Boltedonions were counted as the number of bulbs in the 4-row plot on September 10.

The onion bulbs were lifted on September 11 to field-dry. Onions were topped from themiddle two rows of every plot September 23 and 24 and were placed into storageSeptember 26. Onion varieties were compared based on bulb grade out of storage onJanuary 5-7, 1998. Bulbs without blemishes (No. 1s) were graded according to theirdiameter and quality. Size categories were < 21/4 inches in diameter (small), 2 1/4 to3-inch (medium), 3 to 4-inch (jumbo), and 4-inch and larger (colossal). Split bulbs weregraded as No. 2s. Bulbs infected with Botrytis neck rot in the neck or side and bulbsinfected with plate rot were weighed separately out of storage and the percent of losseswere calculated. Variety differences were compared using ANOVA and least significantdifferences at the 5 percent probability level, LSD (0.05).


Onion development was normal in 1997. Bolting per 4-row plot averaged 1.1 boltedonions per plot of approximately 368 onions (Table 1). The worst variety for boltedonions had only 7.6 per plot, or just over two percent.

Varieties are listed by company in alphabetical order and ranked by bulb yield for eachcompany's varieties (Table 1). The LSD (0.05) values at the bottom of Table 1 shouldbe considered when comparisons are made between varieties for yield and grade.Differences equal to or greater than the LSD (0.05) value for a column should existbefore any variety is considered different from any other variety in the categorycompared in that column. Total yield out of storage averaged 676 cwt/acre with a widerange of yield and grade. Total yield out of storage ranged from 394 to 943 cwt/acre

35

and colossal size onion yield ranged from 0 to 430 cwt/acre, depending on variety.Significant varietal differences were recorded in all size classes by variety.

Onions were scored for neck rot with either Botrytis on the side of the bulb or in theneck or scales. Neck rot averaged 5.6 cwt/acre, or 0.8 percent. Black mold was not afactor in the storage of this lot of onions, but plate rot was a factor. Losses to plate rotwere greater than the numbers recorded because onions with this defect usually loosemost of their weight before being graded out of storage.

36

0.70.70.80.10.51.01.91.00.60.11.50.60.80.31.50.52.80.50.30.01.2

0.33.30.96.81.54.11.11.37.73.32.62.21.27.13.60.12.10.61.54.84.5

0.00.40.11.10.20.40.10.21.10.40.40.30.21.10.80.00.30.10.21.00.8

74.310.65.08.91.28.3

24.74.27.0

15.32.0

14.30.03.4

10.081.314.312.113.52.38.7

1.10.92.20.00.00.00.30.61.00.90.72.60.80.73.60.02.93.34.82.44.5

5.83.8

21.753.738.523.528.352.550.643.051.949.553.255.851.4

0.027.320.225.237.548.0

20.821.338.660.551.039.345.856.756.550.155.454.356.658.160.1

3.339.139.641.048.766.1

43.035.259.980.167.351.253.475.866.759.366.766.569.470.380.2

7.453.357.960.865.486.7

0.00.80.00.20.08.06.80.60.02.60.60.00.00.80.00.40.20.00.00.00.0

Table 1. Yield, grade, color, and maturity of experimental and commercial onion varieties grown in 1997 andevaluated in 1998, Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1997.

Seed

Onioncompany variety

American 9003CTakii, Inc. T - 433

407BCondorT - 406

Aristogene SevilleBravoMaritimeEnvoy

Asgrow VegaViperViceroyXPH 15040RegimentFury

Bejo CastilloGladstoneDaytonaAltisimoRedwing

Champion PX 81892

Bulbcolor

yellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowyellowwhiteyellowyellowredred

cwt/acre943.7886.3656.4650.6642.7932.8930.8802.3679.3813.6717.8692.1679.9665.4504.1716.0638.1586.9573.0521.7500.8

861.2868.1642.8634.3636.7911.8887.7788.4659.3792.8701.6668.9673.0652.3479.0631.1600.2568.3551.6512.2477.8

424.2 427.2 9.8 6.6

352.3 534.5 2.0 5.0

162.5 472.8 7.5 5.4

81.6 543.4 9.3 0.6

47.3 582.8 6.5 3.3

395.4 513.7 2.8 8.6

368.9 514.9 3.9 16.9

171.5 612.9 4.0 7.8

80.0 568.9 10.3 4.4

259.2 526.7 6.8 1.3

111.8 580.3 9.5 10.9

136.1 522.8 10.1 4.2

105.1 554.7 13.2 4.9

90.7 552.1 9.6 1.9

24.7 432.5 21.9 8.0

117.0 508.1 6.0 3.5

61.4 524.8 14.0 18.6

29.2 524.3 14.8 2.7

53.6 465.7 32.3 1.6

19.7 477.3 15.2 0.0

32.2 415.5 30.1 5.3

Total Marketable yield by grade Non-marketable yield

Maturity rating Bolters'yield Total >4inch 3-4inch 2 1/4-3inch Neck rot

Plate rot # 2s Small 8/22 8/29 9/5 9/9

cwt/acre cwt/acre % cwt/acre % cwt/acre

Total Marketable yield by gradeyield Total >4inch 3-4inch 2V4-3inch

Non-marketable yield

cwt/acre % cwt/acre % cwt/acre

Onion Bulbvariety color

cwt/acre cwt/acre

Maturity rating Bolters'Neck rot

Plate rot # 2s Small 8/22 8/29 9/5 9/9

810.2688.7582.6797.9754.1460.3433.8895.3838.5715.7669.7654.8632.7545.9860.3818.7802.9717.3

772.7637.7568.7780.2727.7447.0407.8884.0825.6703.6660.1625.3624.1537.2827.0796.9776.4674.9

243.5132.761.7

304.6190.3

1.93.2

430.2276.2146.666.1

102.539.426.5

318.2331.9351.7308.7

522.0494.3467.6469.5531.9406.6361.7450.3544.8548.0584.1512.6569.9494.2504.0456.7417.6362.1

5.5 5.0 0.6

7.2 6.3 0.8

10.7 15.8 2.4

39.5 4.6 0.8

6.0 6.4 0.8

5.5 10.1 1.3

38.5 4.2 0.9

42.9 4.8 1.1

3.4 4.2 0.5

4 .6 5.6 0.7

9.0 6.3 0.9

9.9 1.4 0.2

10.2 11.8 1.7

14.9 0.8 0.1

16.5 0.0 0.0

4.8 8.1 0.9

8.3 13.0 1.6

7.1 9.4 1.1

4.1 18.4 2.7

38.8 53.032.6 49.053.7 71.636.0 53.536.0 53.460.5 91.175.6 94.846.9 53.234.9 53.647.9 55.753.5 70.339.0 55.053.3 63.757.8 73.449.5 55.051.3 58.243.8 55.136.6 50.9

846.0 824.1

265.1 553.6 1.6 0.2 15.1 0.2 38.6 48.3 55.6 0.4

2.81.40.46.62.40.60.22.20.60.00.00.20.00.06.41.02.00.2

3.24.4

3.16.22.81.74.45.53.61.76.01.85.74.64.04.31.61.5

0.40.60.60.90.40.41.00.60.40.20.90.31.00.80.50.50.20.2

26.930.2

3.13.7

12.62.5

12.61.73.72.31.2

15.91.52.3

20.62.9

14.322.0

1.10.63.01.41.04.94.30.00.01.90.90.00.61.80.61.51.20.5

25.715.245.721.221.242.559.041.025.045.745.725.244.554.733.246.728.722.1


Seedcompany

Crookham Sweet yellowPerfectionCelebrity yellowXPH 95345 yellowSueno yellowFMX 2031 yellowFMX 2015 yellowHMX 4633 yellowImpact yellowQuest yellowVision yellowPayette yellowPinnacle yellowApex yellowTeton yellowPX 67691 yellowRNX-10020 yellowRNX-10245 yellowRNX-10161 yellowRNX-10311 yellow

Ferry-Morse

Harris Moran

Petoseed

Rio ColoradoSeeds, Inc.

Seed Onioncompany variety

yield Total >4inch 3-4inch 2Y4-3inch Neck rot Plate rot # 2s Small 8/22 8/29 9/5 9/9Bulbcolor

cwt/acre cwt/acre cwt/acre % cwt/acre % cwt/acre

6.1 5.4 0.6

10.4 15.4 2.2

31.8 1.2 0.2

8.1 5.7 0.7

32.2 1.1 0.2

11.9 2.5 0.4

42.1 0.5 0.1

6.5 5.7 0.7

6.1 0.0 0.0

8.1 3.0 0.5

14.4 0.8 0.1

36.9 0.3 0.1

40.6 1.7 0.4

39.9 7.8 1.9

13.1 1.3 0.2

27.4 0.9 0.2

14.6 5.6 0.8

9.3 8.1 1.2

847.9 827.1

297.4 523.7

734.5 680.5

176.7 493.5

585.2801.6422.4627.3394.7737.5700.0611.0588.9478.1409.0381.5652.1492.2676.4

53.0

566.6749.8415.3573.9383.0727.2695.9602.2584.1443.5393.5356.7586.7456.6651.6

57.3

3.0 0.4 11.7 0.6 27.1 35.2 50.1 5.2

1.9 0.3 36.4 0.3 22.5 37.2 52.0 0.4

1.16.22.41.31.71.12.80.11.46.12.95.92.64.13.1NS

0.20.90.50.20.50.10.40.00.31.30.71.60.40.80.50.8

12.838.6

1.147.0

1.13.50.62.60.8

21.43.45.7

58.922.514.115.1

3.51.22.52.68.50.00.63.21.96.87.55.52.68.02.03.0

28.724.773.249.664.044.043.548.729.848.864.060.037.752.937.710.2

47.341.688.855.373.952.255.853.543.462.582.981.747.159.649.0

9.0

63.254.997.462.294.459.664.671.666.485.093.292.762.477.563.6

6.7

0.00.40.00.00.00.81.40.00.00.00.00.00.00.01.12.3

85.4232.1

7.262.7

0.0155.4122.554.724.5

8.40.05.6

88.26.2

147.779.3

449.5509.7375.8499.3340.9565.3567.3539.4545.2398.2352.9311.2485.4422.9490.5

76.6


Total

Marketable yield by grade Non-marketable yield

Maturity rating Bolters'

Goldstar yellow 871.8 839.2 365.2 468.8

5.2 9.6 1.1 1.1 0.1 22.0 0.0 3.9 15.9 32.7 7.6RispensSeed,Inc. Superstar yellow

Golden yellowSecurityWrangler yellow

Scottseed Great Scott yellowSeedex, Inc. Tenshin yellowShamrock SSC 0377 yellow

VDH 89573 yellowSunseeds Vaquero yellow

Valiant yellowTesoro yellowSabroso yellowMambo redFlamenco redTango red

Vilmorin, Inc. Santos yellowLorenzo yellow

MeanLSD (0.05)

1 Number per 4-row plot, 23 feet long.

EVALUATION OF ONION HARVESTING METHODS 1997

Clinton C. Shock, Monty Saunders, and Ken TeramuraMalheur Experiment Station, Ontario, Oregon

Introduction

Onion growers would like to reduce harvesting costs yet still achieve high quality onionsout of storage. Decay and weight loss from all sources during storage was comparedfor sweet Spanish onions harvested five different ways.

Methods

Vega sweet Spanish onions were planted March 15 on the farm of Ken Teramura,Ontario, Oregon at 4-inch spacing in two double rows on 40-inch beds. The plantingrate was 156,800 seeds/acre and the actual stand achieved was about 80 percent or125,000 plants/acre.

The soil had a cation exchange capacity of 20 meq/100 g and received fall fertilizationof 80 lb N/acre and 100 lb/acre of phosphate as 16-20-00. Spring N fertilizationconsisted of 170 lb N/acre as ammonium nitrate.

Onions were lifted September 8, and the onions were harvested from September 18through 20, 1997.

Treatments were as follows all out of the same field of Vega onions, 6 bins stored pertreatment:

1. Topper/loader Harvest September 19 with a topper loader (Top Air, Parma,ID) to a truck and from there to bins.

2. Topper/windrower. Harvest September 20 with a topper windrower (Top Air,Parma, ID). Onions were loaded with the topper loader to a truck and fromthe truck to bins.

3. Flailer. Top onions September 7 with a flailer (Slyter Flailer, Weiser, ID).Onions were loaded September 19 with the topper loader to a truck and fromthe truck to bins.

4. Hand-topped: Onions were topped by hand September 18 and poureddirectly into bins.

5. Untopped: Onions were placed untopped into topping baskets and poureddirectly into bins on September 18.

40

Harvesting treatments were to have been split between heat-treated to a bulb pulptemperature at 1 cm of 90 °F and non heat-treated. Hot mid-September weatherheat-treated all the onions in the field after lifting, making heat treatment at harvest oflittle additional value. Malheur Experiment Station weather station air temperaturereached 90 to 93 °F on September 8, 9, 10 and 11 after lifting the bulbs and the soiltemperature at 4 -inch depth reached 80 to 82 °F each of these days.

All onions were stored in the same storage at the Malheur Experiment Station. Onionswere graded out of storage on January 7, 8, and 9, 1998. Onions were separated bymechanical injury, Botrytis infection including neck rot, black mold, plate rot, sproutedonions, and healthy onions. The healthy onions were graded into split double onions,and by diameter into small, medium, jumbo (3-4 inches) and colossal sized onions.Onions were rated subjectively for color, top retention, and skin retention out of storage.

Discussion

In the 1997 topping trial, defective onions averaged a moderate 6.4 percent (Table 1).Defective onions averaged 5.5 percent Botrytis gray mold in the onion neck and on theshoulders, but the topping and handling methods did not significantly affect Botrytis inthis trial. Mechanical injuries differed significantly between every treatment, withuntopped onions suffering the least mechanical injury and topper/windrower resulting inthe greatest amount of mechanical injury (Table 1, Figure 1).

Untopped onions had 1.07 percent tops out of storage and less total pack out in termsof weight per bin because there were 13 percent fewer onions in each bin. Untoppedonions held their skins well, had the lowest percent of mechanical injury and a lowamount of black mold. Untopped, hand topped, and topper/loader treatments wereamong the best in percentage of pack out (Table 2).

The topper/loader treatment had only 5.2 percent defective onions (Figure 1) and wasamong the lowest total shrink losses and was among the best in percentage pack out,90.2 percent (Table 2). It would be desirable for growers to be able to reduce harvestcost while retaining onion quality in storage and pack out. One-time-over mechanicalharvest with the topper/loader reduced onion damage without affecting storability ascompared to onions that were windrowed then further cured before loading. This trialcould be repeated over several years for a higher level of confidence in application ofthe experimental results to commercial production.

Over all bins, independent of topping and loading, the percent of loss to black moldtended to occur in the same bins with the highest percent of mechanical injuriesrecorded on different onions. This may be a factor of wider importance to the industry:rough handling and the loss of skins through handling could predispose onions togreater risks of losses from decomposition in storage.

41

109876543210

At pack out, onions from each topping and handling treatment were set aside forsubjective evaluations of color and skin retention (Table 2). Topper/windrower onionsthat were windrowed then loaded appeared lighter in color because less skin wasretained. These onions suffered more damage in the grading process than the othertreatments and were not as attractive a commercial product as the onions in the otherfour treatments.

Figure 1. Percentages of defective or mechanically injured onions after five toppingand handling treatments in the 1997-1998 onion topping trial, LSD (0.05) =2.6 and LSD (0.05) = 0.04 percent respectively. Malheur Experiment Station,Oregon State University, and Teramura Farms, Ontario, Oregon.

Defective Mechanical injury

Top/load Top/windrowFlail and load Hand topTopping and handling

Untopped

42

Table 1. Percentages of infected, defective, or injured onions from five topping andhandling treatments in the 1997-1998 onion topping trial, MalheurExperiment Station, Oregon State University and Teramura Farms, Ontario,Oregon.

Botrytis Plate Black Mechanicalmold rot mold No. 2 Sprouted injury Defective

Treatment c/o

Topper/loader in one 4.4 0.11 0.39 0.01 0.01 0.3 5.2passTopper windrower 6.63 0.09 0.86 0.05 0 1.3 8.9then loaderFlail then loader 6.94 0.01 0.19 0 0 0.2 7.3Hand topped then 4.49 0.03 0.2 0.02 0 0.5 5.2hand loadUntopped then hand 5.12 0.04 0.01 0 0 0.1 5.3loadMean 5.52 0.06 0.33 0.02 0 0.5 6.4LSD (0.05) NS 0.06 0.53 NS NS 0.04 2.6

NS: not significant

Table 2. Total pack out and shrink of onions after five topping and handling treatmentsin the 1997-1998 onion topping trial, Malheur Experiment Station, OregonState University and Teramura Farms, Ontario, Oregon.

Percent by weight Subjective evaluationsTreatment Leaves Total Small Pack Color Skin

shrink onions out retention

cYo 0-5 0-10Topper/loader in one pass 0 9 0.8 90.2 3.5 4Topper windrower thenloader 0 12.8 0.4 86.8 2 3Flail then loader 0 11.2 0.9 87.9 3.5 4Hand topped then handload 0 9 0.9 90.1 4 4.5Untopped then hand load 1.07 10.2 0.7 89.1 4 5Mean NA 10.5 0.7 88.8 NA NALSD (0.05) NA 2.6 0.3 2.5 NA NA

NA: not applicable

43

IRRIGATION MANAGEMENT FOR DRIP-IRRIGATED ONIONS

Clinton C. Shock, Erik B. G. Feibert, and Monty SaundersMalheur Experiment Station


Summary

Onions were submitted to 8 soil water potential treatments using subsurface dripirrigation. Onions were grown on 2 double rows spaced 22 inches apart on 44-inchbeds with a drip tape buried 6 inches deep in the bed center. Soil water potential wasmaintained nearly constant at 5 levels by automated, high frequency irrigations basedon soil water potential measurements at 8-inch depth. The highest total, marketable,and colossal onion yields were achieved with the wettest soil water potential, -10 kPa.Reducing the soil water potential below -20 kPa after July 15 did not decrease storagerot but reduced the yield of colossal onions. Maintenance of soil water potential at -10and -20 kPa required 36 and 27 acre-inches of applied water, respectively. Onionevapotranspiration for 1997 totaled 27 acre-inches from emergence to the lastirrigation.

Introduction

Previous research with furrow irrigated onions at the Malheur Experiment Station hasdemonstrated the sensitivity of onions to small water deficits and the need to maintainsmall negative soil water potentials for optimum yield (Shock et al., 1994). The superiorwater application efficiency with subsurface drip irrigation allows for more preciseirrigation management than with furrow irrigation. With subsurface drip irrigation,onions can be irrigated at different soil water potentials and the soil water potential canbe maintained nearly constant, avoiding the oscillations in soil water common withfurrow or sprinkler irrigation. The objective of this trial was to evaluate the effects ofdifferent soil water potentials on onion yield and quality.

Methods

The trial was conducted on an Owyhee silt loam previously planted to wheat at theMalheur Experiment Station. A soil sample taken from the top foot on March 8, 1995,showed a pH of 7, 1.5% organic matter, 5 ppm nitrate-N, and 7 ppm ammonium-N, 20ppm P, and 1.8 ppm Zn.

The field was ripped twice, plowed, groundhogged twice, fumigated with Telone C-17 at20 gpa and bedded into 22-inch centers in the fall of 1996. Onions (cv. Vision,

44

Petoseed, Payette, ID) were planted in 4 double rows spaced 22 inches apart in44-inch beds on April 16. Onions were planted at 140,000 seeds/acre (4.1inches/seed). Drip tape (Nelson Irrigation Corp., Walla Walla, WA) was laid at thesame time as planting at 6-inch depth between the two double onion rows. The driptape had emitters spaced 12 inches apart and a flow rate of 0.49 gal/minute/100 feet.The trial was irrigated on April 23, April 25, and May 2 with a microsprinkler system(R10 Turbo Rotator, Nelson Irrigation Corp., Walla Walla, WA) in order to enhanceuniform onion emergence. Risers were spaced 25 feet apart and connected to 3flexible polyethylene hoses spaced 30 feet apart. Onions started emerging on May 1.

Irrigation treatments consisted of five soil water potential levels (-10, -20, -30, -50, and-70 kPa), maintained nearly constant during the entire season, and three treatmentswhere the soil water potential was maintained constant at -20 kPa until July 15 and thendecreased to -30, -50, or -70 kPa for the remainder of the season. The soil waterpotential (8-inch depth) was maintained constant by 0.06 acre-inch/acre of waterapplied up to 8 times a day based on soil water potential readings every 3 hours. Theirrigation treatments were started on June 13. The 8 irrigation treatments werereplicated five times and arranged in a randomized complete block design. Plots were2 beds wide and 50 feet long.

Soil water potential was monitored in each plot by five granular matrix sensors ( GMS,Watermark Soil Moisture Sensors Model 200SS, Irrometer Co., Riverside, CA). In eachplot, four GMS were installed at 8-inch depth from the surface of the soil, and one GMSwas installed at the 18-inch depth. All GMS were installed below one of the two oniondouble rows in the plot center. The 200 GMS and two soil temperature sensorsinstalled 8 and 18 inches deep were connected via five multiplexers (AM 410multiplexer, Campbell Scientific, Logan, UT) to a datalogger (CR 10 datalogger,Campbell Scientific, Logan, UT). The datalogger was programmed to read the GMS,read the temperature sensors, calculate the soil water potential at the 8 inch depth ineach plot and, if necessary, irrigate the plots individually, according to the plot'sirrigation criteria. GMS were calibrated to soil water potential (Barnum and Shock,1992). The irrigations were controlled automatically by the datalogger using a controller(SDM CD16AC controller, Campbell Scientific, Logan, UT) connected to solenoidvalves in each plot. The pressure in the drip lines was maintained at 10 psi by pressureregulators in each plot. The amount of water applied to each plot was recorded dailyfrom a water meter installed between the solenoid valve and the drip tape. Irrigationswere terminated on August 29.

Onion evapotranspiration (Eta) was estimated using an AgriMet (U.S. Bureau ofReclamation, Boise, ID) weather station at the Malheur Experiment Station and amodified Penman equation (Wright, 1982). Onion Et c was estimated and recorded fromcrop emergence until the final irrigation.

45

Fertilizer solutions were applied through the drip lines via a venturi injector (Mazzeiinjector Model 1087). Uran at 20 lb N/acre was applied on June 2, June 17, June 23,June 26, and July 11, for a season-long total of 100 lb N/acre. A plant sample wastaken from the field for nutrient analyses on July 14. The plants were washed, the rootswere analyzed for nitrate-N, phosphate-P, K, sulfate-S, and the leaves were analyzedfor micronutrients by Tremblay Consulting ( Jerome, Idaho ).

The field was sprayed before onion emergence with Roundup at 2 quarts/acre on April29 to kill emerging weeds. Post-emergence weed control was obtained by theapplication of Goal at 10 oz/acre (1.9 oz ai/acre), Buctril at 12 oz/ac (4 oz ai/acre), andPoast at 16 oz/ac (2.9 oz ai/acre) on May 30. On August 11 the field was sprayed withWarrior at 3.8 oz/acre, Ridomil MZ at 2.5 lb/acre and Kocide at 1 quart/acre for thripsand downy mildew control. On August 16 the field was sprayed with Malathion at 1quart/acre and Dithane at 2 quarts/acre for thrips and downy mildew control.

The onions were lifted on September 22. On September 25 the onions in the central 40feet of the middle two double rows in each plot were topped, bagged, and placed intostorage. The onions were graded out of storage on December 16. Onion bulbs weregraded according to their diameters: small (<2.25 inches), medium (2.25-3 inches),jumbo (3-4 inches), colossal (4-4.5 inches), and supercolossal (>4.5 inches). Splitbulbs were graded as Number Two's regardless of diameter. Marketable onions out ofstorage were considered to be perfect onions without rot in the medium, jumbo,colossal, and supercolossal size classes. All bulbs from each plot were counted duringgrading to determine the actual plant population.


The microsprinkler system used to germinate the onions resulted in uniformemergence. The average plant population was 105,900 plants/acre. Analysis of onionleaves and roots showed all nutrients analyzed to be within the established sufficiencyrange.

The automated drip irrigation system maintained the soil water potential at 8-inch depthrelatively constant for the -10 kPa and -20 kPa treatments (Fig. 1). The soil waterpotential at 8-inch depth for the -30 kPa, -50 kPa, and -70 kPa treatments oscillatedmore and the oscillations increased with decreasing soil water potential. The soil waterpotential at 20-inch depth generally was close to the soil water potential at 8-inch depth.A failure in the datalogger program in early July resulted in a brief cessation of allirrigations, allowing the soil water potential to decrease briefly for all treatments. Thesoil water potential decreased rapidly with the termination of irrigation on August 29.

The total amount of water applied with the drip irrigation system from May 14 to August29 was 36, 27, 22, 18, and 14 acre-inches/acre for the -10, -20, -30, -50, and -70 kPatreatments, respectively. Onion Etc in 1997 totaled 27 acre-inches, indicating the

46

possibility of deep percolation and nitrate leaching with the -10 kPa treatment. Waterapplications to the -20 kPa treatment tracked Et, during the season (Fig. 2).

The highest total, marketable, and colossal onion yield were achieved with the wettestsoil water potential, - 10 kPa (Fig. 3). Supercolossal onion yields were low in this trialand not responsive to soil water potential level. Supercolossal yields might have beenhigher with lower plant populations.

Reducing the soil water potential level after July 15 below -20 kPa failed to reducestorage rot, but tended to reduce colossal onion yield (Table 1). Storage rot was low inthis trial, averaging 1.6%.

Literature Cited

Barnum, J.M., and C.C. Shock. 1992. Comparison of soil water monitoring equipment ina controlled temperature weighing lysimeter. Agronomy Abstracts, ASA, Madison, WI.p. 318.

Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 1994. Soil water potential criteria foronion irrigation, 1994 trial. Oregon State University Agricultural Experiment Station,Special Report 947: 68-78.

Wright, J.L. 1982. New evapotranspiration crop coefficients. J. Irrig. Drain. Div., ASCE108 (1): 57-74.

Table 1. Effect of reducing the soil water potential late in the season on onion yield andquality for subsurface drip irrigated onions, Malheur Experiment Station,Oregon State University, Ontario, OR, 1997.

Super TotalSoil water potential No. two Rot Medium Jumbo Colossal colossal Marketable yieldEarly After July 15

kPa cwt/acre

-20 -20 35.2 15.9 11.4 477.9 386.2 6.8 882.3 933.3-20 -30 90.9 13.1 13.4 502.4 314.1 0.9 830.9 934.8-20 -50 42.7 20.1 11.2 614.9 267.3 1.9 895.3 958.1-20 -70 46.8 9.0 15.1 543.2 184.7 1.2 744.1 799.9

LSD (0.05) NS NS NS NS 105.3 NS NS NS

47

Figure 1. Soil water potential for drip irrigated onions. Malheur Experiment Station,Oregon State University, Ontario, Oregon, 1997.

-10-20 IF . %, ...os \ ,,....„_ -,‘,„,:,,,1 • - ,4

.. lk N.A. .-- f.--t ,-..: . ./. - • . ..-‘viPi 2.: . • ,.. ,V L .. -: \ 11 ...-- .--.A.■

„.. ,

„...k te, \,-:.\ ■60 1 il" r::-':41.'\ ;N' - 1 '►" ' ‘ — - - • -70-1 1111„ *.‘.; -'-' \\

-80 T...11 1 I‘;1-1Vi

182 200

Day of year

--ct?0_

a).150a)

0

-100 164

0

-40

8-inch218 236 254

-30

48

40

35

30 1-

25I')as 20 I-

.c0

'T 10

-6_

1_• 30

25• 'L-

CD

20

15

243

-20

- - -20/-30

'"''" -20/-50

--- -20/-70

Figure 2. Cumulative water applied to drip irrigated onions. Malheur ExperimentStation, Oregon State University, Ontario, Oregon, 1997.

0163 203 243

Day of year

49

S

a)

Figure 3. Onion yield response to soil water potential at 8-inch depth. MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1997.

1200

- 1000•

• 800

-1 600

- 400

- 200

01200

- 1000•

-1 800•

H 600

-; 400Marketable 0

Y- "E951.6+3.8•X 200P-0.001, R2-0.42

0

600

500

400

300

200

Total yieldY- 1063.5+5.3.XP-0.001, R2-0.59

ColossalY= 479.0+5.1vX 100P=0.001, Ff=0.54

0-80 -70 -60 -50 -40 -30 -20 -10 0

Soil water potential, (kPa)

50

POSTEMERGENCE WEED CONTROL IN ONIONS

Corey V. Ransom and JoeylshidaMalheur Experiment Station

Oregon State UniversityOntario, Oregon, 1997.

Introduction

Trials were conducted to evaluate various herbicide tank mixtures for weed control inonions.

Methods

`Quest' onions were planted May 5 with a spacing of 3.3 inches between plants on22-inch rows. Lorsban was applied over the row at 3.8 oz/1000 ft of row.Postemergence herbicide treatments were first applied to onions in the 1 true leaf stageon May 29. Additional applications were made at approximately 7 day intervals. A totalof four herbicide applications were made. At the time of the first application, weedswere already large with redroot pigweed ranging from 0.5 to, 4 inches tall. Commonlambsquarters were 1 to 4, barnyardgrass 2 to 6, and hairy nightshade 0.5 to 6 inchestall. Treatments were broadcast applied with a backpack sprayer delivering 20 gpa at30 psi. Plots were 7.3 feet wide by 30 feet long and treatments were replicated fourtimes. Weed control was evaluated visually June 7. Weed biomass was determinedJuly 29.

Results

Weed control in general was poor because the weeds were large at the time of the firstherbicide application. Hairy nightshade control was highly variable and few differenceswere apparent among treatments. The addition of Goal, Prowl, Dual, or Frontier toBuctril plus Poast increased barnyardgrass control while the addition of Nortron did not.Common lambsquarters control was similar among treatments with Cobra plus crop oilconcentrate (COC) providing less control than the other treatments. Cobra treatmentsalso caused at least 40 percent injury to onions four days after application. Injurysymptoms included necrosis of the leaves and reduced plant height. None of the othertreatments injured the onions. Redroot pigweed control was poor among all thetreatments. The addition of Prowl or Nortron to Buctril plus Poast provided among thehighest redroot pigweed control, while the addition of Dual or Frontier had no effect onredroot pigweed control. However, redroot pigweed biomass was greater with theBuctril plus Dual combination than with Buctri alone. In addition, the combination ofBuctril with Prism and crop oil had significantly more redroot pigweed biomass than theBuctril plus Poast treatment. Buctril plus Frontier and the Buctril and Prism mixturewithout crop oil also had among the highest redroot pigweed biomass.

51

gm2

.0

0

0

0

0

0

0

0

0

0

Table 1. Weed control on June 7, and weed biomass taken July 29 in onions treatedwith sequential herbicide applications (May 29, June 7, June 14, and June25), Malheur Experiment Station, Oregon State University, Ontario, Oregon,1997.

Treatment' Rate

lb ai/acre

Buctril 0.15

Buctril + Prowl 0.15 + 1.5

Buctril + Goal 0.15 + 0.03

Buctril + Goal 0.15 + 0.03+ Prowl + 1.5

Buctril + Nortron 0.15 + 0.25

Buctril + Dual 0.15 + 2.0

Buctril + Frontier 0.15 + 1.17

Buctril + Prowl 0.15 + 1.5

Weed control

Weed biomass,Pigweed Lambsquarters Barnyardgrass H. nightshade Pigweed Lambsquarters Bamyardgrass H. nightshade

49 86 56 56 28 078 86 70 79 15 064 81 74 69 30 073 85 83 75 11

70 84 58 79 3 036 86 78 65 48 041 8b 71 69 42 059 84 70 73 32

+ Dual + 2.0

Buctril + Norton + 0.15 + 0.25 80 86 78 85Dual + 2.0

Buctril + Goal 0.15 + 0.03 60 85 84 70 32Dual+ + 2.0

Cobra + COC 0.125+ 1% 81 48 33 74Cobra + Prism 0.125 + -0.094 88 76 85 84 8+ COC + 1%

Buctril + Nortron + 0.15 + 0.25 71 85 71 80Prowl + 1.5

Buctril + Prism 0.15 + 0.094 40 85 75 63Buctril + Prism 0.15 + 0.094 46 85 76 51+ COC + 1%

Untreated 0 0 0 0LSD (0.05) 17 10 13 18

0

44

46 0 0

35 5 4 1113 2

'All treatments were applied with Poast at 0.1 lb al/acre unless Prism is specified in the table. Dual, Frontier, and Prowl wereincluded only in the first application. Cobra treatments were also applied only at the first treatment. Sequential treatmentsconsisted of Buctril + Poast and included Goat or Nortron if they were applied initially.

52

THRIPS IDENTIFICATION AND THRIPS CONTROL IN ONIONS

Lynn JensenMalheur County Extension Service


Introduction

There were three objectives to this trial.

1. Identify species make up of thrips populations in onion fields throughout theTreasure Valley during the growing season,

2. Determine the efficacy of new insecticide products on thrips, and3. Evaluate insecticide rotation sequences for control of thrips.

Two species of thrips were identified in commercial onion fields during the 1997growing season. These were the onion thrips (Thrips tabaci) and western flower thrips(Frankliniella occidentalis). These species could respond differently to insecticides so itis important to determine which species are present when evaluating insecticidetreatments.

Because of the number of generations per year, thrips rapidly build up resistance toinsecticides. Rotating between different classes of insecticides is one method ofdelaying the development of resistance.


Thrips were collected at one-month intervals from plants in eleven onion fieldsthroughout the Treasure Valley during the growing season. The thrips were collectedwith an aspirator, placed in vials containing 70% ethyl alcohol and sent to the OSUinsect identification lab in Corvallis. Thrips were identified by species and classified aslarva, nymphs, or adults. The eleven sites were Ontario, Oregon Slope, Brogan,Owyhee Junction, Adrian, Vale, and Nyssa in Oregon and Weiser, Wilder, Roswell, andFruitland in Idaho.

Two similar efficacy trials were initiated, one near Ontario and one near Nyssa. Therewere fourteen treatments in each trial. Thrips counts were made just before treatmentswere applied and at 3, 7, and 14 days after treatment (DAT) at both sites except theNyssa site where the onions were completely defoliated by hail 12 days after treatment.The plots were 2 beds (each 40 inches) wide by 25 feet long. Onions were planted ontwo double rows/bed. The treatments were replicated four times at each location.

53

The treatments were made with a CO2 pressurized plot sprayer set to deliver 51.1 gpa.The center two rows of each plot were evaluated by counting the total number of thripson 15 plants.

Table 1. Application dates and conditions for the Ontario and Nyssa sites, 1997.

Application DataOntario Site Nyssa

Application Date 6/6/97 6/7/97Gallonage 51.1 gpa 51.1 gpaWind Calm CalmAir Temperature 74 F 78 FTime of application 2:30 - 4:30 PM 3:00 - 4:30 PM

The sequence trial consisted of fourteen treatments rotated at two week intervals for asix week period of time. The evaluations were made at 14 days after treatment justprior to the next treatment. Application dates were June 6, June 20, and July 3.


Treasure Valley thrips species identification. Eleven onion fields throughout the Valleywere sampled during June, July, and August to determine the species composition ofthe thrips population. All of the thrips sampled at each location during the 1997 growingseason were identified as onion thrips (Thrips tabaci). No western flower thrips werefound in any of the samples collected. Table 2 shows the breakdown of the samples forlarva, nymphs and adults.

54

Table 2. Onion trips survey results for the Treasure Valley during 1997.

Field location Date Larva Nymphs adults

Ontario June 16 70 14

July 20 68 12

August 15 46 39

Oregon Slope June 0 0 100

July 51 33 16

August 48 43 9

Weiser June 0 0 100

July 27 60 13

August 26 63 11

Brogan June 0 23 77

July 50 45 5

August 20 40 40

Owyhee Junction June 24 47 29July 44 48 8

August 35 41 24

Wilder June 15 70 15July 35 56 9

August 43 41 16

Roswell June 25 35 40July 57 37 6

August 28 53 19

Adrian June 17 66 17July 31 62 7

August 28 65 7

Vale June 17 21 62July 34 46 20

August 32 56 12

Nyssa June 0 15 85July 32 53 15

August 34 46 20

Fruitland June 2 29 71July 20 70 10

August 39 52 9

55

i% larva% nymphs% adults

There was a higher percentage of adults in June than in the succeeding two months.This is because the thrips are moving into the fields as adults during June. The datawould suggest most of the thrips increase in July and August was by reproductionrather than movement from surrounding areas. The average make up of the populationfrom all sites shows high presence of adults in June compared to nymphs and larva(Figure 1).

Figure 1. Average population composition from eleven onion fields in the TreasureValley, 1997.

Efficacy Trial. The efficacy trial contained three rates of Alert, Fipronil and acombination of Fipronil and Warrior. Alert and Fipronil are new compounds not yetregistered for onions, but which have some potential for use. Concep is a naturalpyrethrum extracted from plants. Gardian is a garlic oil extract used to enhance theactivity of insecticides. Orthene is not currently registered on onions, although it isregistered on many other crops. The results of the trial are shown in Table 3 and 4.

56

Table 3. Efficacy of commercial and experimental insecticides on onion thrips, Ontario,Oregon, 1997.

Treatment Formulation a.i. / ac. Rate/ac. Avg. number thrips / 15 plants

- - - - oz/acre - - - -3 daysafter

treatment

7 daysafter

treatment

14 daysafter Average

treatment

1 UTC 8.6 5.2 6.6 6.9

2 Alert 2.0 s.c. 0.2 12.8 oz. 7.2 4.7 10 7.3

3 Alert 2.0 s.c. 0.25 16.0 oz. 5.9 3.9 8.6 6.13

4 Alert 2.0 s.c. 0.35 22.4 oz. 7.4 5.3 8.8 7.17

5 Warrior 2.09 cs 0.03 1.8 oz. 4.8 4.9 4.3 4.67

6 Warrior 1.0 cs 0.03 3.8 oz. 7.4 4.8 6.1 6.1

7 Warrior 1.0 ec 0.03 3.8 oz, 5.5 3.8 5.4 4.9

8 Fipronil 1.67 sc 0.068 5.2 oz. 7.1 5.3 7.7 6.7

9 Concep 64.0 oz. 11.1 6.4 8.1 8.5310 Concep + Warrior 64.0 oz. + 3.8 oz. 6.7 4.8 7.2 6.2311 Gardian + Warrior 32.0 oz. + 3.8 oz. 5.9 4 8.4 6.112 Orthene 75 s 21.25 oz. 6.2 4.5 7.4 6.0313 Fury 1.5 ew 0.0375 3.2 oz. 6.5 5.4 8.7 6.8714 Fipronil + Warrior 1.67 sc + 1.0 ec 5.2 oz. + 3.8 oz. 6.4 4.7 10.3 7.13

LSD (0.05) 2.6 NS. NS.

Table 4. Efficacy of commercial and experimental insecticides on onion thrips, SkeenFarms, Nyssa, Oregon, 1997.

Treatment Formulation Rate Avg. number thrips / 15 plants

lb ai/acre oz/acre3 days aftertreatment

7 days aftertreatment Average

1 UTC 7.3 6.5 6.92 Alert 2.0 s.c. 0.2 12.8 oz. 4.3 3 3.653 Alert 2.0 s.c. 0.25 16.0 oz. 6.2 5.9 6.054 Alert 2.0 s.c. 0.35 22.4 oz. 6 5.6 5.85 Warrior 2.09 cs 0.03 1.8 oz. 6.1 4.6 5.356 Warrior 1.0 cs 0.03 3.8 oz. 4.7 4.5 4.67 Warrior 1.0 ec 0.03 3.8 oz. 4.6 4.4 4.58 Fipronil 1.67 sc 0.068 5.2 oz. 6.4 4.7 5.559 Concep 64.0 oz. 6.6 8.4 7.510 Concep + Warrior 64.0 oz. + 3.8 oz. 4.6 2.9 3.7511 Gardian + Warrior 32.0 oz. + 3.8 oz. 4.8 3.6 4.212 Orthene 75 s 21.25 oz. 4.4 4.5 4.4513 Fury 1.5 ew 0.0375 3.2 oz. 5.4 4.1 4.7514 Fipronil + Warrior 1.67 sc + 1.0 ec 5.2 oz. + 3.8 oz. 4.7 1.2 2.95

LSD (0.05) 1.9 3.2

57

Figure 2. A comparison of Concep and Warrior at two bcations,Ontario and Nyssa, Oregon, 1997.

I Concep - Ontario- Concep-Nyssa- Warrior - Ontario

1-s- Warrior - Nyssa

58

The Ontario insecticide efficacy trial was in the same location as in 1996 when therewere no differences among treatments. In 1997 there were significant differences atthe 3-day counts but not at the 7 and 14 day counts. The Nyssa site had significantdifferences at both the 3 and 7 day counts, but a severe hailstorm destroyed the foliageprior to the 14-day counts.

The pyrethrum Concep gave significantly poorer control than the synthetic pyrethroidWarrior 1.0 e.c. (Figure 2). Garlic oil (Guardian) tended to increase onion thrips controlat the Nyssa site, though not significantly (Figure 3). There was no response to garlicoil at the Ontario site (Figure 4). Orthene gave good thrips control at both locations(Figure 5). Alert and Fipronil both gave variable control but may be useful as rotationalinsecticides if they become labeled for onion use.

Figure 4. A comparison of Warrior and Guardian (garlicoil). Ontario, Oregon, 1997.

Warrior

___EF_Warrior + Guardian

0 3 DAT 7 DAT

Days After Treatment

14 DAT

Figure 5. A comparison of Orthene and Warrior at twolocations, Ontario and Nyssa, Oregon, 1997.

1- - Warrior - Ontario0

^_

Warrior - Nyssa3 DAT 7 DAT 14 DAT ___A_Orthene - Ontario

Days After Treatment ._ Darlene - Nyssa

Figure 3. A comparison of Warrior and Guardian (garlic oil). Nyssa,Oregon, 1997.

.. Warrior--e— Warrior + Guardian

3 DAT 7 DATDays After Treatment

59I

Sequence Trial. The sequence trial did not show any significant differences in 1997(Table 5). The unsprayed check was one of the better treatments in this trial. This issimilar to the unresponsiveness of the treatments in the 1996 year at the same locationand the 7 and14 day counts this year in the insecticide efficacy trial.

Table 5. Onion thrips sequence trial, Ontario, Oregon 1997.

Treatment Date Counted6/19 7/3 7/17 Average

1st application 2nd application 3rd application Avg. number thrips/15 plantsWarrior Warrior Warrior 4.4 9.4 22 11.93Warrior Warrior Lannate 2.6 12.6 20.4 11.87Warrior Lannate Fipronil 2.9 10.2 14.4 9.17Warrior Fipronil Lannate 3.7 13.3 18.2 11.73Warrior Lannate Alert 2.2 9.8 26.2 12.73Warrior Alert Lannate 4.2 12.8 23.4 13.47Orthene Warrior Warrior 2.4 12.6 23.2 12.73Warrior + Garlic Oil Warrior + Garlic Oil Warrior + Garlic Oil 3.8 12.6 20.4 12.27Orthene Warrior Lannate 5.6 13.9 19.1 12.87Orthene Fury + Alert Fury + Alert 4.1 13.2 15.1 10.8Warrior Lannate Lannate 2.6 12 17.7 10.77Warrior Warrior + Lannate Warrior + Lannate 3 11.2 18.1 10.77Check Check Check 2.5 12.7 18.5 11.23Warrior Warrior + Orthene Warrior + Orthene 5.1 10.3 20.8 12.07

Conclusions

All of the thrips sampled in the Treasure Valley in 1997 were onion thrips. Locationswhere insecticide sprays are ineffective in controlling thrips may be due to insecticideresistance of a local thrips population, rather than the presence of different thripsspecies. There is probably considerable resistance to insecticides at the Ontario site.

The synthetic pyrethroid materials (Warrior, Fury) are still among the best treatmentsalthough Orthene, Fipronil, and Alert hold potential

60

STRAW MULCH INCREASES YIELD AND GRADE OF FURROWIRRIGATED ONIONS

Clinton C. Shock, Lynn Jensen, Joe Hobson, Jan Trenkel,Monty Saunders, and Erik B. G. Feibert

Malheur Experiment StationOregon State University

Ontario, Oregon

Summary

Straw mulch has been proven to increase yield and grade of furrow irrigated onions.The purpose of this work was to summarize the results of five different field trials wherestraw mulch was applied to the bottom of the irrigation furrows and to examine thepossible causes of the yield and grade improvements. Furrow mulching with wheatstraw was shown to keep the soil wetter which may benefit the onions. Onions withstraw mulch may have higher populations of predatory insects that could feed on thrips.

Introduction

Straw mulch has been used to reduce erosion and increase water infiltration in MalheurCounty for several years. Manual straw mulching is very laborious and timeconsuming, but there are machines on the market that work very effectively. Strawmulch is applied mechanically to the bottom of the furrow, where it impedes theprogress of the water. By slowing the water, erosion is reduced and the larger wettedarea in the furrow bottom improves infiltration.

Methods

Identification of thrips predators. Onion fields were examined in 1997 for the presenceof predatory insects that could feed on thrips. Sweeps identified the minute pirate bugand lacewing larva. It is not yet known whether these or other predators can controlthrips or if their populations are enhanced by straw mulch.

Preparation of wheat straw. To prepare straw suitable for mechanical application,wheat from a weed free field was cut during wheat harvest with a cylinder typecombine. Wheat straw was cut at 8 to 10 in length, baled, and stored dry. Straw wasapplied to the furrow bottoms prior to the first irrigation, and/or at layby depending onthe field using a mechanical straw applicator ( Hobson Mulching System, HobsonManufacturing Inc., Keiser, Oregon). Our experience indicates that routine onioncultivations are nearly impossible with 800 lb/ac of straw in the irrigation furrows.Splitting the application of straw mulch into two lighter applications allowed for earlyseason cultivation. The early season cultivation is important for weed control.

61

Onion yield and grade in three commercial fields. Mechanically applied straw wastested in replicated plots in three commercial onion fields with typical quarter mileirrigation runs. Soils were silt loam with 4, 1, and 1.5 percent slope respectively in1988, 1990, and 1991. Wheat straw was prepared as described above and applied at730 kg ha -1 in a single operation using a mechanical straw, applicator after laybycultivations and herbicides each year. In, commercial fields, furrows used for irrigationboth have and lack a history of wheel-traffic compaction. Consequently straw wasapplied both to wheel-traffic furrows and to nonwheel-traffic furrows. Onion yield andgrade were observed from 10, 4, and 10 replicates in the three trials respectively. Atharvest, onions were harvested separately from along wheel-traffic furrows andnonwheel-traffic furrows with and without mechanically applied straw. Onions weregraded by size and defects.

Onion yield and grade at the Malheur Experiment Station. Two experiments wereconducted at the Malheur Experiment Station on a Nyssa silt loam with a 3 percentslope. The straw mulch was applied as split applications before the first irrigation andat layby totaling 800 lb/ac in 1991 and as a single layby application of 563 lb/acre in1995. In both of the trials at the Malheur Experiment Station, water inflow, outflow, andsediment loss was measured in furrows with and without straw mulch. Soil waterpotential was measured with Watermark Soil Moisture Sensors (Irrometer Company,Inc., Riverside, CA) and the amount of infiltration was calculated. Onion yields wereevaluated and onions were graded by size and defects out of storage.

Results

Mechanically applied straw at layby increased yields of onions in commercial fields intwo of three years. Furrow mulching increased onion yield and grade significantlyabove the check treatment both years at the experiment station (Tables 1 and 2).Costs of straw application were much lower than the value of the increased onion yieldsin these fields.

Causes of increased onion yield with straw mulch. Straw mulching increased waterinfiltration and the soil remained wetter when the furrows were mulched with straw.Onion yield and grade are known to respond sensitively to soil water potential, so theincreased onion yields probably were due to increased soil moisture. Straw mulchaffects factors other than soil water. Since runoff was reduced, less sediment andnutrients were lost from the field. Thrips pressure was low in these fields. Theunproven possibility exists of decreasing thrips populations through enhanced thripspredators with the application of straw. Straw mulch also can moderate soiltemperature, improving the soil environment for root growth.

62

Conclusions

Furrow mulching was associated with a large increase in total yield, a largeimprovement in onion grade, and occasionally a modest increase in decomposition incomparison to the onions grown without furrow mulching. The increases in yield andgrade were due to onions attaining larger diameters.

Table 1. Market grade and total yield of onions with and without furrow mulching in afield with three percent slope, Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1991.

Erosion control Yield by market gradetreatment Small Medium2 Jumbo Colossal Total Total

<2 1 /2 in 1 /4 - 3 in 3-4 in > 4 in marketable yield

cwt/acreNone 26 218 122 10 350 376Strawed 13 179 345 80 604 617LSD (0.05) 4 NS 39 19 65 59

Table 2. Response of onion yield and grade after storage to furrow mulching to reduceerosion in a field with three percent slope, Malheur Experiment Station,Oregon State University, Ontario, Oregon, 1995.

Erosion Yield by market gradecontrol Number Small Medium Jumbo Colossal Total Total

treatment Rot 2 <2 1 /4 in 2 1 /4 - 3 in 3 - 4 in > 4 in marketable yield cwt/acre

None 8.3 0.2 45.3 154.8 160.9 0.1 315.8 369.6Strawed 73.1 17.1 14.2 69.2 491.7 38.3 599.2 703.6LSD (0.05) 44.3 9.3 10.8 28.3 55.8 11.8 68.5 55.4

63

IRRIGATION MANAGEMENT FOR HYBRID POPLAR PRODUCTION

Clint Shock, Erik Feibert, and Monty SaundersMalheur Experiment Station


Summary

Hybrid poplar (cultivar OP-367) was planted in April 1997 at the Malheur ExperimentStation and submitted to six irrigation regimes. Irrigation regimes consisted of acombination of soil water potentials as thresholds for initiating irrigations and ,eaterapplication rates. The irrigation system consisted of microsprinklers installed along thetree row. Wood volume at the end of September 1997 was highest with the wettesttreatment (keeping soil water potential at 8-inch depth wetter than -25 kPa and a totalwater application of 24 acre-inches). Trees in the wettest treatment averaged 9 feet,11 inches in height and produced 2.8 ft 3/ac of wood volume by the end of September,1997.

Introduction

With timber supplies from Pacific Northwest public lands becoming less available,sawmills and timber products companies are searching for alternatives. Hybrid poplarwood has proven to have desirable characteristics for many timber products. Growersin Malheur County have shown interest in growing hybrid poplars for saw logs. Clonetrials in Malheur County have determined that the clone OP-367 (hybrid of Populusdeltoides X Populus nigra) performs well on alkaline soils for at least two years ofgrowth.

Hybrid poplars are known to have growth rates (Larcher, 1969) and transpiration rates(Zelawski, 1973) that are among the highest of temperate deciduous trees, suggestingthat irrigation management is a critical cultural practice. Little research on irrigationmanagement of poplars for saw logs has been done. The objective of this study was totest the effect of different irrigation rates and frequencies on poplar growth to determineoptimum irrigation management practices.

Materials And Methods

The trial was conducted on a Nyssa-Malheur silt loam (bench soil) with 6% slope at theMalheur Experiment Station. The soil has a pH of 8.2 and 0.8% organic matter. Thefield was planted to wheat for the previous two years and before that to alfalfa. Treflanat 1 lb ai/ac was broadcast and incorporated on April 22. The field was marked using atractor and a solid set sprinkler system was installed prior to planting. Hybrid poplarsticks, cultivar OP-367, were planted on April 25, 1997 on a 14 foot by 14 foot spacing.The sprinkler system applied 1.4 inches on the first irrigation immediately after planting.

64

Thereafter the field was irrigated twice weekly at 0.6 inch per irrigation until May 26. Atotal of 6.3 inches of water in 9 applications was applied from April 25 to May 26.

On May 27 the solid set sprinkler system was removed and the field divided into 24plots consisting of 5 trees surrounded by a single row of buffer trees (total plot area:three rows wide and 7 trees long). A microsprinkter system (R-5, Nelson Irrigation,Walla Walla, WA) was installed with the risers placed between trees along the tree rowat 14 foot spacing. The sprinklers had a water application rate of 0.12 inches per hourat 25 PSI and a radius of 14 feet. Each plot had a pressure regulator (25 PSI) and ballvalve allowing independent irrigation. Water application amounts were monitored dailyby water meters in each plot.

Soil water potential (SWP) was measured in each plot by two granular matrix sensors(GMS; Watermark Soil Moisture Sensors model 200SS; Irrometer Co., Riverside, CA) at8-inch depth, two GMS at 20-inch depth, and two at 32-inch depth. The GMS wereinstalled along the middle row in each plot and between the riser and the third tree.The GMS were read at 8:00 A.M. daily starting on June 13, becoming the starting datefor the irrigation treatments. The daily GMS readings were averaged for each plot andover all plots in a treatment for each depth separately.

The 6 irrigation treatments were replicated 4 times and consisted of 3 SWP thresholds(treatments 1,3, and 4) and 3 irrigation rates (treatments 2,5, and 6; Table 1). All plotsin a treatment were irrigated when the treatment average SWP at 8-inch depth reachedthe threshold. Plots were irrigated separately as needed to maintain the plot averageSWP at 8-inch depth below the threshold. Irrigation treatments were terminated onSeptember 29.

Soil water content in the wettest and the two driest treatments (treatments 1, 5, and 6,respectively) was measured with a neutron probe. Two access tubes were installed ineach plot along the middle tree row on each side of the fourth tree between thesprinklers and the tree. Soil water content readings were made twice weekly at thesame depths as the GMS. The neutron probe was calibrated by taking soil samplesand probe readings at 8-inch, 20-inch, and 32-inch depth during installation of theaccess tubes. The soil water content was determined gravimetrically from the soilsamples aA regressed against the neutron probe readings, separately for each soildepth. The regression equation was then used to transform the neutron probe readingsduring the season into inches of water per foot of soil. Coefficients of determination(R2) for the regression equations were 0.89, 0.88, and 0.81 at P= 0.001 for the 8-inch,20-inch, and 32-inch depths, respectively.

The field was kept weed free by rototilling between the tree rows and by hand weedingalong the tree rows. The field was rototilled twice and hand weeded five times duringthe season.

65

The trees were fertilized with 100 lb N/ac, 44 lb P/ac (100 lb P 205/ac), and 10 lb Zn/acas a mixture of urea, monoammonium phosphate, and zinc sulfate on June 27. Thefertilizer was applied on the soil surface as a ring around each tree and 2.5 feet awayfrom the trunk. Leaf tissue analyses during the season, consisting of a compositesample of the first fully developed leaf from each of the 5 middle trees in the middle rowof all plots in the wettest treatment were used to monitor and correct nutrientdeficiencies. Trees in the wettest treatment might have the most vigorous growth andthe greatest nutrient leaching so they would be expected to have the highest nutrientdemand.

The heights and diameters at 8 inch height of the central 5 trees in the middle row ineach plot were measured at the end of June, August and September. Diameter atbreast height (4.5 ft from ground) was also measured at the end of August andSeptember. Wood volumes were calculated for each of the central 5 trees in the middlerow in each plot using an equation developed for poplars that uses tree height anddiameter at breast height (Browne, 1962).

Results And Discussion

The highest wood volume at the end of August was obtained by the wettest treatment(Table 1). By the end of September, the tallest trees and the highest wood volumewere obtained by the two wettest treatments (Treatments 1 and 2).

Since the plots in each treatment were irrigated individually as necessary, the totalwater applied to each plot within a treatment was slightly different. Regression analysisgives a perspective of the response of wood volume to water applied. Wood volumeboth at the end of August and at the end of September showed a strong linearresponse to applied water (Figure 1). The highest wood volume was obtained by 23acre-inches of water applied through the end of August and by 26 acre-inches of waterapplied through the end of September.

The regression analysis suggests that at least 24 acre-inches of water are needed thefirst year for optimum poplar growth. Reducing the irrigation threshold from -25 kPa to-50 kPa reduced the number of irrigations from 21 to 11. Reducing the number ofirrigations would result in a higher water application per irrigation. The feasibility ofreducing irrigation frequencies and increasing application amounts will depend on thesoil type and irrigation system.

On average, 91% of tree height growth occurred by August 31. However, only 69% ofthe growth in diameter at breast height and only 46% of the growth in wood volumeoccurred by August 31, suggesting the importance of irrigation during the month ofSeptember for year of establishment trees. Terminal budset occurred in approximatelymid September. Leaf abscission started by mid to late October with trees becomingcompletely leafless in mid November.

66

The SWP at 8-inch depth remained wetter than the threshold for the treatment irrigatedat -25 kPa and for the treatments irrigated at -50 kPa with 1.2 and 1.56 inches appliedper irrigation (Fig. 2). In the treatments irrigated at -75 kPa or at -50 kPa with less than1.2 inches applied per irrigation, the SWP at 8-inch depth became progressively drierduring the season. Soil water potential at 20-inch depth generally tracked the SWP at8-inch depth for the treatments irrigated at -25 kPa, for the treatments irrigated at -50kPa with 1.2 and 1.56 inches applied per irrigation, and for the treatment irrigated at -75kPa. In the treatments irrigated at -50 kPa with less than 1.2 inches applied perirrigation, the SWP at 20-inch depth became progressively drier during the season. TheSWP at 32-inch depth was little influenced by irrigation management and remainedrelatively constant during the season, with little difference between treatments.

In early June the leaves showed general chlorosis symptoms typical of nitrogendeficiency, indicating the need for fertilization. A nitrogen deficiency would be expectedsince the field previously had two years of unfertilized wheat. The soil sample taken onApril 11 showed only 45 lb/ac of available N in the top foot of soil.

After the June 27 fertilization, the leaf N content was in the excessive range on July 24and September 2, and within the sufficiency range on August 12 (Table 2). Phosphorusand zinc were in the excessive range on all sampling dates. Potassium was deficienton July 24 and then became excessive and sufficient on August 12 and September 2,respectively, suggesting the effectiveness of the July 30 foliar application of potassiumcarbonate (Double OK, Na-Churs Plant Food Co., Marion, OH). Iron was deficient onJuly 24, and August 12, but sufficient on September 2, suggesting that the July 30 foliarapplication of iron chelate (Sprint 330, Ciba-Geigy, Greensboro, NC) did not completelycorrect the deficiency and that the August 14 foliar application of iron sulfate waseffective in raising leaf iron levels. Magnesium levels fell below the sufficient range onAugust 12, and did not respond to the August 14 foliar application of magnesiumsulfate. Leaf analysis in the spring of 1998 will determine if the September 15 groundapplication of magnesium sulfate was effective. Boron was deficient on all samplingdates, suggesting that the August 14 foliar application of boric acid (Borosol 10, PlatteChem. Co., Fremont, NE) did not completely correct the deficiency. Leaf analysis in thespring of 1998 will determine if the September 15 ground application of boric acid waseffective.

Literature cited

Browne, J.E. 1962. Standard cubic-foot volume tables for the commercial tree speciesof British Columbia. British Columbia Forest Service, Forest Surveys and InventoryDivision, Victoria, B.C. 9p.

Larcher, W. 1969. The effect of environmental and physiological variables on thecarbon dioxide exchange of trees. Photosynthetica 3: 167-198.

67

Zelawski, W. 1973. Gas exchange and water relations. pp. 149-165 in S. Bialobok, ed.The poplars-Popu/us L. Vol. 12. Nat. Techn. Info. Serv., U.S. Dept. of Comm.,Springfield, Va.

Table 1. Average tree height and wood volume for first year hybrid poplars submitted tosix irrigation treatments. Malheur Experiment Station, Oregon State University,Ontario, OR, 1997.

Water application Tree height Wood volumeIrrigated when soil per irrigation total b Total August Sept. August Sept.

water potential s number of 31 30 31 30 Treatment reaches irrigations'---- inches ---- ---- feet ---- ft3 /ac

1 25 kPa 0.80 23.9 30 8.85 9.94 1.31 2.822 when trt 3 is irrigated 1.56 19.8 20 8.66 9.7 0.95 2.503 50 kPa 1.20 15.3 18 8.26 9.11 0.80 1.774 75 kPa 1.50 14.4 15 7.33 8.14 0.44 1.075 when trt 3 is irrigated 0.90 12.9 17 7.71 8.47 0.62 1.156 when trt 3 is irrigated 0.60 11.0 17 7.37 7.8 0.43 0.82

LSD (0.05) 2.7 3 0.47 0.62 0.35 0.70aat 0.2 m depth

bfrom June 20 to Sept. 22 (includes 6.3 inches applied in 9 irrigations during tree establishment).'average of 4 replications. Includes 9 irrigations applied during tree establishment).

68

Table 2. Hybrid poplar leaf tissue analyses and nutrients applied. Leaf tissue was acomposite of the first fully developed leaf from each of 5 middle trees from all plotsin the wettest treatment. Malheur Experiment Station, Oregon State University,Ontario, OR, 1997.

Leaf nutrientSufficiency concentrations

range

Nutrients applied*

Soil Foliar July 24 August 12 Sept. 2 June 27d Sept. 15d July 30b Aug. 14C

Nutrient lb/ac N-nitrogen 2.0-3.2 5.72 2.25 3.39 100

P-phosphorus 0.22-0.45 0.61 0.67 0.55 44K-potassium 1.7-3.0 1.46 4.05 2.76 2

S-sulfur 0.22-0.40 0.22 0.4 0.72Ca-calcium 0.60-2.40 0.92 0.92 0.97

Mg-magnesium 0.40-0.80 0.45 0.39 0.34 10 2Na-sodium 0.01-0.02 0.02 0.02 0.02 ppm

Zn-zinc 25-55 69 109 81 10Mn-manganese 60-175 106 76 137

Cu-copper 6-30 5 13 9Fe-iron 125-350 93 116 284 0.2 0.2B-boron 30-65 27 23 19 0.2 0.1

aJune 27: urea, NH 4 H 2 PO4, and ZnSO4 applied to ground around tree, 2.5 ft from trunk.'July 30: K2CO3 , and Fe chelate* foliar sprayed at 30 gal/ac.cAugust 14: MgSO 4 , FeSO4 , and boric acid* foliar sprayed at 30 gal/ac.dSept. 15: MgSO 4 applied to ground around tree, 2.5 ft from trunk. Boric acid injected in sprinkler syst.*see text for trade names

69

• ••••

••• •

15 25205 10

September 30 •

Figure 1. First year poplar wood volume response to total water applied. MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1997. Each datapoint is the average of 5 trees.

2.0August 31 •

1.5 Y- -0.31+.076•X, R 2 0.67, P=0.001

•

1.0 h

0.5

0.00

O 4

D-0.93+0.16■X, 14= 0.75, P=0.0016

•

•

0 5 10 15 20 25 30

Water applied, (acre-inch/ac)

•

•• •

••

••

70

8-inch

-100

CI_zy..„

-25

o -50 IL -a_

a)-75

-100Oci)

-25

-50 kPa, 1.2 inch

Figure 2. Soil water pOtential at 3 depths in a poplar stand submitted to 6 irrigationtreatments. Malheur Experiment Station, Oregon State University, Ontario, OR,1997.

Day of year

71

GROUNDCOVERS FOR HYBRID POPLAR ESTABLISHMENT

Erik B. G. Feibert, Clinton C. Shock, and Monty SaundersMalheur Experiment Station


Summary

Hybrid poplar (Populus deltoides x P. nigra, cultivar 'OP-367') was planted in April 1997at the Malheur Experiment Station and grown with five groundcovers. Groundcovertreatments consisted of 1) bare ground maintained with a preplant herbicide andcultivations, 2) mowed weed cover, 3) alfalfa between tree rows, 4) wheat between treerows, and 5) squash grown along the tree rows. The field was irrigated uniformly usingmicrosprinklers along the tree row. Wood volume at the end of September 1997 washighest for the bare ground treatment and lowest for the mowed, alfalfa, and wheattreatments.

Introduction

With timber supplies from public lands in the Pacific Northwest becoming less available,economic opportunities may exist for alternatives. Hybrid poplar wood has proven tohave desirable characteristics for many timber products. Growers in Malheur Countyhave shown interest in growing hybrid poplars for saw logs. Clone trials in MalheurCounty have determined that the clone OP-367 (hybrid of Populus deltoides X P. nigra)performs well on alkaline soils for at least two years of growth.

Groundcover management could have a major influence on establishment cost and treegrowth during the first few years before full canopy closure. Ideally, a groundcovershould provide optimum tree growth with the least management cost. Studies withplantation forests (Nambiar and Sands, 1993) and orchards (Hogue and Neilsen, 1987)have shown the negative effect of cover crops and weeds on tree growth, specially inthe first few years. Poplar root systems have a large horizontal spread, and one yearold trees can have a horizontal root spread of up to 9 feet (Friend et al., 1991). Poplarroot systems can also be concentrated on the surface soil. A study of the root systemsof five 4-year-old hybrid poplar clones found that on average 61 percent of the total rootmass was located in the upper 1.2 feet of soil (Heilman et al., 1994). Since poplar rootsystems have a large horizontal and superficial spread, tree growth should be verysensitive to the amount of weed-free area around the tree. The use of intercroppingwould be of benefit where a financial return was achieved during the plantationestablishment without a reduction in tree growth. This study examined five groundcoveroptions and their effect on first-year tree growth.

72


The trial was conducted on a Nyssa-Malheur silt loam (bench soil) with 6% slope at theMalheur Experiment Station. The soil has a pH of 8.2 and 0.8% organic matter. Thefield was planted to wheat for the previous two years and before that to alfalfa. Thefield was marked for planting by a tractor and a solid set sprinkler system was installedprior to planting. Hybrid poplar sticks, cultivar OP-367, were planted on April 25, 1997on a 14 foot by 14 foot spacing. The sprinkler system applied 1.4 acre-inch/acre on thefirst irrigation immediately after planting. Thereafter the field was irrigated twice weeklyat 0.6 acre-inch/acre per irrigation until May 26.

On May 27 the solid-set sprinkler system was removed and a microsprinkler system(R-5, Nelson Irrigation, Walla Walla, WA) was installed with the risers placed betweentrees along the tree row at 14 foot spacing. The microsprinklers had a water applicationrate of 0.12 inches per hour and a radius of 14 feet.

The experimental design was a randomized complete block with four replicates. Theplots were three rows wide and 7 trees long. The five floor management systems wereestablished and maintained as follows:

Bare soil: Treflan at 1 lb ai/acre was broadcast and incorporated on April 22. The plotswere kept weed free by three rototilling operations and five hand weeding operations.Each hand weeding took approximately one man-day/acre.

Mowed: The ground between tree rows was mowed with a sickle bar mower 7 times tokeep weeds below 6 inches in height. The ground along the tree row was handweeded 5 times to maintain a 2-3 foot wide weed free strip.

Alfalfa: Alfalfa seed (cv. Vernema) was broadcast at 20 lb/acre and incorporated with abed harrow and roller on April 22. Goal at 2 lb ai/acre was applied in a 2-3 foot wideband along the tree row immediately after planting. The alfalfa was harvested asforage three times during the season. The ground along the tree row was handweeded 3 times to maintain a 2-3 foot wide weed-free strip.

Wheat: Wheat seed was drilled on April 22. Goal at 2 lb ai/acre was applied in a 2-3foot wide band along the tree row immediately after planting. The wheat was mowedwith a sickle bar mower at the heading stage on June 17. Thereafter the groundbetween tree rows was mowed as necessary to keep weed growth lower than 6 inches.The ground along the tree row was hand weeded 3 times to maintain a 2-3 foot wideweed-free strip.

Squash: Ten winter squash seeds (cv. Honey Boat) were planted every 2.5 feet alongthe tree row on May 28. The ground between tree rows was rototilled twice to maintaina weed-free condition using a PTO driven rototiller before vine growth prevented traffic

73

between the tree rows. By July 11 the squash vines had started to grow up the treetrunks and had to be pulled away. The ground along the tree row was hand weededonce. The squash was harvested October 7.

Soil water potential (SWP) was measured in each plot by two granular matrix sensors(GMS; Watermark Soil Moisture Sensors model 200SS; Irrometer Co., Riverside, CA) at8-inch depth. The GMS were installed along the middle row in each plot and betweenthe riser and the th i rd tree. The GMS were read at 8 A.M. daily starting on June 19.The field was irrigated when the average reading of all sensors reached -50 kPa.

The trees were fertilized on June 27 with 100 lb N/acre, 100 lb P 205/acre, and 10 lbZn/acre as a mixture of urea, monoammonium phosphate, and zinc sulfate. Thefertilizer was applied on the surface in a ring around each tree and 2.5 feet away fromthe trunk.

Leaf tissue samples consisting of the first fully developed leaf in the adjacent poplarirrigation study were taken on July 24, August 11, and September 2 then analyzed fornutrients. Based on the leaf analyses, the trees were sprayed on July 30 with Fe at 0.2lb/acre and K at 2 lb/acre; and on August 14 with Fe at 0.2 lb/acre, Mg at 2 lb/acre, andB at 0.1 lb/acre. Magnesium at 10 lb/acre as MgSO 4 was applied to the ground aroundeach tree on September 15 using the same method as described in the previousparagraph. Boron at 0.2 lb/acre was injected into the sprinkler system on September10.

The heights and diameters at 8-inch height of the central 5 trees in the middle row ineach plot were measured at the end of June, August, and September. Diameter atbreast height (4.5 ft from ground) was also measured at the end of August andSeptember. Wood volumes were calculated for each of the central 5 trees in the middlerow in each plot using an equation developed for poplars that uses tree height anddiameter at breast height (Browne, 1962).


Tree height at the end of August and wood volume at the end of August and at the endof September were highest for the bare-soil plots and lowest for the mowed, alfalfa, andwheat plots (Table 1). Tree height at the end of September was highest for the baresoil or the squash cover crop. The amount of weed-free area was largest in thecultivated plots (100%), less in the squash plots (40%) and the least in the mowed,alfalfa, and wheat plots (20%). The wood volume at the end of September decreasedwith the treatments in the same order as the decrease in weed-free area, in accordancewith research in orchards (Hogue and Neilsen, 1987) and plantation forests (Nambiarand Sands, 1993) .

74

Soil water potential at 8-inch depth was higher during the season in the bare-soil plotsthan in the other treatments (Figure 1). The season-long average SWP at 8-inch depthwas -21, -36, -27, -27, and - 54 kPa for the bare soil, mowed, alfalfa, wheat and squashtreatment, respectively. The SWP data suggest a lower evapotranspiration for the baresoil treatment than for the other treatments. The spray pattern of the microsprinklers inthe squash plots was partly blocked by the vines, resulting in disuniform wetting of thesoil surface.

The trees in the alfalfa and wheat plots showed injury symptoms early in the seasonfrom the Goal application, expressed as necrotic leaf margins and spots in the initialleaf flush. There was no difference in wood volume between alfalfa and wheat plotsand the mowed plots, suggesting that the Goal injury might not have caused asignificant reduction in tree growth. The 2-3 foot wide band along the tree row thatreceived the Goal application in the alfalfa and wheat plots had less weed growth thanthe other plots and remained free of cover crop growth. Alfalfa yield averaged a total of1.97 tons/acre (dry weight based on the whole area between tree rows) from the threeharvests.

Squash yield averaged 6897 lb/acre based on the whole area between tree rows.

These results suggest that in the Treasure Valley, for first year establishment of poplarplantations, the optimum ground management strategy is bare ground withoutconsideration of the economic value of cover crops. Cover crops should be of morebenefit in orchards where weed growth is not precluded by canopy closure and inregions of high rainfall where erosion is a concern. In poplar plantations canopyclosure may preclude any significant weed growth by the third year. The microsprinklersystem used in this study had a low enough water application rate to avoid runoff anderosion, even with the 6% slope.

Literature cited

Browne, J.E. 1962. Standard cubic-foot volume tables for the commercial tree speciesof British Columbia. British Columbia Forest Service, Forest Surveys and InventoryDivision, Victoria, B.C. 9p.

Friend, A.L., G. Scarascia-Mugnozza, J.G. Isebrands, and P.E. Heilman. 1991.Quantification of two-year-old hybrid poplar root systems: morphology, biomass, and14C distribution. Tree Physiology 8:109-119.

Heilman, P.E., G. Ekuan, and D. Fogle. 1994 Above- and below-ground biomass andfine roots of 4-year-old hybrids of Populus trichocarpa X Populus deltoides andparental species in short-rotation culture. Can. J. For. Res. 24:1186-1192.

75

Hogue, E.J. and G.H. Neilsen. 1987. Orchard floor vegetation management. Hort. Rev.9:377-430.

Nambiar, E.K.S., and R. Sands. 1993. Competition for water and nutrients in forests.Can. J. For. Res. 23:1955-1968.

Table 1. Hybrid poplar growth in response to five groundcovers, Malheur ExperimentStation, Oregon State University, Ontario, Oregon, 1997.

Floormanagement

Tree height Wood volume

August 31 September 30 August 31 September 30---- feet ---- ft3/ac

Bare soil 8.83 9.80 1.03 2.69Mowed 6.27 7.60 0.26 0.76Alfalfa 5.36 6.72 0.17 0.63Wheat 6.36 7.70 0.28 0.90Squash 7.55 9.04 0.62 1.52LSD (0.05) 0.87 0.95 0.20 0.49

76

-100170 268

-25

-50

-75

-100 0

•••■•

-25

-50

-75

Squash

Day of year

Figure 1. Soil water potential at 8-inch depth for poplar trees with five groundcovers.Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1997.

Day of year

77

WEED CONTROL FOR POPLAR TREE ESTABLISHMENT

Corey V. Ransom, Joey Ishida, and Monty SaundersMalheur Experiment Station


Introduction

Research was conducted at the Malheur Experiment Station to evaluate herbicides forweed control during poplar establishment.

Methods

Poplar trees (Populus deltoides x P. nigra 'OP 367') were planted using sticks 25 to 30cm long spaced 3.5 feet apart in rows 14 feet apart. Treatments were oriented alongthe center of the tree row with four replications. Herbicide treatments were appliedpreplant incorporated (PPI) or preemrgence (PRE) with PRE treatments being sprayedover the top of newly planted sticks in plots that were 14 feet by 28 feet. Treatmentswere applied with a CO 2-pressurized backpack sprayer delivering 20 GPA at 28 psi.Incorporation of PPI treatments was accomplished by a single pass with a fieldcultivator. Tree planting and treatment applications were accomplished May 8. Treeswere watered as needed with sprinkler irrigation. Poplar injury and weed control werevisually evaluated May 30 and June 6. A late rating of weed control was takenFebruary 16, 1998. Poplar height was taken June 6, September 8, and October 28.Poplar diameters at 20 cm and 4.5 ft from ground level were measured September 9and October 28.

Results

Treatments containing Goal injured poplar trees; however, the trees grew out of theGoal injury as the season progressed. Trees treated with Goal were among the tallestand had among the largest diameter because of season long weed control. Injury fromGoal may have resulted from early bud break or from sprinklers splashing the herbicideback onto newly developing leaves. All herbicide treatments reduced the number ofredroot pigweed and barnyardgrass plants. Treflan and Sonalan alone did notadequately control hairy nightshade and common lambsquarters. Commonlambsquarters was the dominant weed at this site. Prowl provided weed control similarto Goal treatments, but control decreased toward the end of the season. Weedcompetition reduced poplar tree height and diameter in plots where weeds were notadequately controlled. Tree height and diameter were increased by application of allherbicides with the greatest tree growth occurring in plots treated with Prowl or Goal. Inthe untreated check plots, competition from weeds resulted in the death of over 75percent of the poplar trees.

78

Table 1. Weed control in OP 367 poplar trees with soil-applied herbicides, MalheurExperiment Station, Oregon State University, Ontario, Oregon, 1997.

Weed density' Overall weed control2

Treatment

Rate Timing Pigweed Lambsquarters H. nightshade Barnyardgrass 5-30-97 6-5-97 2-16-98

lb ai/acre No /ft2 % .

Treflan 1 PPI 0.1 1.1 1.5 0.9 79 68 4

Goal 2 PRE 0 0 0 0 98 100 89

Treflan + Goal 1.0 + 2.0 PPI + PRE 0 0 0 0 98 100 93

Prowl 2 PRE 0 0 0 0 98 98 41

Sonalan 1.5 PRE 0 1.8 1.8 0 75 64 6

Untreated 0.8 6.8 2.1 2.4 0 0 0LSD (0.05) 0.4 1.3 1 1.1 11 10 12

'Weed densities taken June 6, 1997.2Late weed control was evaluated February 16, 1998.

Table 2. Growth and injury of OP 367 poplar trees in response to soil-appliedherbicides, Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1997.

Poplar'Height Diameter Dead

Treatment Rate Timing Injury 6-6-97 10-28-97 20 cm 4.5 ft treeslb ai/acre cY0 --in-- mm cyo

Treflan 1 PPI 0 9.2 6.6 17 9 14Goal 2 PRE 48 6.4 9.3 33 17 4Treflan + Goal 1.0 + 2.0 PPI + PRE 46 5.9 8.5 29 15 4Prowl 2 PRE 0 8.3 8.6 28 15 4Sonalan 1.5 PRE 0 8.5 6.4 17 9 7Untreated 0 8.3 2.2 5 2 76LSD (0.05) 7 2.1 2.4 8 5 21

'Poplar injury taken June 6, 1997. Poplar diameter and mortality recorded on October 28.

79

SOYBEAN RESEARCH AT ONTARIO IN 1997

Erik B. G. Feibert, Clinton C. Shock, and Monty SaundersMalheur Experiment Station


Introduction

Soybean is a potentially valuable new crop for Oregon. Soybean could provide a highquality protein for animal nutrition and oil for human consumption, both of which are inshort supply in the Pacific Northwest. In addition, edible or vegetable soybeans couldbe exported to the Orient and provide a raw material for specialized food products.Soybean would also be a valuable rotation crop because of the soil improving qualitiesof its residues and it's N 2-fixing capability. Because of the high value of irrigated cropstypically grown in the Snake River valley, soybeans may be economically feasible onlyat high yields.

Soybean varieties developed for the midwestern and southern states are notnecessarily well adapted to Oregon because of lower night temperatures, lower relativehumidity, and other climatic differences. Previous research at Ontario has shown that,compared to the commercial cultivars bred for the midwest, plants for Oregon need tohave high tolerance to seed shatter and lodging, reduced plant height, increased seedset, and higher harvest index (ratio of seed to the whole plant). There is also a need toidentify cultivars that will grow and yield well under high seeding rates and narrow rowspacing.

In 1992, 241 single plants were selected from five F 5 lines that were originally bred andselected for adaptation to eastern Oregon. Seed from these selections was plantedand evaluated in 1993. A total of 18 selections were found promising and wereselected for further testing in larger plots in 1994, 1995, and 1996. This reportsummarizes work done in 1997 as part of the continuing breeding and selectionprogram to adapt soybeans to eastern Oregon.

Methods

The 1997 trials were conducted on an Owyhee silt loam previously planted to wheat.The herbicide Dual at 1 lb ai/acre was broadcast preplant and incorporated with a bedharrow on May 9.

The seed of each variety was cleaned of broken seed pieces, and the number of seedswith cracked seed coats was determined. The seeding rate for each variety wasincreased to account for the seeds with cracked seed coats. The seed was treated withApron fungicide. Seed was planted on May 13 at 300,000 seeds/acre in rows 22

80

inches apart. Rhizobium iaponicum soil implant inoculant was applied in the seedfurrow at planting. The field was furrow irrigated on May 14 since there was insufficientmoisture for adequate seed germination. Emergence started on May 19. The crop wasfurrow irrigated as necessary.

Eleven of the single plant selections from 1992 and six older cultivars were planted inreplicated plots four rows wide by 25 feet long in 1996. The experimental design was acomplete randomized block with five replicates. All plots were cut to 23 feet. Twentynine single plant selections made from F 2 lines in 1996 were planted at the same time insingle rows 15 feet long.

Stand counts were taken from 2 m of one of the middle two rows in each plot on June24. Plant height and reproductive stage were measured weekly for each cultivar. Priorto harvest, the cultivars were evaluated for lodging and seed shatter. The middle tworows in each four-row plot and single rows from the single-plant selection plots, wereharvested on October 28 using a Wintersteiger Nurserymaster small plot combine. Thebeans were cleaned, weighed, and oven dried to determine moisture content. Dry beanyields were corrected to 13 percent moisture. Single-plant selections were made; theplant was cut at ground level and threshed in the small plot combine, and the seed wasbagged and labeled individually. Data were analyzed by analysis of variance; meansseparation was determined by the protected least significant difference test.


Plant stand was well below the target of nearly 300,000 plants/acre for all varieties(Table 1). Probably due to imperfect stands, yields ranged from 30 to 55 bu/acre(Table 1). Higher yields would be achievable with plant stands closer to the planneddensity of 300,000 plants/acre and a planting date closer to the ideal of May 7.

All the older cultivars lodged heavily, and some took too long to mature or did not reachadequate harvest maturity for efficient combining. Most of the 1992 single-plantselections reached physiological maturity in 115 days or less, had no lodging, and hadseed sizes large enough for the manufacturing of tofu (< 2,270 seeds/lb).

Over the last four years the new selections not only have demonstrated advantages inearly maturity, low lodging, and favorable seed characteristics, but also have hadaverage yields that have improved over the initial selections (OR-6 and OR-8) and overthe commercial varieties from the midwest (Agassiz, Evans Gnome 85, Lambert, andSibley).

81

Table 1. Performance characteristics of new soybean selections compared toestablished cultivars (Agassiz, Evans Gnome 85, Lambert, and Sibley),Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1997.

Cultivar

Days tomaturity'

Days toharvest

maturity2 Lodging Shatter Height Stand3Yield Seed countdays from emergence 0-104 % cm plants/acre bu/acre seeds/lb

M92-217 112 120 0 0 80 153,528 55.2 2000M92-220 112 120 0 0 85 129,630 54.6 1974Lambert 112 120 6 0 105 137,596 53.5 1934M92-085 100 112 0 0 80 121,664 50.0 2030M92-213 112 120 0 0 100 139,769 49.9 2084M92-350 100 112 0 0 100 137,596 49.9 2168M92-314 112 120 0 0 80 144,114 49.2 1962M92-237 100 112 0 0 70 134,699 48.5 2049Agassiz 112 120 3 0 70 118,767 46.0 1984M92-223 114 n 4 0 110 115,870 45.5 1930M92-330 100 112 0 0 65 138,320 44.7 2195M92-225 100 112 0 0 60 134,699 43.7 2195

OR-6 112 120 3 0 85 133,251 43.6 1985M92-239 112 120 0 0 65 142,665 42.0 2227

Gnome 85 112 120 7 0 100 118,767 41.8 2040OR-8 120 n 8 0 105 132,527 34.2 2055Evans 120 n 8 0 100 127,457 29.9 1972Sibley 120 n 9 0 60 131,803 29.7 1828

LSD (0.05) NS 7.8 1161 Pods yellowing, 50% of leaves yellow. 2 95% of pods brown, stems dry enough to be combined.3 average of counts in 2m of row in each rep.4 0= none, 10= 100 percent lodging. n= never reached harvest maturity.

82

Table 2. Four year average yields of new soybean selections compared to releasedcultivars, Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1997.

Yield 1994 1995 1996 1997 Average

Cultivar bu/acre M92-314 63.2 48.9 57.8 49.2 54.8M92-220 62.0 49.6 46.3 54.6 53.1M92-350 63.6 55.2 43.0 49.9 52.9M92-330 57.8 51.1 55.0 44.8 52.2M92-225 62.8 49.1 51.7 43.7 51.8M92-213 61.2 43.4 52.3 49.9 51.7M92-237 63.1 50.6 42.1 48.5 51.1M92-085 63.3 48.7 41.2 50.0 50.8M92-217 35.7 49.3 48.8 55.2 47.3Lambert 69.6 31.7 29.4 53.6 46.1Agassiz 62.4 36.3 38.6 46.0 45.8M92-223 45.6 55.3 34.5 45.5 45.2M92-239 47.8 42.2 44.4 42.0 44.1

Gnome 85 67.0 32.6 25.3 41.8 41.7OR-8 66.3 34.0 22.1 34.2 39.2OR-6 58.2 28.2 25.3 43.6 38.8Sibley 64.3 24.0 18.4 29.7 34.1Evans 68.6 13.2 14.2 29.9 31.5

LSD (0.05) 7.1 14.1 7.5 7.8

83

'HICKSII' YEWS AS A SUSTAINABLE SOURCE OF ANTICANCER COMPOUNDS

Clinton C. Shock, Erik B. G. Feibert, Angela Hoffman,Abbey Heck, and Amanda KirkMalheur Experiment Station,

Oregon State University, Ontario, Oregon andDepartment of Chemistry and Physics,University of Portland, Portland, Oregon

Introduction

Taxol® is an effective anticancer drug identified in the 1960s. Taxol® is Bristol-MyersSquibb's registered trademark for paclitaxel. Paclitaxel is commonly referred to as'Taxol' in the press and coversation, the term will be used here. Taxol has been refinedfrom the bark of the Pacific yew tree, Taxus brevifolia Nutt. This slow-growing tree isnative to the temperate northwestern United States and adjacent Canada ranging fromsouthern Alaska to northern California and east to Montana. Taxol is also found insmall twigs, roots, and needles of T. brevifolia and several other Taxus species. Anumber of these species, including T. x media 'Hicksii', commercially available fromnurseries, grow faster than the native species and produce useful amounts of Taxol.

Other compounds with a complex ring structure like the one in Taxol, collectively knownas "taxanes", are found in many yew species. Although other taxanes do not generallyhave anticancer activity, the other taxanes may be used for synthesis of Taxol.

Taxanes, like many other secondary plant products, may be synthesized in response toenvironmental or biotic stress. Environmental stresses such as ultraviolet light, heat, ordrought may therefore enhance taxane biosynthesis. Stressful environmentalconditions increase hormones such as abscisic acid (ABA) which affect root growth andplant survival under water-stressed conditions.

Landscape yews thrive in the Snake River plain of eastern Oregon and southwesternIdaho, producing large masses of annual growth. The major objective of this projectwas to study the effects of water stress on the amount of Taxol or other taxanes andABA made by the landscape yew, T. x media 'Hicksii', a cultivar with high Taxol content.Water stress could be monitored and controlled effectively in the dry desert climate atthe Malheur Experiment Station in Ontario, OR. The shrubs could be managedcommercially for repeated harvesting in hedge rows. Shrubs were supplied withcontrolled amounts of water from June through August of 1996 and 1997. The amountof taxanes extracted from the experimental shrubs receiving each of three irrigationtreatments was compared. Soil and plant water potentials and the degree of stomata!closure were compared, and changes in the concentration of ABA were determined.

84


Plant material, soil and irrigation system. Cutting-propagated yew shrubs (Taxus xmedia 'Hicksii' Rehd.), approximately 2 feet tall, were obtained from Zelenka NurseryInc. (Grand Haven, MI). They were planted on May 3, 1996 in an Owyhee silt loam atthe Malheur Experiment Station. The shrubs were planted 4 feet apart in rows 10 feetapart with the idea that they could eventually grow into hedge rows.

Initial soil analysis in the spring of 1996 showed pH 8.0, 2.6 percent organic matter, 6ppm nitrate-N, and 20 ppm ammonium-N. Other soil extractable soil nutrients included924 ppm K, 4920 ppm Ca, 402 ppm Mg, 336 ppm Na, 1.8 ppm Zn, 11.5 ppm Fe, 7.4ppm Mn, 2 ppm Cu, 14 ppm sulfate-S, and 0.7 ppm borate-B. The field received abanded fertilizer mix on June 17, 1996, consisting of 100 lb N/acre as urea, 100 lbP205/acre as triple superphosphate, 100 lb S/acre as elemental sulfur, and 1 lb Zn/acreas zinc sulfate.

The shrubs were irrigated uniformly for two months after planting using furrow irrigation,after which they were subjected to one of three irrigation rates using drip irrigation.Starting July 15, 1996, one drip tape (Turbulent Twin Flow, Chapin Watermatics,Watertown, NY) was used along each row to irrigate the shrubs. The drip tape hademitters spaced one foot apart and a flow rate of 0.5 gpm/100 ft of tape at 10 psi waterpressure. The irrigation treatment rates were 1.1 acre-inch/acre (minimally stressed,full rate), 0.77 acre-inch/acre (moderately stressed, 70 percent of 1.1 acre-inch/acre),and 0.44 acre-inch/acre (stressed, 40 percent of 1.1 acre-inch/acre) of water wasapplied at each irrigation. The water application rate was calculated based on a3.3-foot wide bed for each shrub row. Irrigation rates were applied to plots one rowwide and five shrubs long arranged in a complete randomized block design with fourreplicates each. Total applied water was measured for each irrigation treatment usingwater meters.

Soil water potential. All plots were irrigated when the average soil water potential(SWP) at a 8-inch depth in the minimally stressed plots reached -40 kPa in 1996 and-60 kPa in 1997. Two granular matrix sensors (GMS, Watermark Soil Moisture SensorModel 200SS, Irrometer Co., Riverside, CA) were installed at a 8-inch depth in line withthe shrubs in each plot. The GMS were previously calibrated to measure SWP. AllGMS were connected via multiplexers (AM 410 multiplexer, Campbell Scientific, Logan,UT) to a datalogger (CR 10 datalogger, Campbell Scientific, Logan, UT. The SWP wasrecorded daily at 8 AM from July 18 to August 28 in 1996 and from June 3 to August 28in 1997.

The shrubs were irrigated according to the treatment criteria on July 15, August 8, andAugust 22, 1996, and on June 25, July 11, July 28, August 9, and August 24, 1997.Based on 3.3-feet wide beds, a total of 5.27, 4.28, and 3.32 acre-inch/acre in 1996, and9.37, 7.58, and 6.08 acre-inch/acre in 1997 were applied to the 1.1, 0.77 and 0.44acre-inch/acre treatments, respectively. These amounts of water include 2

85

acre-inch/acre applied to all treatments after the last sampling date each year and 2acre-inch/acre applied uniformly during May 1997.

Ha/vesting methods and schedules. A sample handling procedure was needed thatwould stop biosynthesis and degradation of taxanes and ABA at harvest. To determinehow to handle harvested samples, six composite samples were randomly taken fromplants in each of the plots on June 30, 1996, placed in 72 plastic zipper bags andassigned to one of three treatments: oven dried at 100 °F or storage in coolers witheither liquid nitrogen or dry ice.

Each summer, twigs with leaves and stems (6 to 8-cm lengths) were taken from eachplot individually before the onset of stress and approximately every three weeks duringthe remainder of the irrigation season. Samples were taken from each of the middlethree shrubs in each plot of five shrubs four times during the summer of 1996 and sixtimes during the summer of 1997. All samples were frozen immediately andtransported overnight on dry ice to the University of Portland for analysis. If notanalyzed upon arrival, they were stored at -80 °C.

Soil water potential and stomata! closure. Twigs were sampled each day during anirrigation cycle from July 14 to July 29, 1997, to determine the relationship betweenplant water potential and SWP. Plant water potential was measured using aScholander pressure chamber (PMS Instruments Company, Corvallis, OR). Chamberpressure was recorded at the point at which xylem exudate appeared on the cut end.As the cuttings were collected for plant water potential analysis, the backs of someneedles on shoots of the same plants were painted with clear fingernail polish. Theseshoots were immediately cut and packed on dry ice and sent to the University ofPortland. Upon arrival in Portland, the polish was peeled off and prepared for viewingwith a light microscope. The polish bears the imprint of the stomata.

Taxol and abscisic acid determination. Taxol and other taxanes were analyzed asdescribed by Hoffman et al. (1996).


Establishment of handling procedures. Three protocols were tested to find the mostreliable method for harvesting and transporting samples from Ontario, OR to Portland,OR. Samples stored in liquid nitrogen or on dry ice had higher Taxol content thanthose that were oven dried. Some of the oven-dried cuttings yielded little or no Taxol.All subsequent samples were collected and immediately placed in a cooler with dry iceand transported overnight in the cooler for analysis at the University of Portland.

Responses to water stress. Tissue samples were harvested and analyzed four timesduring the summer of 1996 and six times during the summer of 1997. The sampleswere generally taken just before irrigation when SWP was lowest and moisture stresswas highest. There were several important differences between the field conditions in1996 and 1997. First of all, the plants had better established root systems in 1997, sothe data were probably more reliable and consistent. Secondly, the SWP that was set

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as an irrigation criterion in 1997 was -60 kPa, drier than the -40 kPa used in 1996, theyear of shrub establishment. There was a greater difference between SWP in stressedand minimally stressed plots in 1997. This difference was apparently large enough toeffect changes in plant ABA and Taxol content.

During the irrigation cycle between July 14 and 28, 1997, both SWP and plant waterpotential were measured and recorded daily. There was a strong positive correlationbetween SWP and plant water potential. Plants with more negative SWP also tendedto have more negative stem (xylem) water potential. This correlation suggests thatmeasurement of SWP may be used to approximate the amount of water stress withinthe plants.

On July 28, 1997, when the samples were harvested for taxane and ABA extraction,needles were also collected for stomata! analysis. Only a few stomata were open onneedles from any of the plants, and none were open on those that were most stressed.Stomata from all the leaves were essentially the same size. The ABA concentrationtended to be higher in shoots from plants grown on plots with more negative SWP.These were also the plants with the fewest open stomata. There were strongcorrelations between ABA concentration, SWP, and the percentage of open stomata.

Taxane and ABA analysis. Taxanes and ABA were extracted and quantifiedperiodically throughout the summers of 1996 and 1997. In 1996, the plants werebeginning to establish themselves in the soil. Differences between the amounts ofTaxol recovered changed throughout the summer. By the end of the experimental time,significantly more Taxol was obtained from moderately water-stressed plots ascompared with the other treatments. The range of Taxol recovery was broad, possiblydue to seasonal and weather differences, plant-to-plant variation, and the fact that rootsystems were still becoming established during the period of treatment.

After the plants were better established, the 1997 irrigation criterion was lowered to -60kPa. There was still variation in the amount of Taxol recovered from the experimentalplots throughout the summer, but the pattern of recovery had changed . The overalltrend for 1997, however, is clear: both the taxanes and ABA concentrations were higherin the stressed plants than in the plants receiving more water.

Strategy for hedge-row yew harvesting for increased Taxol production. To ourknowledge, the present study is the first to relate soil and plant water potential withtaxane recovery from yew. The strong correlation between the Taxol and ABArecovered from yew suggests that either the conditions that increase ABA also increaseTaxol or that when ABA concentrations rise, they may somehow lead to the increase inTaxol. If yew were grown as a crop, it would be important to monitor field conditionsand taxane content so as to determine the best time for harvesting clippings. It is morepractical to routinely monitor the SWP than to measure plant water potential or ABAconcentrations in the tissues.

There is a strong correlation between taxane concentration and SWP treatment. As theSWP decreases, the concentration of Taxol increases. Further studies may be able to

87

fine-tune the timing and amounts of irrigation required to keep the plant growingvigorously and also harvest high yields of Taxol per gram of plant material. A SWP ofabout -70 kPa could be maintained before harvesting. The trees have one growthflush in the spring, and the effects of water stress subsequent to spring growth onsubsequent growth of yew shrubs is not known. The length of time necessary to holdthe plants at water-stressed conditions to induce increased Taxol synthesis is alsounknown.

Conclusion

Taxol® (paclitaxel), an important anticancer agent, is found in many species of yew. Asthe need for Taxol increases, it will be necessary to find sustainable sources for thisdrug. We have shown that T. x media 'Hicksii' shrubs can be grown in the dry climateof Ontario, OR. Hedge-row harvesting of the shrubs may be planned to optimize Taxolproduction by monitoring SWP. Under the conditions described here, the stressedshrubs produce about 50 percent more Taxol than minimally stressed shrubs.Branches could be harvested annually at predetermined conditions through hedge-rowclipping to produce a sustainable supply of Taxol and other taxanes from which Taxolor similar compounds may be synthesized.

Literature Cited

Hoffman, A.M., C.C.J. Voelker, A.T. Franzen, K.S. Shiotani, J.S. Sandhu. 1996.Taxanes exported from Taxus x media Hicksii cuttings into liquid medium over time.Phytochemistry 43:95-98.

88

ASPARAGUS VARIETY PERFORMANCE

Erik B.G. Feibert, Clinton C. Shock, Lamont Saunders, and Greg WillisonMalheur Experiment Station


Introduction

Acreage of asparagus for canning has expanded in the western Treasure Valley since1994. This trial compared the performance of varieties in the Treasure Valley of easternOregon.

Methods

Asparagus crowns of 5 varieties (Table 1) were planted at the Malheur Experiment Stationon an Owyhee silt loam soil on April 7, 1994. The crowns were dipped in a liquid mixture ofBenlate at 1% (v/v) and Captan at 1/2% (v/v) and planted 8 inches apart in trenches 12inches deep and 5 feet apart. Plots were four rows wide and 40 feet long and arranged in arandomized complete block design with 6 replicates. The field was sprinkler irrigated untilthe spears emerged (April 18, 1994); thereafter, furrow irrigation was used. Furrowirrigations were run as necessary on every furrow (every 5 feet). The field was fertilizedwith 50 lb N/acre as broadcast urea in May 1994 and with water-run urea at 15 lb N/acre in1995, and 56 lb N/acre in 1996. The field was hand weeded twice in 1996 to controlvolunteer asparagus. The first harvest season was in 1996. Spears were picked 8 timesfrom April 8 to April 30. The harvest was terminated on April 30 because of declining speardiameter. In 1997 spears were harvested from April 2 to May 5. The field was handweeded twice in 1997 to control volunteer asparagus.

The minimum spear length for harvest was 6 inches measured from ground level to speartip. Spears from the central 20 feet of each of the middle 2 rows in each plot were cut usingasparagus knives then graded immediately. Spears were graded and weighed by class(US Number One and US Number Two) and by diameter 5 inches from the tip (small: lessthan 6/16 inch, medium: 6/16 to 8/16 inch, large: 8/16 to 10/16 inch, mammoth: 10/16-13/16inch, and colossal: 13/16 to 16/16 inch) according to USDA standards for canningasparagus. Spears were graded by class based on straightness and head compactness.Damage by asparagus beetle feeding was not taken into account when grading. Data wereanalyzed by analysis of variance; means separation was determined by the protected leastsignificant difference test.

89


Spears were harvested for 4.5 weeks in 1997. Total yield, over all varieties, averaged2458 lb/acre in 1997, up from 920 lb/acre in 1996 as can be expected from a secondyear of harvest.

Del Monte 361 had the highest yield for grades total US Number One, and MammothUS Number One in 1997 (Table 1). Del Monte 361 was among the highest in USNumber One Large yield. Del Monte 361 had the highest total yield followed by JerseyGiant. Asparagus contracted with American Fine Foods is paid as all US Number Oneif less than 10% of the total is US Number Two. The proportion of US Number Twoyield was low for all varieties (close to 10 percent) and the differences between varietieswere not statistically significant.

Over the two years (1996 and 1997), Del Monte 361 had the highest total yield followedby Jersey Giant and Mary Washington (Table 2). Over the two years, Del Monte 361and Jersey Giant were the highest yielding in US Number One spears. Over the twoyears, Del Monte 361 had the highest yield of US Number One mammoth spears andwas among the highest yielding in US Number One colossal spears.

Volunteer asparagus infestations in the plots with male-only varieties (Jersey Giant andJersey Knight) were almost negligible compared to the other varieties.

In 1996, adults of the asparagus beetle (Crioceris asparagi0 caused extensive feedingdamage to the spears emerging during harvest. The beetle adults were also observedfeeding on the ferns later in the season. One application of rotenone at 0.4 lb ai/acreimmediately after harvest and two applications of Lannate at 0.6 lb ai/acre during theseason in 1996 were used for beetle

90

Table 1. Yield and grade of five asparagus varieties harvested from April 2 to May 5, 1997,from plantings on April 7, 1994. Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon.

US Number One US Number Two

Proportion TotalSmall Medium Large Mammoth Colossal Total Small Medium Large Mammoth Colossal Total of total yield Culls yield

Variety lb/acre --- lb/acre ----

Jersey Giant 182.7 891.4 829.4 275.3 30.8 2,209.5 5.3 58.9 69.5 56.3 4.2 194.3 7.9 85.2 2,489.1

Jersey Knight 96.5 477.1 399.9 139.9 19.7 1,133.2 13.3 57.7 49.9 27.4 0.0 148.4 12.1 61.4 1,342.9

M. Washington 181.9 751.0 641.6 283.0 62.0 1,919.4 15.3 123.9 141.0 43.8 13.2 337.1 13.9 175.5 2,432.0

UC 157 210.4 692.3 582.6 329.9 107.5 1,922.7 19.0 83.6 101.8 47.3 6.6 258.3 10.9 182.2 2,363.1

Del Monte 361 380.6 1,190.6 945.0 477.6 86.1 3,080.1 23.5 129.8 114.1 58.0 14.6 340.1 9.3 241.4 3,661.5

LSD (0.05) 73.1 179.1 178.1 108.4 29.8 397.5 11.5 42.5 53.3 NS NS 104.3 NS 72 478.8

Table 2. Total accumulated yield and grade of five asparagus varieties harvested in 1996and 1997, from plantings on April 7, 1994, Malheur Experiment Station, OregonState University, Ontario, Oregon.

US Number One US Number TwoTotal

Small Medium Large Mammoth Colossal Total Small Medium Large Mammoth Colossal Total Culls yieldVariety

lb/acre

Jersey Giant 350.4 1,413.1 1,137.3 378.3 33.9 3,312.8 15.4 91.6 103.7 61.8 4.2 276.7 229.6 3,819.1

Jersey Knight 178.7 704.1 545.3 188.3 22.2 1,638.7 23.7 80.5 69.9 39.0 2.7 215.8 112.5 1,966.9

M. Washington 363.5 1,096.2 813.9 335.6 64.6 2,673.8 29.6 157.8 159.5 62.0 13.2 422.2 395.5 3,491.5

UC 157 326.3 895.4 631.6 337.8 107.5 2,298.6 29.1 101.6 107.0 47.3 6.6 291.5 335.9 2,925.9

Del Monte 361 543.5 1,541.9 1,083.8 519.0 88.4 3,776.5 50.9 173.0 139.0 65.5 14.6 442.9 465.6 4,685.1

LSD (0.05) 111.8 241.5 210.3 128.9 61.4 557.5 20.0 50.0 NS NS NS 122.3 102.4 672.8

91

VALIDATION AND ADAPTATION OF THE "BLITECAST" MODEL FOR PREDICTINGDEVELOPMENT OF POTATO LATE BLIGHT IN OREGON

Clinton C. Shock and Brad Coen, Malheur Experiment StationLynn Jensen, Malheur County Extension ServiceOregon State University, Ontario, Oregon, 1997

Summary

Seven commercial potato fields were monitored automatically with remote weatherstations during the 1997 season. Temperature and relative humidity in the plantcanopy and rainfall were recorded every 10 minutes and the data was forwarded viacellular phone daily to the Malheur Experiment Station. These data were used toestimate real-time late blight risk, and those estimates were distributed via the stationweb site, e-mail, and 1-800 telephone number. Also weather data from outside of thecrop canopy was collected from the six AgriMet stations closest to the commercialpotato fields with canopy measurements. Data from both monitoring networks wasentered into the "Blitecast" late blight forecasting model. Late blight occurrence wascompared with model predictions.

Late blight was forecast before it occurred in the Treasure Valley. Severity valuesreached 17 at Klamath Falls before late blight was found in Tulelake near KlamathFalls. Late blight occurred in the Willamette Valley before it was forecast based on thesingle station at Woodburn, but if the forecast had been made based on CorvallisAgriMet data, the forecast date would have been May 30. Predictions could beimproved by better selection of microclimates in a growing area most susceptible to thefirst occurrence of late blight. Multiple measurement sites would be preferable to oneeach in both the Willamette Valley and near Tulelake. Late blight was not forecast atMadras in 1997 and was not found. The use of AgriMet data for use in Blitecast needsfurther calibration.

Introduction

Prior to the 1995 growing season, potato late blight (Phytophthora infestans) was not amanagement concern in the Treasure Valley. During the 1995 season, late blightspread rapidly throughout the valley from initial outbreaks in low lying humid areas.Growers made three to six fungicide applications in 1995. Lack of adequate late blightcontrol in 1995 resulted in a loss of yield and a loss of some of the crop during storage.The ability to predict when the disease is most likely to occur and when conditions areconducive to rapid spread would aid in decisions as to the necessity and timing offungicide applications. The refinement of late blight predictions could save growersmoney by improving the efficiency of control measures. Accurate late blight predictions

92

are now needed for areas both where the disease normally occurs and areas such asthe Treasure Valley and Klamath Falls where it has not been known to be a problem inthe past. This study had three objectives:

1. Validate the accuracy of the computer model "Blitecast" in predicting the onset ofpotato late blight in the Pacific Northwest.

2. Automate the "Blitecast" calculations from both weather stations in growers' fieldsand AgriMet stations.

3. Adapt the "Blitecast" model to the relatively arid areas not originally envisioned in thedevelopment of the model. Potato growers are now suffering economic lossesfrom late blight in these arid areas.

Methods

During the 1997 season, weather data (temperature, relative humidity, and rainfall) from13 weather stations (six AgriMet stations and seven remote stations in commercialpotato fields) were forwarded daily by cellular phone to the Malheur Experiment Stationand entered into the "Blitecast" ( a program module that is part of the "Wisdom"software version 1.2 for potato crop and pest management from the University ofWisconsin, Madison, Wisconsin). The model uses the duration of high relative humidityabove 90 percent along with the corresponding range of temperatures to calculate theextent to which the daily environment has been favorable for disease development.The Blitecast program accumulates favorable environmental conditions for late blightwhich are called "severity values". When the "severity value" total reaches 18, lateblight is predicted and fungicide control measures are indicated.

Seven growers' potato fields were monitored automatically in the plant canopy atOntario, Owyhee Jct. (near Nyssa), Woodburn, Klamath Falls, and Madras, Oregon,and at Homedale and Nampa, Idaho, during the 1997 season. Relative humidity,temperature, and rainfall at the plant canopy were recorded by a Campbell data logger(Campbell Scientific, Logan, Utah) every 10 minutes and the data were forwarded viacellular phone daily to the Malheur Experiment Station. These data were used toestimate real time late blight risk, and those estimates were distributed via the stationweb site, e-mail, and 1-800 telephone number. Seven AgriMet stations were monitoredfor temperature, relative humidity, and other parameters every 15 minutes and rainfallevery hour. The AgriMet weather stations used were at Glenn's Ferry, Dry Lake atNampa, the Malheur Experiment Station at Ontario, the Parma Experiment Station,Corvallis, Tulelake, and Madras. An 80 percent relative humidity range was used fromthe AgriMet stations for the duration of risk in the Blitecast program.

Late blight occurrence was compared with model predictions. Here in Oregon, we areapplying Blitecast to regions with hotter and drier summer weather patterns than

93

Wisconsin and Pennsylvania. Some additional factors may be needed to adapt themodel to Pacific Northwest conditions.

Communication of forecasts. The predictions and control recommendations from themodel were updated daily and made available as a recorded message on a telephoneline. Access to the predictions included calls to a 1-(800) number, informationdistribution by regular e-mail letters, and the Malheur Experiment Station home page(http://www.primenet.com/–mesosu/) where late blight risks and treatment informationwere posted regularly.

Results

In 1997 we successfully collected data from seven weather stations in growers' fieldsand six AgriMet weather stations. Examples of the accumulated late blight "severityvalues" are presented in Figures 1 and 2.

The weather stations in the potato canopies in the Treasure Valley developed a rangeof risk estimates (Figure 1). The late blight "severity value" threshold of 18 predictinglate blight was reached on June 21 at Nampa, Idaho, near the Oregon border. Lateblight was confirmed in tomatoes and potatoes in a home garden in the outskirts ofBoise, Idaho, on June 25 and in a commercial potato field in NuAcres, Idaho, on July17. Late blight was controlled by fungicide spray programs, and the disease did notspread.

Late blight risk accumulated rapidly in mid-July at Woodburn, Oregon, in the WillametteValley (Figure 2). Late blight was not predicted by Blitecast at Woodburn, but late blightdeveloped in other fields. The field monitored and the site within this field were notrepresentative of the locations at greatest risk. Fields with vigorously growing varietiesshould be selected so that the potato canopy envelops the humidity sensor.

Severity values only reached 2 at Madras, Oregon, and late blight did not occur (Figure2). Late blight severity values reached 17 in early August at Klamath Falls, and lateblight was found about a week later. In Klamath Falls, the monitored field turned out tonot be representative of the locations at greatest risk because the field was exposed tomore air movement and was planted to the Norkotah variety that did not grow to theextent that the canopy closed over the rows. It should be noted that there had been norecord of late blight at Klamath Falls prior to 1997.

Blitecast forecasts of late blight occurrence using AgriMet weather station data and the80 percent relative humidity criteria failed to forecast late blight east of the Cascades(Figure 3). The AgriMet station at Corvallis forecast late blight on May 30, in contrast tothe weather station in the potato field at Woodburn (Figure 4).

94

Acknowledgments

We acknowledge the indispensable support of CAAR and the Oregon PotatoCommission. This work would not have been possible without the cooperation of DanChin, Ken Rykbost, Al Mosley, Steve Iverson, Steve James, Tom Kirsh, Dave Mizuta,Bob Peterson, Krishna Mohan and Mike Larkin. Constructive suggestions to thismanuscript by Mary Powelson, Ken Rykbost, and Al Mosley are greatly appreciated.

95

July 1 August 1

80

70

60

50

40

30

20

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0145 155

June 1165 175 185 195 205 215

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Figure 1. Accumulation of "Blitecast" severity values to predict potato late blight basedon 90 percent relative humidity and temperature in the potato canopies ingrowers' fields at Ontario, Owyhee Junction, Homedale, and Nampa in 1997,Malheur Experiment Station, Oregon State University, Ontario, Oregon.

Figure 2. Accumulation of "Blitecast" severity values to predict potato late blight basedon 90 percent relative humidity and temperature in the potato canopies ingrowers' fields at Madras, Klamath Falls, and Woodburn in 1997, MalheurExperiment Station, Oregon State University, Ontario, Oregon.

Madras

K.Falls - • Woodburn Threshold

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June 1 July 1 August 1

96

Figure 3. Accumulation of "Blitecast" severity values to predict potato late blight basedon 90 percent relative humidity and temperature in the potato canopy at DryLake, Nampa ID compared to the prediction based on 80 percent relativehumidity and temperature at the nearby Dry Lake AgriMet station near by,1997, Malheur Experiment Station, Oregon State University, Ontario,Oregon.

Nap 97 — — NMPI

Threshold

130 140 150 160 170 180 190 200 210 220

June 1 July 1 August 1

Figure 4. Accumulation of "Blitecast" severity values to predict potato late blight basedon 90 percent relative humidity and temperature in the potato canopy atWoodburn, Oregon, compared to the prediction based on 80 percent relativehumidity and temperature at the Corvallis AgriMet station, 1997, MalheurExperiment Station, Oregon State University, Ontario, Oregon.

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130 140 150 160 170 180 190 200 210 220June 1 July1 August 1

97

UMATILLA RUSSET POTATOES COMPARED WITHRUSSET BURBANK AND SHEPODY, 1997

Eric P. Eldredge, Clinton C. Shock, and Joey IshidaMalheur Experiment Station


Summary

Potato varieties Russet Burbank, Umatilla, and Shepody were grown in two side by sidefield trials at the Malheur Experiment Station in 1997 under sprinkler irrigation. Tuberswere dug September 18 and 19, graded, and a twenty tuber sample of each variety wasplaced in refrigerated storage. The stored samples were removed October 7 andspecific gravity, sugar percentages, and fry color were measured. The varieties RussetBurbank, Umatilla, and Shepody differed significantly for most measured parameters.Umatilla had good yield, high percent number one tubers, low production of under fourounce tubers compared to Russet Burbank, less dark stem-end fry color, and highertuber solids than Russet Burbank or Shepody.

Introduction

Russet Burbank is the old industry standard variety for processing, is late maturing andkeeps well in storage. Russet Burbank has many defects such as a tendency toproduce sugar ends (tubers with excess levels of reducing sugar that fry too dark),excessive small tubers, too many misshapen tubers, and inconsistent performance.Consequently, newer varieties are being developed for the processing industry.Shepody, a recently adopted variety for processing, has good internal qualities of lowreducing sugar and high specific gravity; it bulks the tubers faster and can be harvestedsooner than Russet Burbank; and produces more large tubers. Shepody has hadproblems with low specific gravity when grown in the Treasure Valley of eastern Oregonand southwestern Idaho. Umatilla is a new variety (A082611-7) selected by the varietydevelopment program led by Al Mosley at Corvallis, with Ken Rykbost at Klamath Falls,Steve James at Powell Butte, Oscar Gutbrod at Corvallis, Dan Hane at Hermiston, andJoey Ishida, Eric Eldredge, and Clint Shock at Ontario. Consistently across locationsand years, Umatilla has yielded as well as Shepody and Russet Burbank and hasprocessing quality better than Shepody. The trials reported here were conducted tocompare Umatilla to Russet Burbank and Shepody for tuber yield, grade, andprocessing quality.

98


Potato varieties Russet Burbank, Umatilla, and Shepody were planted May 2, 1997, inalternating three row strips, separated by border rows of Russet Burbank. The order ofthe three rows of varieties in each plot was random. The Statewide Variety Trial in thesame field also included four replicates of each of these three varieties, and receivedthe same management. Treated 2 oz seed pieces were planted 9 inches apart in therow with rows spaced 36 inches apart. Admire at 19 oz/acre was applied in the seedfurrow at planting. Standard cultural practices of weed control and fertilizer werefollowed. Urea was sidedressed after planting at 114 lb N/ac. Both trials were irrigatedwith solid set sprinklers. Solution 32 fertilizer was applied through the sprinkler systemJune 25 to supply 85 lb N/acre. Matrix herbicide was applied at 0.25 oz ai/acre on June10. The crop was protected from insects, diseases, and mites by aerial applications: onJune 24, June 30, and July 7, Bravo at 0.19 gal/acre plus Thiodan at 0.25 gal/acre,Dithane at 0.4 gal/acre on July 21, August 13 Dithane at 0.5 gal/acre, plus Kocide at0.25 gal/acre, plus sulfur at 5 lb/acre, and August 22, sulfur at 3.4 lb/acre plus Comiteat 0.29 gal/acre.The potato vines were destroyed with a flail mower September 8, and tubers were liftedwith a mechanical potato digger and picked by hand into burlap sacks September17-19. The sacks of potatoes were stored under tarps on pallets in a barn until theywere graded on September 26 and 29. Twenty tuber samples were taken of eachvariety in each plot from the Comparison Trial, and placed in refrigerated storage. OnOctober 7 the samples were taken to the J.R. Simplot fresh laboratory in Caldwell,Idaho, to measure specific gravity, fry color, and percentages of sucrose and reducingsugars. Yield, grade, and processing quality data were evaluated using ANOVA. Wheresignificant differences were present, the LSD was calculated.


On June 19, Russet Burbank plants were 20 inches tall, 30 inches wide, dark greencolor, in bud stage with 12 fully expanded leaves, and a good set of tubers averaging 1inch long. Umatilla plants were 18 inches tall, 23 inches wide, medium green color, inbud stage with 13 fully expanded leaves and tubers 1/4 inch diameter. Shepody plantswere 19 inches tall, 26 inches wide, lighter green color than the other two varieties, withfirst flowers blooming, 14 fully expanded leaves per stem, and tubers 1/2 inch long. Thepotato plants all developed uniformly, and no nutritional imbalance, insect, disease,mite, or weed problems were present to limit crop growth and development.Umatilla and Shepody produced significantly more US Number One tubers over 12 ozthan did Russet Burbank (Table 1). Umatilla and Shepody produced significantly fewer4-6 oz, and more 6-12 oz US Number One tubers than Russet Burbank. RussetBurbank produced significantly less marketable yield, more tubers less than 4 oz, andlower total yield than Umatilla or Shepody. No significant differences between varietieswere measured for US Number Two size categories, rot, and percentage of US NumberOne tubers.

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Percentage of Number One tubers over 12 oz was significantly less with RussetBurbank than Umatilla or Shepody. A significant difference was detected between eachvariety in specific gravity, with Russet Burbank the lowest in total solids, followed byShepody, and Umatilla with the highest tuber total solids. A significantly greaterpercentage of Russet Burbank tubers darkened excessively when fried, than didUmatilla or Shepody.

Table 1. Two comparisons of Russet Burbank, Shepody, and Umatilla potato yield andprocessing quality, Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

Tuber gradeUS Number One Percent US US

TotalTo4-12 oz > 12 Total No. Total Small Number Tuber Dark fryoz Two marketable < 4 oz yield One solids colors

Variety cwt/acre c/oComparison TrialRusset 234.5 30.1 264.6 38.4 318.1 110.2 414.9 63.7 20.54 23.8BurbankShepody 253.2 94.3 346.6 62.5 429.4 62.2 474.8 72.8 21.31 10.3

Umatilla 249.8 100.9 350.8 54.4 425.3 57.2 467.7 75.3 22.93 2.3LSD (0.05) NS 25.7 34.3 19.3 31.3 10.7 26 5 0.91 7.4

Statewide Variety TrialRusset 288.3 52.5 340.8 142.5 483 101.6 592 57.5 1.0747 12.5BurbankShepody 140.7 150.7 291.3 159.1 450 29.1 503.1 60 1.0788 0

Umatilla 254.4 128.9 383.3 113.6 497 54.6 561.2 68.4 1.0876 0

LSD (0.05) 56.7 47.9 69.8 NS NS 11.8 87.4 5.9 0.0046 NA

Average of trialsRusset 261.4 41.3 302.7 90.5 400.6 105.9 503.5 60.6BurbankShepody 196.5 122.5 319 110.8 439.7 45.7 518 66.4

Umatilla 252.1 114.9 367.1 84 461.2 55.9 485.4 71.9

NA: not availableNS: not significant

100

PREEMERGENCE HERBICIDES FOR WEED CONTROL IN POTATOES

Corey V. Ransom and Joey IshidaMalheur Experiment Station


Introduction

Effective weed control and crop tolerance are important herbicide traits for maximizingtuber yield and quality in potatoes. Trials were conducted to evaluate new herbicidesfor weed control efficacy and crop tolerance in Russet Burbank, Shepody, and Umatillapotatoes.

Methods

Three potato varieties (Russet Burbank, Shepody, Umatilla) were planted in a silt loamsoil with pH 7.9 and 1.6 percent organic matter. Seed pieces were planted every 9inches in 36-inch beds. Plots were 12 feet wide by 30 feet long and consisted of onerow of each variety with border rows of Russet Burbank on each side. Potatoes wereplanted May 1 and 2, 1997. At planting, Admire insecticide at 19 oz/acre was applied inthe planter furrow. Potatoes were sidedressed with 114 lbs N/acre, May 15 as urea.Also 85 lbs N/acre as solution 32 was applied through the sprinklers on June 25.

Preemergence herbicides were applied May 23 and postemergence applications ofMatrix were made June 10. Treatments were applied with a CO 2 -pressurizedbackpack sprayer delivering 20 gpa at 30 psi. The experiment was a split-plot designwith herbicide treatment as the main plot and varieties as the split-plots. Treatmentswere replicated four times. Plots were irrigated with sprinklers according to croprequirements throughout the season. Crop injury was evaluated visually June 2, 17,and 24. Weed counts were taken June 17 and 24, and weed control was visuallyevaluated on June 17, June 24, and September 5. Potatoes were harvestedSeptember 17 to 19. Potatoes were graded October 9 to 16.

Results

Weed Control. Eptam applied alone provided the least redroot pigweed control of alltreatments, but still controlled 83 percent (Table 1). Sonalan applied alone had thelowest control of common lambsquarters (91 percent) and barnyardgrass (76 percent).Sonalan and Sencor applied alone and tank mixed together provided less than 30percent hairy nightshade control. Isoxaflutole alone at 0.05 lb ai/acre was a little weakon redroot pigweed and barnyardgrass. However, isoxaflutole at rates from 0.07 to

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0.12 lb ai/acre provided excellent control of all weed species present. Unfortunately,the higher rates of isoxaflutole injured all three potato varieties, with the 0.12 lb ai/acrerate resulting in the greatest injury. The other treatments, including Sonalan alone andin tank mixtures, did not injure potatoes. Weed control was similar later in the season(Table 2).

Potato Yields. Undersize and US Number One 6 to 12 oz tuber yields were differentdepending on the herbicide treatment and the potato variety (Table 3). Russet Burbankproduced more undersize tubers than Shepody or Umatilla. Herbicide treatmentsreduced the amount of undersize tubers in Russet Burbank but had no effect onundersize tuber production in the other two varieties. Number one tubers in the 6 to 12oz range were also affected by herbicide treatment and potato variety. Some herbicidetreatments increased 6 to 12 oz sized tubers in Russet Burbank and Umatilla whencompared to the control. In Shepody, only isoxaflutole (0.12 !b ai/acre) increased 6 to12 oz tubers compared to the control. In Russet Burbank and Umatilla, the sametreatment, isoxaflutole (0.12 lb ai/acre), reduced the amount of 6 to 12 oz tubers,presumably in response to the observed injury.

For all other yield parameters, potato varieties responded similarly in response to theherbicide treatments. Both treatment means averaged over potato variety, and varietymeans averaged over herbicide treatment will be discussed. Total yield, total numberones, and total marketable yield were increased by all treatments compared to theuntreated control (Table 4). The high rate of isoxaflutole (0.12 lb ai/acre) resulted inone of the lowest total and lowest marketable yield of the herbicide treatments. Thetank mixture of Sonalan plus Eptam was among the highest yielding of any herbicidetreatment.

Averaged over herbicide treatments, Shepody produced the highest total andmarketable yield and the highest yield of US Number One tubers (Table 5). Umatillayielded lower than Shepody. Russet Burbank had the lowest yields in this trial. BothShepody and Umatilla produced a higher percentage of number one potatoes thanRusset Burbank. The Umatilla plants grew slowest early in the season in this trial,which may have been due to relatively more dormant potato seed. The Umatilla plantswere at a competitive disadvantage to the Shepody and Russet Burbank plants due totheir small size, which may not represent their real comparative yield potential.

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Table 1. Weed control and injury in potatoes treated with preemergence herbicides,Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1997.

Weed control /Potato

Treatment Rate Timing Pigweed Lambsquarters Barnyardgrass H. nightshade injury'

lb ai/acre cyo

Sonalan HFP 0.94 PRE 95 91 76 29 0Eptam 3 PRE 83 100 100 74 3Matrix 0.02 PRE 100 98 98 75 0Sencor 0.25 PRE 100 100 96 21 0Isoxaflutole 0.05 PRE 91 100 88 78 5Isoxaflutole 0.07 PRE 96 100 100 98 18Isoxaflutole 0.09 PRE 100 100 100 93 23Isoxaflutole 0.12 PRE 100 100 100 99 41Isoxaflutole + Sencor 0.071 + 0.25 PRE 100 100 100 99 26Isoxaflutole + Eptam 0.071 + 3.0 PRE 100 100 100 100 24Sonalan HFP + Eptam 0.94 + 3.0 PRE 100 100 98 84 2Sonalan HFP + Sencor 0.94 + 0.25 PRE 100 100 100 16 0Sonalan HFP + Matrix 0.94 + 0.016 PRE 100 100 100 77 0Isoxaflutole + Matrix 0.071 + 0.016 PRE 100 100 100 93 3Eptam + Sencor 3.0 + 0.25 PRE 100 100 100 78 0Eptam + Matrix 3.0 + 0.016 PRE 100 100 100 90 0Sencor + Matrix 0.25 + 0.016 PRE 100 100 95 55 0Sonalan HFP + Eptam + 0.94 + 3.0 + PRE 100 100 100 83 1Sencor 0.25Sonalan HFP + Matrix 0.94 + PRE + 100 100 98 88 5

0.016 POSTIsoxaflutole + Matrix 0.071 + PRE + 100 100 100 99 12

0.016 POSTEptam + Sencor + Matrix 3.0 + 0.25 + PRE + 100 100 100 100 4

0.016 POSTUntreated 0 0 0 0 0LSD (0.05) 7.7 5.5 10 22 14

'Weed control and potato injury were evaluated June 24, 1997. Injury ratings: 0 = no visible injury, 100= death of the plant.

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Table 2. Weed control evaluations in potatoes, September 5, 1997, MalheurExperiment Station, Oregon State University, Ontario, Oregon.

Weed controlTreatment Rate Timing Pigweed Lambsquarters Barnyardgrass H. nightshade

lb ai/acre %Sonalan HFP 0.94 PRE 65 85 64 36Eptam 3 PRE 70 90 96 82Matrix 0.02 PRE 91 85 96 70Sencor 0.25 PRE 98 99 90 13Isoxaflutole 0.05 PRE 73 98 78 78Isoxaflutole 0.07 PRE 93 96 96 92Isoxaflutole 0.09 PRE 91 100 98 90Isoxaflutole 0.12 PRE 100 100 100 98Isoxaflutole + Sencor 0.071 + 0.25 PRE 99 100 100 95Isoxaflutole + Eptam 0.071 + 3.0 PRE 99 100 99 99Sonalan HFP + Eptam 0.94 + 3.0 PRE 95 98 100 92Sonalan HFP + Sencor 0.94 + 0.25 PRE 100 100 99 29Sonalan HFP + Matrix 0.94 + 0.016 PRE 100 98 100 68Isoxaflutole + Matrix 0.071 + 0.016 PRE 100 100 99 88Eptam + Sencor 3.0 + 0.25 PRE 98 100 100 85Eptam + Matrix 3.0 + 0.016 PRE 100 100 100 88Sencor + Matrix 0.25 + 0.016 PRE 100 100 100 53Sonalan HFP + Eptam + 0.94 + 3.0 + PRE 100 100 100 88Sencor 0.25Sonalan HFP + Matrix 0.94 + PRE + POST 98 100 100 74

0.016

Isoxaflutole + Matrix 0.071 + PRE + POST 100 100 100 990.016

Eptam + Sencor + Matrix 3.0 + 0.25 + PRE + POST 100 100 100 960.016

Untreated 0 0 0 0LSD (0.05) 6 8 10 14

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Table 3. Yield of undersize and US Number One 6 to 12 oz tubers as influenced bypotato variety and herbicide treatment, Malheur Experiment Station, OregonState University, Ontario, Oregon, 1997.

Potato yield

Less than 4 oz 6 to 12 oz

Russet RussetTreatment

Rate Timing Burbank Shepody Umatilla Burbank Shepody Umatilla

lb ai/acre cwt/acre

Sonalan HFP 0.94 PRE 116 53 55 148 192 222

Eptam 3 PRE 121 58 63 124 182 183Matrix 0.02 PRE 105 55 52 174 169 187

Sencor 0.25 PRE 124 53 68 136 198 175

Isoxaflutole 0.05 PRE 103 56 57 170 174 173

Isoxaflutole 0.07 PRE 86 56 50 136 200 162Isoxaflutole 0.09 PRE 96 53 58 116 187 134Isoxaflutole 0.12 PRE 86 59 53 92 208 123Isoxaflutole + Sencor 0.071 + 0.25 PRE 90 54 46 111 176 192Isoxaflutole + Eptam 0.071 + 3.0 PRE 81 48 47 133 173 142Sonalan HFP + Eptam 0.94 + 3.0 PRE 118 53 55 154 178 225Sonalan HFP + Sencor 0.94 + 0.25 PRE 137 62 55 131 184 202Sonalan HFP + Matrix 0.94 + 0.016 PRE 110 66 50 151 163 177Isoxaflutole + Matrix 0.071 + 0.016 PRE 110 68 57 120 173 178Eptam + Sencor 3.0 + 0.25 PRE 114 63 61 152 192 171Eptam + Matrix 3.0 + 0.016 PRE 107 62 66 160 169 197Sencor + Matrix 0.25 + 0.016 PRE 118 59 56 173 173 205Sonalan HFP + Eptam 0.94 +3:0 + PRE 124 58 62 159 182 190+ Sencor 0.25Sonalan HFP + Matrix 0.94 + PRE + 112 69 55 160 198 198

0.016 POSTIsoxaflutole + Matrix 0.071 + PRE + 98 62 52 109 173 157

0.016 POSTEptam + Sencor + 3.0 + 0.25 + PRE + 115 56 53 141 183 196Matrix 0.016 POSTUntreated 146 68 61 82 155 122LSD (0.05) Herbicide x Variety 20 45

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Table 4. Potato yields in response to herbicide treatments averaged across varieties, Malheur Experiment Station,Oregon State University, Ontario, Oregon, 1997.

Potato yield and grade

Unmarketable US number one Total Total Total

Treatment

Rate Timing Rat Culls Undersize 4-6 oz 6-12 oz > 12 oz Total % No. 2 marketable yield

lb ai/acre cwt/acre ----------cwt/acre

Sonalan HFP 0.94 PRE 5 18 74 74 187 61 322 71 30 352 450

Eptam 3 PRE 6 26 81 74 163 66 303 65 47 350 461

Matrix 0.02 PRE 8 28 70 69 177 56 301 66 46 347 453

Sencor 0.25 PRE 5 19 82 77 170 56 303 68 34 338 443

Isoxaflutole 0.05 PRE 10 21 72 69 172 68 309 68 42 351 453




Isoxaflutole + Sencor 0.071 + 0.25 PRE 7 27 64 64 160 62 286 65 50 336 433

Isoxaflutole + Eptam 0.071 + 3.0 PRE 7 37 59 57 149 72 279 64 55 334 437

Sonalan HFP + Eptam 0.94 + 3.0 PRE 7 23 76 73 186 77 336 68 45 381 486

Sonalan HFP + Sencor 0.94 + 0.25 PRE 8 19 84 73 172 53 298 67 32 330 443

Sonalan HFP + Matrix 0.94 + 0.016 PRE 12 29 75 74 164 71 308 66 44 353 469

Isoxaflutole + Matrix 0.071 + 0.016 PRE 6 25 78 70 157 65 291 63 60 352 462

Eptam + Sencor 3.0 + 0.25 PRE 12 17 79 76 172 62 309 66 46 355 463

Eptam + Matrix 3.0 + 0.016 PRE 11 29 79 69 175 67 311 65 46 357 476

Sencor + Matrix 0.25 + 0.016 PRE 9 29 78 74 184 56 314 65 50 364 479

Sonalan HFP + Eptam 0.94 + 3.0 + PRE 9 25 81 71 177 76 325 67 43 368 482+ Sencor 0.25Sonalan HFP + Matrix 0.94 + PRE + 8 28 79 69 186 64 318 66 45 363 477

0.016 POSTIsoxaflutole + Matrix 0.071 + PRE + 8 31 71 62 146 72 280 63 53 334 443

0.016 POSTEptam + Sencor + 3.0 + 0.25 + PRE + 11 20 74 81 173 74 329 68 46 374 480Matrix 0.016 POST

Untreated

5 12 92 75 119 26 221 63 18 239 348

LSD (0.05)

NS 12 NS 12 NS 21 27 4 13 28 25

Table 5. Potato variety yields averaged over herbicide treatments, Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

Potato yield and grade

Unmarketable US number one Total Total Total

Variety Rot Culls Undersize 4-6 oz 6-12 oz > 12 oz Total % No.2 marketable yield

cwt/acre-- % cwt/acre---

Russet Burbank 5 16 110 88 138 20 245 58 41 286 418

Shepody 6 34 59 62 181 95 338 69 53 390 489

Umatilla 13 25 56 60 178 73 310 70 40 351 445

LSD (0.05) 3 5 NS 4 NS 7 14 2 5 14 12

POTATO VARIETY TRIALS AT ONTARIO, 1997

Clinton C. Shock, Ken A. Rykbost, Eric P. Eldredge, and Joey IshidaMalheur Experiment Station


Introduction

The Oregon potato variety development program evaluates approximately 80,000single-hill selections annually from breeding programs in Idaho, Colorado, and NorthDakota. These potato lines progress through the selection process until they arediscarded or, as occurs more rarely, are named and released as a variety. TheMalheur Experiment Station (MES) participates in the overall effort by conductingreplicated yield trials at the Preliminary, Statewide, and Western Regional levels. Over100 selections were included in these trials at MES in 1997. In 1997, additional trialswere conducted to evaluate Umatilla Russet compared to Russet Burbank andShepody.

The normal progression of a new line through the potato development program startswith the plant breeder who crosses two prospective parents. The resulting true seed(like a tiny tomato seed) is planted in an Oregon State University greenhouse inCorvallis. These small plants form tubers that are planted in single-hill trials. The bestof the single-hills go to 4 hill trials, then to seed increase. From seed increase,successful lines are entered successively in the Preliminary Yield Trial, StatewideVariety Trial, Tri-state Trials and finally the Western Regional Trials. The remainingsuccessful varieties are increased in commercial seed production and released aswarranted.

Two Oregon selections will be released in early 1998. Umatilla Russet (A082611-7) is aprocessing variety for French fry production that has performed very well in theTreasure Valley and in the Columbia Basin. Over 400 acres of A082611-7 seed werecertified in 1997. Legend Russet (COO83008-1) has performed well for French fryproduction in the Treasure Valley of Eastern Malheur County, Oregon, andSouthwestern Idaho, and for fresh market in Eastern Idaho. Over 160 acres ofC0083008-1 seed passed certification in 1997. Several other Oregon selections are inadvanced stages of evaluation and appear to be candidates for release. Three russetskinned selections and two round white selections from the Statewide Variety Trial willbe advanced to regional trials in 1998. Most of the entries in the 1997 StatewideVariety Trial exceeded the standard varieties in yield, quality, or both.

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Oregon has made considerable progress in the past 10 years in potato varietyimprovement. Russet Burbank, the long-time industry standard for fresh market andFrench fry production, requires high inputs and is vulnerable to several physiologicaldisorders. It is no longer the dominant potato variety in the Treasure Valley or theKlamath Basin. New varieties have also captured significant acreage in southeasternIdaho and the Columbia Basin. However, the newer varieties that are replacing RussetBurbank also have weaknesses. Traditional breeding programs continue to produceselections with superior quality for specific markets. Recently, through geneticengineering techniques, standard varieties are being altered to incorporate disease orpest resistance, or to improve other characteristics. A third area being pursued is lineselections within a variety. Potato selections from all of these methods were included inmaterial evaluated in the Oregon potato variety development program in 1997. Thisreport summarizes the performance of selections in Oregon and the region with specialemphasis on variety performance at Ontario in 1997. Similar trials are conducted eachyear at Klamath Falls, Hermiston, and Powell Butte.

Materials And Methods

The Western Regional Trial, the Statewide Variety trial, and the Preliminary YieldVariety Trial were all planted on May 2 in the same field of Owyhee silt loam andreceived the same management. The Preliminary Yield Trial included 5 standardvarieties and 67 numbered selections in 35-hill plots with 2 replications. Five standardvarieties and 19 numbered selections were included in the Statewide Variety Trial. TheWestern Regional Trial included 3 standard varieties, 10 numbered selections, and 5line selections of Russet Norkotah in 30-hill plots and 4 replications. All trials werearranged in a randomized complete block designs.

Treated 2 oz seed pieces were planted 9 inches apart in the row with rows spaced 36inches apart. Admire at 19 oz/acre was applied in the seed furrow at planting. Standardcultural practices of weed control and fertilizer were followed. Urea was sidedressedafter planting at 114 lb N/acre. The potato crop was grown to harvest with solid setsprinkler irrigation. Solution 32 fertilizer was applied through the sprinkler system June25 to supply 85 lb N/acre. Matrix herbicide was applied at 0.25 oz ai/acre on June 10.The crop was protected from insects, diseases, and mites by aerial applications: Bravoat 0.19 gal/acre plus Thiodan at 0.25 gal/ac on June 24, June 30, and July 7, Dithane at0.4 gal/acre on July 21, Dithane at 0.5 gal/acre, plus Kocide at 0.25 gal/acre, plus sulfurat 5 lb/acre on August 13, and sulfur at 3.4 lb/acre plus Comite at 0.29 gal/acre onAugust 22.

The potato vines were shredded with a flail mower September 8, and tubers were liftedwith a mechanical potato digger and picked by hand into burlap sacks in lateSeptember. External tuber characteristics were noted for each replication duringharvest. The sacks of potatoes were stored under tarps on pallets in a barn until theywere graded. USDA grade standards were followed to separate B size (under 4 oz),U.S. Number One tubers (4 to 12 oz and over 12 oz), U.S. Number Two tubers over 4

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ounces, and culls. Yields of Number One tubers were not adjusted for externalblemishes such as rhizoctonia or scab, or internal defects such as hollow heart orbrown center. Ten large (usually over 10 ounces) tubers from each plot were cutlongitudinally and inspected for internal defects. The data on external and internaldefects is not presented in this report.

Twenty tuber samples were taken of each variety in each plot from all trials and placedin refrigerated storage. In November the tubers were evaluated for specific gravity andfry color. Specific gravity was measured by the weight-in-air, weight-in-water method.Data on yield, grade, and processing quality were evaluated using ANOVA and NCSSsoftware. Where significant differences were present, the LSD (0.05) was calculated.

Decisions on the disposition of selections at all levels of evaluation are based on dataaccumulated at all trial locations. The Preliminary Yield Trial and Statewide VarietyTrial data from four Oregon sites (Hermiston, Ontario, Powell Butte, and Klamath Falls)are compiled and reviewed by Oregon potato variety development committee members.Cooperators at Aberdeen, Idaho, compile Tri-state and western regional trial data,which is reviewed at annual committee meetings attended by up to 30 cooperators andindustry representatives.

Results And Discussion

The 1997 growing season was favorable for the potato production at Ontario. No hail,frost, or late blight occurred in 1997.

Western Regional Trial. Russet Burbank had among the lowest yield of U.S. NumberOne tubers and among the highest yield of U.S. Number Two tubers and culls of allentries (Table 1). The selections A82360-7 and TX1385-12RU were among the mostproductive of total yield and marketable yield. The line A82360-7 was the highestyielding variety over the nine Pacific Northwest sites in 1997 and was also highlyproductive at Ontario.

Three Texas and two Colorado line selections of Russet Norkotah were included in thistrial. All had later vine maturity than the standard Norkotah entry (data not shown). TheColorado selections (CORN-3 and CORN-8) and the Texas selection (TXNS 223) wereentered in the regional trial for the first time in 1997. In 1996 trials, TXNS 112 andTXNS 278 were only slightly later in vine maturity than the standard Norkotah acrossseven locations. All Norkotah line selections were similar to or higher than the standardNorkotah in specific gravity. CORN-3 had a higher incidence of hollow heart at KlamathFalls, Ontario, and Aberdeen than Russet Norkotah. This selection produced a higheryield of large tubers compared to the other Russet Norkotah selections. CORN-3achieved the highest Number One yield, but tuber size was excessive. CORN-3, andCORN-8 produced significantly higher Number One yields than the standard Norkotah.TXNS 278 was the lowest yielding Norkotah line selection.

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Three entries: A82360-7; C085026-4; and TXAV657-27Ru, have completed threeyears in regional trials. Two selections, A8792-1 and C087009-4, were discarded. Allother selections in the 1997 trial will be continued in the program. The Colorado andTexas selections of Russet Norkotah have undergone extensive seed increase and willconstitute a significant portion of 1998 acreage in these states. Averaged over nineregional trial sites in 1997, all of these strains produced higher Number One yields thanthe standard Norkotah by 20 to 80 cwt/acre.

Statewide Variety Trial. Russet Burbank produced a high total yield, but manyNumber Two tubers and culls (Table 2). Across all locations, Russet Burbank rankedlow in yield of Number One tubers, but the U.S. Number One yield of Russet Burbankwas reasonable at Ontario in 1997. The overall quality and performance of entries inthis trial was very good. Most of the Russet-skinned selections were attractive inappearance, had relatively good tuber type, produced high yields, and had fewerexternal and internal defects than Russet Burbank. Russet Norkotah had 182 cwt/acreless total yield than Russet Burbank.

The two round, white, chipping selections, A091812-1 and A091812-2, ranked 1st and2nd, respectively, in Number One yields across all locations and will advance to theregional chipping trial in 1998. Both lines produced very high yields. Late vine maturityand attached stolons were noted in both selections. Six additional selections will beretained in the statewide trial in 1998. Only three selections from this trial werediscarded from the program.

The official release of A082611-7 as Umatilla Russet and C0083008-1 as RussetLegend is planned for early 1998. Both selections have good processing quality. RussetLegend is considered acceptable for fresh market by growers in Eastern Idaho.

A085165-1, an attractive fresh market russet variety, completed three years ofevaluation in the regional trial in 1996, has been increased in greenhouse culture in1997, and will be supplied to seed growers for rapid increase and commercialevaluation. It resembles Russet Norkotah, which was the male parent, in appearance,and typically exceeds Norkotah in Number One yield by 100 cwt/acre or more.

The lines A092173-2 and A087277-6 were among those with the highest marketableyield at Ontario in 1997. The russeted selection A087277-6 was included in theWestern Regional Trial for the first time in 1997. It will remain in the 1998 regional trialas a dual purpose line. Another dual purpose russeted line, A089128-4, was includedin the 1997 Tri-state trial and will advance to the regional trial in 1998. The linesA090014-1 and A088103-3 are being advanced to the Tri-state trial and areconsidered dual purpose, attractive russets. The line A090319-1 was probably themost attractive russet-skinned selection in this trial. It has very nice yellow flesh color.This selection will be entered in the regional specialty variety trial in 1998. It producedlower yields than most other clones in both 1996 and 1997.

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Preliminary Yield Trial. Most of the entries in this trial were selections from crossesmade at Aberdeen, Idaho, in 1992 and 1993. Several entries had excessive vinegrowth and immature skins at harvest which resulted in serious skinning damage.Yields were acceptable, but several of the selections, including Russet Burbank andShepody, had many off-type, rough, or growth cracked tubers. Russet Burbank rankedlow in Number One yield (Table 3).

After reviewing data from all locations, only 11 lines of the 67 tested were selected forfurther evaluation (Table 3). All of these are russeted lines. Several selections hadadequate dry matter content and fry color for processing as French fries. Ranking inNumber One yields across four locations ranged from 1st for A093317-5, whichproduced the highest Number One yield at three locations, to 32nd for A092281-3.None of the clones saved in 1997 were equal to Russet Norkotah in tuber type andappearance. Entries selected from this trial were advanced to the Statewide VarietyTrial.

Summary

The quality of advanced selections in the Oregon and regional potato varietydevelopment programs was excellent. Oregon will formalize releases for RussetLegend and Umatilla Russet in 1998. Idaho plans to release a round white chippingselection, ND01496-1, which was selected from the Oregon program; a red-skinnedselection, A82705-1R as Idarose; and two russeted selections, A81473-2 and A8495-1,in 1998. Colorado plans to release a russet selection, AC83064-6, and a red-skinnedselection, DT6063-1R in 1998. Releases planned for the near future in Texas include around white chipping selection, ATX85404-8, and a russet selection, TXAV657-27Ru.Texas and Colorado continue moving forward with development of Russet Norkotahselections. Based on evaluation of the russet skinned selections at MES, UmatillaRusset and Russet Legend have promise for processing based on marketable yield,high percentage of U.S. Number One tubers, high specific gravity, and light fry color.

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Table 1. Yield, grade, fry color, and specific gravity of seventeen potato varieties andselections in the Western Regional Trial, Malheur Experiment Station,Oregon State University, Ontario, Oregon, 1997.

Yield by, market grade Quality TotalToTotal U S Total U S Fry Specific4 - 6 oz 6 - 12 > 12 oz No. 1s No. 2s Marketable yield color gravity

oz cwt/acre

R. Burbank 69.1 190.9 61.1 321.1 146.1 467.2 580.0 37.7 1.075

Ranger R. 32.5 180.5 140.1 353.1 97.1 450.3 529.5 46.6 1.093

R. Norkotah 70.4 206.4 58.1 334.9 19.4 354.3 409.0 37.2 1.071

A82360-7 94.4 332.0 91.5 517.9 79.6 597.5 714.1 52.5 1.086A8792-1 26.8 130.3 208.6 365.6 119.1 484.7 575.4 48.0 1.094AC87804-3 38.4 167.6 142.7 348.7 80.9 429.6 491.3 46.2 1.097A087277-6 52.5 231.5 117.3 401.3 64.3 465.5 532.0 48.3 1.091C085026-4 44.8 149.9 105.6 300.3 46.7 347.0 405.2 48.3 1.086C087009-4 74.7 225.7 76.8 377.2 87.1 464.3 534.5 56.2 1.095CORN-3 36.1 156.4 180.1 372.6 118.4 491.0 569.0 40.7 1.076CORN-8 50.4 189.3 148.1 387.8 70.0 457.7 513.6 40.9 1.07ND840-1 85.2 251.0 112.4 448.6 72.6 521.1 630.7 43.4 1.082TX1385-12RU 44.4 147.0 210.0 401.4 149.4 550.8 647.8 54.0 1.081TXAV657-27RU 51.4 183.5 174.1 408.9 55.8 464.7 536.2 47.2 1.08TXNS112 55.0 215.4 117.8 388.3 61.8 450.1 511.4 38.2 1.071TXNS223 78.6 224.4 71.0 374.0 77.4 451.3 535.0 37.9 1.071TXNS278 54.3 211.0 134.2 399.5 67.3 466.8 537.6 38.7 1.072Mean 56.4 199.6 126.4 382.4 83.1 465.5 544.3 44.8 1.082LSD(0.05) 17.5 40.4 63.1 78.8 33.2 79.9 77.1 4.4 0.004

Varieties

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SUGAR BEET VARIETY TRIAL RESULTS FOR 1997

Clinton C. Shock and Joey IshidaMalheur Experiment Station


Introduction

Sugar beet seed companies and the beet growers associations have cooperated formany years to test sugar beets at the Malheur Experiment Station. Commercial cultivarsand experimental lines of sugar beets were evaluated to identify lines with high sugaryields and root quality. A joint seed advisory committee evaluates the accumulatedperformance data for the varieties over several years and locations, then it restrictsgrowers in Idaho and Malheur County of Oregon to planting only those varieties rankingabove minimum industry requirements.

Procedures

Twenty-three commercial cultivars and 32 experimental lines (including check cultivars)of sugar beets were evaluated in separate trials conducted at the Malheur ExperimentStation, Ontario, Oregon. Sugar beets were planted in Owyhee silt loam and Greenleafsilt loam where winter wheat had been grown the previous year. Fields were plowed inthe fall of 1996. For the commercial cultivars, the March 13 test results in the first foot ofsoil were NO 3-N 6 lb/acre, NH 4-N 9 lb/acre, and in the second foot were NO 3-N 9 lb/acre,NH4-N 9 lb/acre. Extractable phosphorus was 23 ppm, and zinc was 1.5 ppm. Soil pHwas 7.7, and soil organic matter was 1.7 percent. For the experimental lines, the March13 test results in the first foot of soil were NO 3-N 6 lb/acre, NH 4-N 15 lb/acre, and in thesecond foot were NO 3-N 9 lb/acre, NH 4-N 7 lb/acre. Extractable phosphorus was 22ppm, and zinc was 1.8 ppm. Soil pH was 7.7, and soil organic matter was 1.6 percent.

Nortron was banded 11 inches wide at 1 qt/acre for weed control and was incorporatedusing a spike-tooth bed harrow before planting. Each entry was replicated eight timesusing a randomized complete block experimental design. Each plot was four rows wideand 23 feet long with 3-foot alleys separating plots. Approximately 12 viable seeds perfoot of row were planted in each plot row. The seed was planted on April 9 to 11 withcone-seeders mounted on a John Deere model 71 flexi-planter equipped with discopeners. On April 15, trials were corrugated, and Counter 15G was applied in a bandover the row at 6 oz/1000 ft of row. The sugar beet trials were furrow-irrigated to furnishmoisture for uniform seedling emergence. On April 29 herbicides Progress at 0.25 lbai/acre, Stinger at 0.05 lb ai/acre, and Poast at 0.10 lb ai/acre were applied by abroadcast spray. The sugar beets were hand-thinned May 19 to 22; spacing betweenplants was approximately 7 inches. On June 6 Poast at 1.5 pt/acre was applied. The

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crop was sidedressed with 245 lb N/acre as urea because of very low preplant soil nitrateand ammonium on May 30.

Treflan at 1 pint/acre plus Eptam at 3 pint/acre were applied for weed control June 10and incorporated with sinner weeders. Beets were mechanically cultivated for the lasttime on June 16. Powdery mildew was controlled with 60 lb/acre of sulfur dust on July27, Bayleton at 1 lb/acre on July 31 following a rain storm, then 60 lbs/acre of powderedsulfur on August 28, all applied by air.

Sugar beets from the commercial cultivars were harvested October 13 and 14, and thosefrom the experimental trial were harvested October 7 to 10. The foliage was removed bya flail beater, and the crowns were clipped with rotating scalping knives. The roots fromthe two center rows of each four-row plot were dug with a single-row, wheel-type lifterharvester, and all roots in each 23 feet of row were weighed and corrected by tare tocalculate root yields. A sample of eight beets was taken from each of the harvested rowsand analyzed by Amalgamated Sugar Company for percent sucrose, pulp nitratenitrogen, and conductivity. The percent extraction was calculated using an empiricalformula that used percent sucrose and conductivity readings as factors.

Variety differences were calculated using ANOVA and protected least significantdifferences at the 5 percent level, LSD (0.05). Performance was compared with theestablished commercial varieties HM WS PM9, HM WS91, Beta 8422, and ACH 211.

Results

Cultivar performance was analyzed statistically and ranked by recoverable sugar withineach company's entries (Tables 1 and 2). Yields of estimated recoverable sugar fromcommercial cultivars ranged from a high of 13,545 lb/acre of sugar to a low of 10,578lb/acre of sugar, with a variety mean of 12,247 lb/acre of sugar. Among the top yieldingcultivars were HM PM 21, HM Owyhee, HM Oasis, Beta 8450, and Beta 8118 (Table 1).

The experimental lines were planted in a field with generally lower productivity than thecommercial cultivars, but with no history of sugar beet production. Beet tonnage rangedup to 58.67 ton/acre. The experimental lines were harvested first, perhaps contributingto the sucrose percentage of 15.79 compared to 16.57 for the commercial cultivars.Yield of recoverable sugar from the experimental lines ranged from 14,816 lb/acre ofsugar to a low of 11,052 lb/acre of sugar, with an entry mean of 12,731 lb/acre of sugar.Among the top yielding lines were the Betaseed lines 5KG 6906, 5KG 6908, and 5KG6907 (Table 2).

117

Table 1. Root yields, sugar yields and root quality data from sugar beet lines entered ascommercial lines at the Malheur Experiment Station, Oregon State University,Ontario, 1997.

Company VarietyYield Sucrose Nitrate Conductivity Extraction Recoverable sugar

ton/acre ppm mmho OA lb/acre

Hilleshog Mono-Hy HM PM 21 45.3 17.18 97 0.6 87 13,545.

HM Owyhee 45.33 17.12 152 0.64 86.5 13,425.

HM Oasis 45.21 16.87 126 0.64 86.4 13,187.

HM Canyon 44.78 16.66 185 0.74 85.1 12,695.

HM Emblem 43 16.98 128 0.62 86.6 12,647.

HM WS62 44.13 16.44 155 0.68 85.7 12,439.

HM WSPM9 44.72 16.2 150 0.68 85.7 12,411.

HM Sierra 42.57 16.89 154 0.68 85.9 12,350.

HM 9155 44.9 16.26 172 0.78 84.5 12,341.

HM WS91 41.92 16.56 184 0.74 85 11,825.

HM RZ 72 42.75 16.26 196 0.76 84.7 11,767.

Betaseed Beta 8450 45.18 17.1 222 0.78 84.6 13,061.

Beta 8118 45.14 16.93 160 0.73 85.2 13,022.

Beta 8468 44.22 16.76 134 0.75 84.9 12,588.

Beta 8757 43.83 16.85 177 0.76 84.9 12,540.

Beta 8422 42.87 16.75 180 0.76 84.8 12,176.

Beta 4035 R 43.18 15.66 206 0.79 84.2 11,386.

American Crystal ACH 203 42.32 16.58 167 0.73 85.2 11,965.

ACH 211 40.24 17.01 134 0.61 86.8 11,883.

Holly Rival 40.51 16.13 195 0.76 84.7 11,067.

Rhizoguard CT 40.15 15.93 180 0.72 85.2 10,909.

SS-781R 40.33 15.68 167 0.83 83.7 10,578.

Seedex SX 1505 42.32 16.33 153 0.67 85.9 11,881.

Mean 43.26 16.57 164 0.72 85.4 12,248

LSD (0.05) 1.50 0.47 39 0.05 0.7 578

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Table 2. Root yields, sugar yields, and root quality data from sugar beet lines enteredas experimental lines at the Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

EstimatedRoot Sugar Root recoverable

Company Variety yield content Conductivity NO3-N Extraction sugarton/acre % mmho ppm % lb/acre

Hilleshog Mono-Hy HM 2929 51.06 15.32 0.71 211 85.1 13,318HM 2928 47.51 16.28 0.68 180 85.7 13,259HM 2979 50.08 15.6 0.84 262 83.5 13,023HM 2926 47.44 16.07 0.72 207 85.1 12,986

HM WS PM9 48.86 15.53 0.76 194 84.6 12,819HM 2977 49.5 15.09 0.76 243 84.4 12,616

HM WS91 46.37 15.97 0.82 221 83.9 12,425HM 2978 47.54 14.98 0.96 358 81.7 11,635HM Pillar 40.18 16.65 0.71 196 85.4 11,427HM RZ20 41.25 15.76 0.72 219 85 11,052

Betaseed 5KG 6906 58.67 15.1 0.82 240 83.6 14,8165KG 6908 57.04 15.03 0.86 284 83.1 14,2415KG 6907 56.49 15.01 0.83 233 83.5 14,1524KG 5996 48.55 16.59 0.78 190 84.5 13,6073BG 6111 50.39 15.91 0.83 211 83.7 13,417Beta 8348 51.55 15.37 0.83 298 83.6 13,2235CG 7347 46.03 16.48 0.74 135 85.1 12,9034KG 5983 44.65 16.75 0.77 154 84.7 12,6845CG 7292 46.52 15.88 0.8 171 84.1 12,4235CG 7382 46.98 15.55 0.79 189 84.1 12,293Beta 8422 46.09 15.84 0.86 206 83.3 12,167

American Crystal ACH 9622 52.72 15.49 0.82 185 83.7 13,669ACH 9623 50.02 15.69 0.74 183 84.8 13,288ACH 9707 45.02 16.31 0.7 183 85.6 12,550ACH 211 43.73 16.34 0.7 189 85.5 12,212ACH 9706 42.26 16.6 0.69 221 85.6 12,002

Seedex SX1511 44.62 15.91 0.77 160 84.5 11,981SX1509 46.03 15.43 0.85 233 83.3 11,823

Holly 97HX724 50.02 15.99 0.81 250 84 13,42497HX705 50.7 15.06 0.89 278 82.7 12,633

Rizor 44.93 15.82 0.88 252 83.1 11,80897HX704 43.46 15.76 0.8 204 84 11,524

Mean 48.01 15.79 0.79 217 84.2 12,731LSD (0.05) 2.15 0.54 0.06 64 0.8 671

149

TRANSGENIC SUGAR BEET VARIETY TESTING RESULTS



Introduction

Transgenic sugar beet varieties were evaluated against standard sugar beet varieties todetermine sugar yield potential. The transgenic sugar beet varieties have genes thatconfer resistance to the non-selective herbicides Liberty and Roundup. Parent varietiesof the transgenic sugar beet varieties were also included in the trial.

Methods

Four commercial varieties, two transgenic varieties, and the parent lines of thetransgenic varieties were evaluated in a trial conducted at the Malheur ExperimentStation, Ontario, Oregon. The commercial varieties evaluated included; AmericanCrystal ACH 211, Betaseed 8422, and Hilleshog Mono-Hy HM WSPM9 and HM WS91.The transgenic varieties and their parent lines were Beta Seed 8757 Liberty Link (LL)and 8757 and Hilleshog Mono-Hy HM 104 Roundup Ready (RR) and HM Pillar.

Varieties were planted in 4-row plots 23 feet long. Varieties were separated with 4-footalleys between plots and from adjacent plots by an unplanted row. The unplanted rowserved as a buffer to reduce the possibility of injuring non-resistant sugar beets whileapplying Roundup and Liberty herbicides to the resistant sugar beet varieties. Eachentry was replicated eight times in a randomized complete block experimental design.Sugar beet varieties were planted April 21 using a cone-seeder mounted on a JohnDeere model 71 Flexi-planter. After planting, the trial was corrugated and Counter 15 Gwas applied in a 7-inch band over the row at 6 oz/1000 ft of row.

Betamix Progress at 0.25 lb ai/acre and Poast at 0.10 lbs ai/acre were applied to allplots except the HM 104 Roundup Ready and the 8757 Liberty Link varieties. Roundupat 0.56 lb ai/acre was applied to plots planted with HM 104 RR, and Liberty at 0.26 lbai/acre was applied to plots planted with 8757 LL. Herbicide treatments were appliedMay 10, May 27, and June 5. The first application was made while sugar beets were atthe cotyledon to two-leaf stage of growth, and the last application was to 9-inch tallsugar beets. All treatments were applied at 20 GPA with CO2-pressurized backpacksprayer. Plots were cultivated May 23, May 29, and June 9. On May 23, sugar beetstands were thinned to one plant for every 7 inches of row. The study was sidedressedwith 242 lb/acre of N as urea on May 28. Weeds not controlled by herbicide treatments

120

were removed by hand as needed throughout the season.

Sulfur dust at 60 lb/acre was applied to the study by air on July 27 and August 28.Bayleton was applied at 1 lb/acre on July 31.

Sugar beets were harvested October 16. The foliage was removed by a flail beater andthe crowns clipped with rotating scalping knives. Roots were harvested from the centertwo rows of each plot using a single-row wheel-type lifter harvester. The combinedweights of sugar beets from both rows were used to calculate root yield. A sample ofeight beets was taken from each harvested row. The samples were coded and sent toHilleshog Mono-Hy research station in Nyssa, Oregon, for analysis.

Data were analyzed using ANOVA, and variety means were separated using aprotected least significant difference at the 5 percent level, LSD (0.05).

Results

A small percentage of the 8757 LL seed was not resistant to Liberty, so the first Libertyapplication was made to 2-leaf sugar beets, and then the beets were thinned to standafter non-resistant plants had died. The 8757 LL variety also had a small percentage ofbolters. The flowering stalks were removed from bolting plants weekly throughout theseason. The Roundup-resistant variety, HM 104 RR, had a distinctive growth patternearly in the season. Plants were healthy but the leaves appeared to grow morehorizontal to the soil. As the season progressed, the growth difference was lessapparent.

The HM 104 RR had the highest root yield, while its untransformed parent line, HMPillar had lower root yields than any other variety (Table 1). All other varieties hadsimilar root yields. The cultivar HM Pillar had the highest sucrose content while HM 104RR had among the lowest. Both transgenic cultivars, 8757 LL and HM 104 RR, wereamong the most productive based on the estimated yield of recoverable sugar per acre.

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Table 1. Root yields, sugar yields, and root quality data from sugar beet varieties inthe transgenic variety trial, Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

Company VarietyRootyield

Sugarcontent

Grosssugar Extraction

Estimatedrecoverable

sugar

ton/acre % lb/acre % lb/acre lb/ton

American Crystal ACH 211 41.53 16.39 13,610 90.6 12,331 297.1

Betaseed 8757 LL 43.37 16.59 14,386 90.58 13,030 300.5

8757 42.54 16.33 13,897 90.35 12,558 295.1

8422 41.44 15.98 13,238 89.92 11,902 287.3

Hilleshog Mono-Hy HM104 RR 45.58 15.88 14,484 89.81 13,011 285.3

HM WSPM9 43 16.04 13,789 91.08 12,558 292.1

HM WS91 42.52 16.13 13,713 90.93 12,468 293.2

HM Pillar 38.62 17 13,126 91.92 12,064 312.4

LSD (0.05) 1.69 0.29 561 0.47 525 6.5

Mean 42.33 16.29 13,780 90.65 12,490 295.4

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POSTEMERGENCE WEED CONTROL IN SUGAR BEETS



Introduction

Trials were conducted to determine the effect of application timing on Betamix andProgress herbicide treatments alone and in combinations with Upbeet and Stinger, andto determine if increased rates of Betamix and Progress could provide weed controlsimilar to lower rates applied at the earlier time.

Methods

Sugar beets were planted on May 2 on a 3-inch spacing in 22-inch rows. Counter CRwas applied over the row at 3.8 oz/1000 ft of row. Beets were sidedressed with 91 lbN/acre as urea on June 12. Postemergence herbicide treatments were applied startingat 2-leaf sugar beets on May 21.

Sequential herbicide applications were made approximately every 7 days. Comparisonswere made between treatments applied to 2-leaf sugar beets and those first appliedone week later to 4-leaf sugar beets. In addition, Betamix and Progress rates wereincreased in certain treatments to determine if increased rates would provide weedcontrol similar to lower rates applied a week earlier. For the herbicide application to2-leaf sugar beets, weeds were 0.25 to 1 inch tall. For the herbicide application to4-leaf sugar beets, weeds ranged from 1 to 4 inches tall. Plots were 7.3 wide by 30feet long. Treatments were broadcast with a backpack sprayer delivering 20 gpa at 30psi and were replicated four times. Weed control was evaluated visually June 28.Weed biomass was determined July 30.

Results

Betamix and Betamix Progress applied alone as repeated sequential treatmentsbeginning at 2-leaf sugar beets provided similar control of common lambsquarters,barnyardgrass, and hairy nightshade. However, Betamix alone provided greater controlof redroot pigweed than Progress alone. Redroot pigweed control was reduced whenStinger was added to Betamix. Barnyardgrass control was also reduced when Stingerwas tank mixed with Betamix or Progress. Redroot pigweed and hairy nightshadecontrol were generally lower when treatments were applied at the 4-leaf stage thanwhen applied at the 2-leaf stage. In all cases, increasing the rate of Betamix andProgress resulted in control similar to applications made to 2-leaf sugar beets. When

123

applied at the 2-leaf, stage, tank mixtures of Betamix with Upbeet plus Poast or Stingerplus Poast provided better redroot pigweed control than similar tank mixtures withProgress. When applied at the 4-leaf stage, redroot pigweed control was greater whenProgress (0.25 lb ai/acre) was combined with Upbeet than when it was combined withStinger. The reverse was true for hairy nightshade; the addition of Stinger to Progressprovided greater control than the addition of Upbeet. Biomass of commonlambsquarters was reduced by all herbicide treatments. With the exception of theProgress (0.25 lb ai/acre) plus Upbeet and Poast treatment applied at the 4-leaf stage,biomass of hairy nightshade was also reduced by all treatments. All treatmentsreduced redroot pigweed biomass. Progress plus Stinger and Poast applied at the4-leaf stage had higher pigweed biomass than any other herbicide treatment. Many ofthe other treatments applied at the 4-leaf stage also had higher biomass of redrootpigweed than the same treatments applied at the beginning at the 2-leaf stage, whichemphasizes the importance of timely herbicide applications in sugar beets .

Conclusions

As expected, weed control was greatest when sequential herbicide treatments werebegun early. When the initial herbicide application was delayed, triple the rate ofBetamix and Progress was required to provided control similar to sequentialapplications begun one week earlier.

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Table 1. Visual estimates of weed control on June 28 and weed biomass on July 30 insugar beets with sequential herbicide treatments, Malheur ExperimentStation, Oregon State University, Ontario, Oregon, 1997.

Weed control Weed biomass

Redroot Lambs- Barnyard- Hairy Redroot Lambs- Barnyard- HairyTreatment'

Rate Timing pigweed quarters grass nightshade pigweed quarters grass nightshade

lb ai/acre Leaves % g/ft2Betamix 0.33 2 86 95 73 88 1 0 2 0Progress 0.25 2 68 95 59 86 10 0 2 1Betamix + Upbeet 0.33 + 0.0156 2 95 95 93 90 0 0 0 1Progress + Upbeet 0.25 + 0.0156 2 91 95 94 85 1 0 0 1

Betamix + Stinger 0.33 + 0.047 2 74 95 45 95 3 0 3 0

Progress + Stinger 0.25 + 0.047 2 66 95 30 90 6 0 3 0Betamix + Poast 0.33 + 0.10 2 86 95 95 81 4 0 0 1Betamix + Poast 0.33 + 0.10 4 53 94 84 66 14 0 1 2Betamix + Upbeet + 0.33 + 0.0156 + 2 95 95 95 93 0 0 0 0Poast 0.10

Betamix + Upbeet + 0.33 + 0.0156 + 4 60 93 65 34 13 0 1 3Poast 0.10

Betamix + Upbeet + 1.0 + 0.0156 + 4 94 95 88 95 1 0 1 0Poast 0.10

Progress + Upbeet + 0.25 + 0.0156 + 2 86 95 95 95 1 0 0 0Poast 0.10



Betamix + Stinger + 0.33 + 0.047 + 2 85 95 94 95 2 0 0 0Poast 0.10



Progress + Stinger + 0.25 + 0.047 + 2 65 95 95 95 12 0 0 0Poast 0.10



Untreated 0 0 43 2 3 11LSD (0.05) 22 17 6 1 2 3

'Treatments first applied at 2 leaf sugar beets were applied-three times. Treatments first applied to 4 leaf sugar beets wereapplied twice.

125

"ON FARM" IMPLEMENTATION OF LOWER NITROGEN FERTILIZER INPUTSTHROUGH NITROGEN ACCOUNTING AND VALIDATION OF ORGANIC MATTER

MINERALIZATION

Clinton C. Shock, Erik B. G. Feibert, and Dale WestermannMalheur Experiment Station


Introduction

The objectives of this study were to examine the amount and importance of Nmineralized from soil organic matter in commercial sugar beet fields and to makeobservations of sugar beet plant N uptake in N fertilizer trials conducted by beetfieldmen in commercial fields to improve our understanding of beet responses to Nfertilizer.

Sugar beet nitrogen fertilizer guidelines are based on either fall or spring nitrate-Nlevels to 3-foot depth in the soil and total plant needs estimated at 8 lb N/ton of beets.These assumptions provide estimates for N fertilization which have been useful formany years. To make beet production and processing as efficient as possible, it isimportant to use only the N fertilizer needed to grow the crop. In the cases where soilorganic matter mineralization is large compared with residual soil nitrate or fertilization,the current guidelines could overestimate crop fertilizer needs.

When sugar beets receive N in excess of their needs, total beet yield and leaf growthare high, but both beet sugar content and total sugar yields can be depressed. Extranitrate and ammonium in the beet pulp reduce sugar factory efficiency.

Methods

Sugar beet fieldmen have conducting N fertilizer rate trials in growers fields during thelast few years. These trials have the basic structure of large plots with several N ratesand one to three replicates. In general the recommended N fertilizer rate is based onthe soil nitrate present in the soil profile to a depth of 3 feet in each field and a yieldgoal for that field. Other large field plots are treated with twice the recommended Nrate, half the recommended N rate, and no fertilizer as the check. In a some of thefields with high residual nitrate, the fieldman and grower opted to leave all plotsunfertilized. Ten fields were studied between Parma, Idaho, and Vale, Oregon, in 1996.Twelve growers' fields were studied through harvest in 1994 and an additional eightfields in 1995 between Brogan, Oregon, and Burley, Idaho (Table 1). Several otherfields were set up each year, but their experimental value was lost in cultivation orharvesting errors.

126

The growers took care of all of the cultural practices, and the fertilizers were applied incooperation with fertilizer industry representatives. Sugar beet fieldmen kept track ofcrop progress and coordinated the harvest, collecting data on yield and quality basedon the entire field plots. Beets were evaluated for total yield, tare, sucrose content,conductivity, and beet pulp nitrate by the Amalgamated Sugar Co.

Additional work was done by the Malheur Experiment Station. The percent sugarextraction and recoverable sugar were calculated based on empirical formulas. Soilsamples were collected in the spring for estimates of N mineralization via threemethods: anaerobic incubation, aerobic incubation, and the buried-bag method.Twelve to fourteen representative beets with their leaves and crowns were harvestedfrom each plot just before harvest then taken to the Malheur Experiment Station.Leaves and crowns were dried, weighed, ground, and analyzed for total N content. Thebeets were weighed fresh after the leaves and crown were removed, ground, and asubsample of the beet pulp was weighed wet, oven-dried to determine dry mattercontent, then analyzed for total N content. Beet N uptake per acre in the leaves,crowns, and beets was calculated based on the clean beet yield of each plot, the ratioof beet dry weight to fresh weight, the proportion of dry crown and leaf tissue to drybeet in the tissue samples, and the tissue sample N contents.

Total available soil N supply was calculated based on the sum of spring available nitrateand ammonium, any applied fertilizer N, and N mineralization (estimated by anaerobicincubation or seasonal N balance). Nitrogen use efficiency was calculated for each plotby dividing the total plant N uptake by the total available N supply for each plot andmultiplying by 100. Nitrogen mineralization was also estimated by aerobic incubationand buried bag methods.


Spring soil nitrate N ranged from 61 to 399 lb N/acre, depending on the field (Table 2).Optimistic yield goals ranging from 25 to 40 ton/acre of beets implied N fertilizer needsof 0 to 216 lb N/acre. The lowest applied N rates were 0 lb N/acre at twenty two of thethirty sites.

The 1994 season was favorable for high yields (Table 3), and all cooperating growerskept weeds and diseases under control. The 1995 season was far less favorable, withlower temperatures and cloud cover during the growing season. Repeated rainfallevents in 1995 made efficient N use difficult and reduced residual nitrate andammonium in the fields at harvest. Repeated hail during 1995 in the Treasure Valleywas damaging at certain locations. The 1996 season was more favorable.

The highest-yielding N fertilizer rates ranged from 0 to 205 lb N/acre depending on thefield studied. Sugar beet response to N fertilizer varied substantially. Reasonableyields were routinely obtained near Vale, Ontario, and Nyssa with low rates of Nfertilizer (Tables 2 and 3). Clear increases in beet yield and sugar production occurred

127

on shallow soils with irrigation apparently in excess of evapotranspiration. Beet pulpnitrate at 0 applied N suggested that there was excessive N supplies in many fields,even without any fertilizer nitrogen (Table 3). Beet petiole nitrate levels were consistentwith high yields at low N fertilizer inputs in these fields (data not shown).

The optimal N rate was determined independently for each field based on the highestyield of recoverable sugar. Beet plants at the optimal applied N levels contained 126 to439 lb N/acre at harvest depending on the field (Table 4). Anaerobic incubationestimates of N mineralization ranged from 88 to 285 lb N/acre, depending on the field(Table 5). Mineralized N appears to be a large N source averaging 163 lb N/acre overthe 20 fields (Table 4). Fields with high spring residual nitrate are not necessarily goingto have high rates of N mineralization; fields with low spring residual nitrate are notnecessarily going to have to low rates of N mineralization , r2 = 0.029, based on 1994and 1995 data.

In 1994, the anaerobic incubation estimates of mineralized N ranged in the same orderof magnitude as field method using N balance. The N balance method was based onmeasuring residual soil nitrate and ammonium at harvest and plant N content atharvest, then subtracting all known available N sources. The N balance was notcomparable in 1995, as would be expected after a season with untimely rainfall events.In 1996, fields with suspected heavy irrigation showed low available N balances. Theburied bag method of N mineralization was laborious and provided numbers similar andless than the anaerobic method. The aerobic method of soil incubation providedestimates of N mineralization in the same range as the anaerobic method, but thenumerical values were more erratic.

At the most productive N level tested at each site, sugar beets were able to recoverbetween 35.4 and 90.4 percent of the estimated total N supply (based on the sum ofsoil nitrate and ammonium to the 3-foot depth, fertilizer N, and N mineralization in Table4). The one efficiency of 125.7 percent occurred in a field irrigated with considerablenitrate in the irrigation water. Efficiencies less than 75 percent appear to be related tovery high N supply at 0 N applied, irrigations and rainfall in excess ofevapotranspiration, or sugar beet cyst nematode.

Conclusions

1. The mineralization of organic matter provided on average 163 lb N/acre per year, butthe fertilizer guides assume that only 30 to 50 lb N/acre will be mineralized.

2. Nitrogen fertilizer guides overestimated crop fertilizer needs. Nitrogen fertilizationwas of marginal benefit for sugar beets when nitrogen mineralization is high on deepsoils without excessive irrigation. In these studies, N fertilization was often counterproductive.

3. The anaerobic incubation method of estimating N mineralization was useful.

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Acknowledgments

These trials depended of the work of many growers and fertilizer fieldmen, withoutwhich the effort would have been impossible. We extend special appreciation to DelTraveler, Terry Tindall, Stacy Camp, Bill Walhert, and Bob Huffaker, Don Bowers, DaveElison, Steve Lund, Clark Millard, Bob Komoto, Monty Saunders, Saud Hafez, RayWinegar, Rod Faham, Al Scott, Lou Wettstein, and Terry Miller.

The financial support of the beet growers associations, Amalgamated Sugar, and theOregon Department of Agriculture is gratefully acknowledged.

129

Table 1. Characteristics of 20 sugar beet fields used for soil N mineralization studies in1994, 1995 and 1996, Malheur Experiment Station, Oregon State University,Ontario, Oregon.

SoilSoil organic Soil Planting Irrigation Previous

Field Location Soil texture pH matter depth Variety date system Comments crop1994 % feet

1 Burley sandy loam2 Minidoka silt loam

3 Minidoka silt loam4 Jerome loam5 Nyssa silt loam6 Ontario-Vale fine sandy loam

7 Ontario-Vale silt loam

8 Ontario-Nyssa fine sandy loam

9 Nyssa silt loam10 Vale silt loam

11 Brogan silt loam12 Ontario silt loam

1995

1 Buhl silt loam2 Burley silt loam

3 Rupert sandy loam4 Minidoka silt loam

5 Nyssa silt loam

6 Vale silt loam

7 Ontario silt loam

8 Nyssa silt loam

1996

1 Ontario silt loam2 Nyssa silt loam

3 Parma silt loam

4 Nyssa silt loam

5 Vale silt loam

6 Vale silt loam

7 Vale silt loam

8 Ontario silt loam

9 Ontario silt loam

10 Ontario silt loam

8.4 1.25 > 6

8 1.5 2.5

8 2.35 2.5

7.55 1.05 2.5

7.65 1.4 >67.5 1.6 >6

7.75 2.2 >67.4 1.75 >6

7.9 2.1 >6

7.6 2.05 >6

7.6 1.6 >67.6 1.5 >6

8.1 1.2 >6

8.1 1.49 2.5

7.8 1.28 >6

8.2 1.65 2.5

7.6 1.45 >6

7.8 3.29 >6

7.7 1.43 >6

7.4 1.47 >6

8.5 1.5 >6'7.8 1.7 >6'

8.0 2.2 >6'

7.7 1.4 >6'

8.0 1.4 >6'

8.0 1.4 >6'

8.0 1.3 >6'

7.8 1.2 >6'

7.8 1.5 >6'

7.8 1.5 >6'

MH 9455 April 11 side roll cyst nematode beets

PM-9 March 19 side roll rock at 2-3 wheat

WS 91 March 20 side roll rock at 2-3 wheat

WS 91 April 25 side roll rock at 2-3 potatoes

PM-9 last week March furrow onions

PM-9 March 7 furrow onions


PM-9 2nd week March furrow onions

PM-9 March 26 furrow B deficient potatoes


RSW-81 March 14 furrow onions

PM-9 April 5 furrow beans

PM-9 May 10 furrow beans

Beta April 10 side roll wheat8422

WS 62 April 20 furrow beans

PM-9 April 4 side roll potatoes

PM-9 March 30 furrow rhizoctonia onions

PM-9 furrow potatoes

PM-9 March 29 sideroll potatoes

PM-9 March 27 furrow rhizoctonia, beansflooding

furrow

furrow

PM-9 April 11 solid radish

furrow

WS 91 April 8 furrow onions



WS 62 March 19 furrow onions



130

Table 2. Optimistic yield goals, soil nitrate, recommended N fertilizer rates, grower'spreferred N fertilizer rates, and best fertilizer N rates for 1994, 1995 and1996, Malheur Experiment Station, Oregon State University, Ontario, Oregon.

Total N Recommended N Growers' Lowest N HighestOptimistic Soil needed for fertilizer for optimistic preferred rate used in yielding N

Field Location yield goal nitrate 0-3 optimistic yield yield goal N rate trial rate for theft goal trial

1994 ton/acre lb N/acre 1 Burley 28 164 224 60 80 0 402 Minidoka 35 171 280 109 110 0 1103 Minidoka 35 85 280 195 205 80 2054 Jerome 35 155 280 125 50 0 255 Nyssa 40 207 320 113 NA' 0 06 Ontario-Vale 40 284 320 36 75 0 07 Ontario-Vale 40 238 320 82 0 0 08 Ontario-Nyssa 40 148 320 172 NA 60 609 Nyssa 40 165 320 154 NA 60. 8010 Vale 40 356 320 -36 150 0 011 Brogan 35 165 280 115 100 0 012 Ontario 40 104 320 216 NA 0 0

1995

1 Buhl 25 199 200 1 100 0 02 Burley 25 61 200 139 160 80 1603 Rupert 35 95 280 185 120 19 1714 Minidoka 25 105 200 95 163 0 855 Nyssa 30 115 240 125 100 35 356 Vale 40 122 320 198 150 0 1507 Ontario 34 108 272 164 170 80 808 Nyssa 32 138 256 118 100 0 40

1996

1 Ontario 40 190 320 130 80 0 402 Nyssa 40 188 320 132 125 0 303 Parma 40 289 320 31 200 200 NA4 Nyssa 40 164 320 156 75 0 05 Vale 40 399 320 0 100 0 06 Vale 40 399 320 0 100 0 07 Vale 40 357 320 0 100 0 08 Ontario 40 254 320 56 100 0 09 Ontario 40 261 320 59 100 0 010 Ontario 40 261 320 59 100 0 0

*Boron deficient part of field.'NA: data not available.

131

Table 3. Beet yield and quality at, the best N rate for each of 20 growers' fields,Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1994,1995 and 1996.

Summary of characteristics Highest yielding plant performanceOptimistic Soil nitrate Most productive Clean beet Recoverable Pulp

Field Location yield goal 0-3' N rate for trial yield Sucrose Conductivity Extraction sugar nitrate1994 ton/acre lb N/acre lb N/acre ton/acre lb/acre ppm

1 Burley 28 164 40 24. 0 16.9 0.73 86.4 6,998 1872 Minidoka 35 171 110 35.5 18.1 0.73 86.5 10,799 1483 Minidoka 35 85 205 39.2 17.4 0.9 84.2 11,479 na4 Jerome 35 155 25 32.7 16.8 1. 00 82.8 9,064 4115 Nyssa 40 207 0 31.3 15.0 0.84 84.7 7,950 5526 Ontario-Vale 40 284 0 40.9 15.8 0.87 84.4 10,925 4837 Ontario-Vale 40 238 0 34.8 13.7 1.09 81 7,708 7018 Ontario-Nyssa 40 148 60 39. 0 16.7 0.68 87.1 11,342 2949 Nyssa 40 165 80 33.4 16.2 0.72 86.4 9,372 28310 Vale 40 356 0 38.3 14.8 0.98 82.7 9,406 58111 Brogan 35 165 0 29.4 14.9 0.95 83.1 7,280 62912 Ontario 40 104 0 45.6 16.2 0.75 86.1 12,732 175

1995

1 Buhl 25 199 0 21.3 16.9 0.60 88.1 6,352 1452 Burley 25 61 100 22.9 19.2 0.88 84.6 7,452 1783 Rupert 35 95 171 31.9 16.6 0.77 85.8 9,110 3134 Minidoka 25 105 85 21.4 16.6 0.62 87.8 6,787 1525 Nyssa 30 115 35 25.2 16.3 0.72 86.4 7,078 2436 Vale 40 122 150 31.4 14.9 1.06 81.6 7,630 6917 ' Ontario 34 108 80 28.0 17.6 0.64 87.7 8,649 1618 Nyssa 32 138 40 31.8 16.9 0.71 86.7 9,283 194

1996

1 Ontario 40 190 40 43.5 14.5 1.09 86 10,876 7392 Nyssa 40 188 30 36.9 16.6 0.74 86.3 10,572 3033 Parma 40 289 200 34.1 15.1 86 8,8564 Nyssa 40 164 0 33.5 15.4 1.02 84 8,667 5995 Vale 40 399 0 31.0 16.2 1.00 86 8,638 5466 Vale 40 399 0 31.0 16.1 1.00 86 8,585 5467 Vale 40 357 0 33.5 15.8 1.02 86 9,104 4818 Ontario 40 254 0 32.3 15.9 0.73 86 8,833 3439 Ontario 40 261 0 33.1 15.6 1.03 86 8,881 596

10 Ontario 40 261 0 29.8 15.5 0.99 86 7,945 576

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Table 4. Comparison of soil nitrogen supply, beet plant nitrogen content, and N useefficiency at harvest for beets grown at the highest-yielding N level in 20fields. Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1994, 1995 and 1996.

Best plantperformance N supply Plant N content

Field LocationBeetyield

Recoverablesugar

MostproductiveN rate for1994 trial

Springsoil

nitrate -N0-3 ft

Spring soilammonium

-N 0-3 ft

Estimate ofN-mineralization

(anaerobic)

TotalavailableN supply Leaves Crown Beets Total

Total plant Ncontent atharvest perton of beets

N useefficiency'

1994 ton/acre lb N/acre lb N/ton

1 Burley 24. 0 6,998 40 164 23 112 339 70 20 94 184 7.65 54.22 Minidoka 35.5 10,799 110 171 17 172 469 63 18 148 229 6.65 48.93 Minidoka 39.2 11,479 205 85 14 167 470 98 23 187 308 7.82 65.44 Jerome 32.7 9,064 25 155 16 135 331 103 15 145 263 8.07 79.55 Nyssa 31.3 7,950 0 207 64 88 359 127 18 150 295 9.42 82.36 Ontario-Vale 40.9 10,925 0 284 30 149 459 122 19 225 366 8.93 79.97 Ontario-Vale 34.8 7,708 0 238 32 251 520 162 17 197 376 10.87 72.48 Ontario-Nyss

a39 11,342 60 148 48 115 371 111 23 180 314 8.06 84.6

9 Nyssa 33.4 9,372 80 165 31 97 373 87 27 129 243 7.26 65.110 Vale 38.3 9,406 0 356 39 236 631 165 35 226 426 11.06 67.511 Brogan 29.4 7,280 0 165 48 224 2 437 2 100 37 164 301 10.08 68.9 2

12 Ontario 45.6 12,732 0 104 49 292 2 445 2 123 46 226 395 8.65 88.8 2

19951 Buhl 21.3 6,352 0 199 NA' 95 294 88 8 78 174 8.20 59.22 Burley 22.9 7,452 100 61 17 158 336 79 5 65 149 6.50 44.43 Rupert 31.9 9,110 171 95 NA 195 461 92 9 116 217 6.79 47.14 Minidoka 21.4 6,787 85 105 NA 130 320 52 6 77 135 5.80 42.25 Nyssa 25.2 7,078 35 115 34 121 305 52 4 70 126 5.00 41.36 Vale 31.4 7,630 150 122 27 210 509 130 13 112 255 8.10 50.17 Ontario 28.0 8,649 80 108 24 189 401 55 9 98 162 5.80 40.48 Nyssa 31.8 9,283 40 138 30 136 344 72 8 136 216 6.80 62.8

19961 Ontario 41.8 10,568 40 190 14 141 346 129 53 265 439 10.40 125.72 Nyssa 36.9 10,572 30 188 27 130 375 80 33 193 306 8.30 81.43 Parma 34.1 8,856 200 289 11 172 672 109 47 185 341 10.10 50.94 Nyssa 33.5 8,667 0 164 42 125 331 84 50 170 304 9.10 91.75 Vale 31.0 8,638 0 399 46 285 730 80 43 135 258 8.30 35.46 Vale 31.0 8,585 0 399 46 253 698 91 31 170 294 9.50 42.17 Vale 33.5 9,104 0 357 42 177 576 54 31 138 223 6.70 38.78 Ontario 32.3 8,833 0 254 36 111 401 84 100 179 363 11.20 90.49 Ontario 33.1 8,881 0 261 43 144 448 120 40 201 361 10.90 80.710 Ontario 29.8 7,945 0 261 43 93 397 92 52 192 336 11.30 84.9

'Total plant N content as a percent of the total available N supply.2N mineralization estimate by season-long N balance.NA: data not available.

133

Table 5. Estimates of N mineralization made in 30 growers' sugar beet fields by twodifferent methods, Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1994, 1995, and 1996.

N-mineralization estimate

Grower Organic Anaerobic AvailableLocation Soil texture matter incubation nitrogen balance

1994 OA - - lb N/acre - -1 Burley sandy loam 1.25 112 NA

2 Minidoka silt loam 1.5 172 NA

3 Minidoka silt loam 2.35 167 NA

4 Jerome loam 1.05 135 283

5 Nyssa silt loam 1.4 88 238

6 Ontario-Vale fine sandy loam 1.6 149 238

7 Ontario-Vale silt loam 2.2 251 304

8 Ontario-Nyssa fine sandy loam 1.75 115 1259 Nyssa silt loam 2.1 97 61

10 Vale silt loam 2.05 236 251

11 Brogan silt loam 1.6 149 224

12 Ontario silt loam 1.5 159 293

1995

1 Buhl silt loam 1.2 95 NA

2 Burley silt loam 1.49 158 -11

3 Rupert sandy loam 1.28 195 12

4 Minidoka silt loam 1.65 130 3


6 Vale silt loam 3.29 210NA



1996



3 Parma silt loam 2.2 172 -28

4 Nyssa silt loam 1.4 125 -43

5 Vale silt loam 1.4 285 -13






134

1997 SMALL GRAIN VARIETY TRIALS

Eric P. Eldredge, Clinton C. Shock, and Russell S. KarowMalheur Experiment Station


Introduction

The purpose of these trials was to evaluate the performance of small-grain cultivarsunder local cultural practices and environmental conditions. Data obtained from thesetrials help local growers choose grain varieties. The data also provide public andprivate plant breeders with site-specific performance for advanced lines and newlyreleased varieties.

Six small grain variety trials were conducted at the Malheur Experiment Station duringthe 1996-97 crop year. The OSU statewide winter cereal, winter barley, spring cereal,and spring barley trials were conducted as part of a statewide small-grain variety testingprogram. For the sixth year, a fall-planted, fall-emergence and fall-planted,winter-emergence wheat trial was conducted at the Malheur Experiment Station. Thepurpose of the trial was to provide local growers with information on the yield of lateplanted winter types compared to spring types.

Methods

All winter trials and spring trials were planted in randomized complete-block designswith three replications. Each plot was planted on a 56-inch bed with seven rowsspaced 7 inches apart on each bed. The dimensions of each plot were 56 inches wideby 20 feet long. All trials were furrow irrigated. In early July, 42 inch alleys were cut fromeach plot, leaving a harvestable plot length of 16.5 feet. After the varieties had matured,samples were harvested using a plot combine to cut each plot, an area of 77 ft2 . Allsamples were cleaned, then test weight and protein content were measured at OregonState University Cereals Laboratory, Corvallis.

Winter Trials. The 1996-97 winter cereal trials followed the 1996 harvest of sweet corn.No preplant fertilizer was applied. The OSU statewide winter cereal, OSU statewidewinter barley, and the fall-planted, fall-emergence wheat trials were planted October 23,1996. Seed was drilled approximately 1 inch deep. The seeding rate for the OSUstatewide winter cereal trial and the OSU statewide winter barley trial was 30 seeds/ft2.The seeding rate for the fall-planted, fall-emergence wheat was 120 lb/acre.

135

The fall-planted, winter-emergence wheat trial was planted at 120 lb/acre on December16, 1996. The planting procedure was the same as for the fall-planted trials describedabove.

On May 28, 1997, the winter cereal plots were top-dressed with 60 lb/ac N as ureaprills. To control broadleaf weeds, Bronate at 1 qt/acre in 40 gpa of water was appliedby ground-rig over the winter trials on May 5, 1997.

The winter grain variety trials were furrow irrigated on May 6, May 30, and June 12. Thewinter grain trials were harvested on July 31 and August 1, 1997. Grain yield per acrewas calculated based on a plot length of 16.5 feet and a swath width of 56 inches.

Spring Trials. The 1997 spring cereal trials were grown in the same field as the wintertrials, following sweet corn, with no preplant fertilizer. All entries in the OSU statewidespring cereal trial and the OSU statewide spring barley trial were drilled approximately 1inch deep into moist soil on March 28,1997. The seeding rate for both plantings was 30seeds/ft2 . The field was sprinkler irrigated April 14 to ensure uniform germination.

On April 7, Bronate at 1 qt/acre in 30 gpa of water was applied by ground-rig over bothtrials, and on April 12 the field was re-corrugated. On May 23 both spring trials weretop-dressed with 63 lb/ac N as urea prills. The field was irrigated on May 12, 23, andJune 12.

The spring barley trial was harvested August 4, 1997, and the spring cereal trial washarvested August 5, 1997. Grain yield per acre was calculated based on a plot length of16.5 feet for both trials. Variety performance was compared in each trial using ANOVAand protected least significant differences (LSD) test.


1996-97 Winter Cereal Grain Trials. Good seedling emergence was achieved. Weatherduring November was unusually dry. Fall planted grain developed more than usual,resulting in many tillers late in winter and early spring. The well-developed plantshelped provide the basis for high yields in 1997.

The OSU statewide winter cereal trial included 20 soft white winter wheats, one hardred winter wheat, seven winter club wheats and four winter triticales (Table 1). Yieldsfor the soft white cultivars ranged from 133 bu/acre for Hybritech 1020 to 40 bu/acre forTrical 102. Test weights for the soft whites ranged from 62.1 Ib/bu for ID86-10420A to58.0 Ib/bu for Stephens. Protein for the soft white cultivars ranged from 11.5 percent

136

for Gene and OR880172 to 9.2 percent for Malcolm. The average heading date (50percent headed) for the trial was May 11. Heading dates for soft white wheat cultivarsranged from May 11 for nine of the soft white winter wheats to May 22 for Hybritech1017. At Maturity, plant heights within the soft whites ranged from 41 inches forID86-10420A to 32 inches for ID14502B. Lodging was observed mostly in the triticaleand varieties bordered on the north side by triticale.

The OSU statewide winter barley trial included 10 six-row feed barley entries and onesix row dual use feed or malt variety (Table 2). Yields ranged from 6421 lb/ac forStrider to 4063 lb/ac for Steptoe. Test weights ranged from 53.4 Ib/bu for ORW10 to50.1 Ib/bu for the variety Steptoe. Protein levels ranged from 10.5 percent for 81019-11to 8.5 percent for Steptoe. The average heading date (50 percent headed) for thenursery was May 11. Heading dates ranged from May 9 for Gwen to May 11 forSteptoe. At maturity, plant height ranged from 43 inches for Steptoe to 31 inches for81019-11. Lodging was insignificant for all winter barley entries in 1997.

Both the fall-planted fall-emergence wheat trial and the fall-planted winter-emergencewheat trial included the same five soft white spring wheats, three soft white winterwheats, and two hard red spring wheat cultivars (Table 3). Yields in the fall-emergencetrial ranged from 124 bu/acre for MacVicar to 83.5 bu/acre for Anza. At harvest nodifferences in lodging were observed.

In the winter-emergence trial, yields ranged from 117 bu/acre for Malcolm to 85.6bu/acre for Penewawa. The yields of Penewawa, Pomerelle, Stephens, Malcolm, andMacVicar were among the highest when planted on October 23, with MacVicar yieldingsignificantly more than the average of the fall emergence group. Yields of Treasure,Pomerelle, Centenial, Yolo, Stephens, Malcolm and MacVicar were not significantlydifferent from one another or the average when those varieties were planted onDecember 16 and emerged during the winter months.1997 Spring Cereal Grain Trials. Yields for the soft white types in the OSU statewidespring cereal trial ranged from 130 bu/acre for ID488 to 96 bu/acre for Wawawai (Table5). Yields for the hard red types ranged from 104 bu/acre for WPB936R to 90 bu/acrefor WA7802. The yield for the triticale TriCal 2700 was 82 bu/acre. Test weights for thesoft white spring wheats ranged from 63.8 Ib/bu for ID488 to 60.7 Ib/bu for Pomerelle.Test weights for the hard red cultivars ranged from 64.5 Ib/bu for ID377S to 62.6 Ib/bufor Yecora Rojo. Heading dates (50 percent headed) for the soft white wheats rangedfrom June 8 for Centennial to June 12 for Treasure. Heading dates for the hard redtypes ranged from June 7 for ID462 to June 11 for Yecora Rojo and WA7802. Atmaturity, plant heights for the soft white cultivars ranged from 34 inches for Alpowa,Penewawa, and Centenial to 39 inches for Wawawai. No lodging was observed amongany of the entries in this trial.

137

The OSU statewide spring barley trial included nine feed, seven malting, one hullessand one hooded cultivars (Table 6). Yields ranged from 6,740 lb/acre for Idagold to4,004 lb/acre for Bear. Test weights ranged from 58.7 Ib/bu for Bear (a hulless barley)to 42.9 Ib/bu for Washford (a hooded barley). Idagold was the highest yielding feedbarley at 6740 lb/acre, and lowest feed barley yield was 78AB10274 at 4572 lb/acre.Malting barley yields ranged from 6429 lb/acre for Galena to 4363 lb/acre for Crest.Test weight in the feed cultivars ranged from 53.6 Ib/bu for Gallatin to 49.6 Ib/bu forSteptoe. The test weights of the malting barleys ranged from 53.7 Ib/bu for Orca to 51.0Ib/bu for Crest. The average heading date (50 percent headed) for the trial was June10. Heading dates ranged from June 6 for Steptoe to June 13 for Idagold. At maturity,plant heights ranged from 26 inches for Idagold and UC960 to 37 inches for Washford.Washford was severly infected by smut at this location.

138

Table 1. Yield, test weight, protein content, plant height, and heading date of winterwheats and triticales, Malheur Experiment Station, Oregon State University,Ontario, OR, 1997.

Variety Marketclass

YeildTest

weight ProteinPlantheight

Headingdate

bu/acre Ib/bu inches May

Hybritech 1020 SW 133 59.4 10.1 37 19STN Raxil SW 131 58.9 9.9 36 11STN Vitavax+Gaucho SW 127 58.6 10.6 35 11STN Dividend SW 127 60.1 10.6 37 11Rohde CLUB 124 61.3 10.3 33 19Hiller CLUB 124 58.3 9.6 38 21Gene SW 124 61.4 11.5 34 17OR870012 SW 119 59.7 10.8 35 11ID 467 HR 119 60 9.9 37 17RS87123 TRITICALE 117 57.6 9.3 46 10Rod SW 117 60.7 9.6 34 20Madsen SW 117 60.8 10 35 19Hybritech 1019 SW 116 62 10.7 35 13RS87202 TRITICALE 114 57.8 9.6 42 11Rely CLUB 111 61.1 10.7 37 19Malcolm SW 111 60.4 9.2 35 191D86-10420A SW 111 62.1 10 41 19W301 SW 109 59.5 10.1 35 11ID14502B SW 109 59.3 10.3 32 11ORCL0049 CLUB 108 56.9 9.2 32 20WA7752-Allan CLUB 107 59.5 9 37 21OR898120 SW 107 61.3 10.6 36 21Stephens SW 106 58 9.8 35 11ORCL0054 CLUB 106 60.1 11 34 11Madsen+Stephens SW 104 58.8 10.2 34 11Hybritech 1017 SW 104 59.4 10.1 39 22RS87183 TRITICALE 102 58.1 9 43 11MacVicar SW 100 60.6 10 35 11WA7793-Allan CLUB 94 57.1 10.1 36 21OR880172 SW 90 59.2 11.5 39 20OR870082 SW 82 59.8 10.5 33 19Trical 102 TRITICALE 40 55.7 10.6 54 10LSD (0.05) 24.7 2.21 1.26Mean 109.7 59.48 10.14 37 16

139

Table 2. Yield, test weight, protein content, plant height, and heading date of winterbarleys, Malheur Experiment Station, Oregon State University, Ontario, OR,1997.

VarietyMarketclass

YieldTest


Headingdate

lb/ac Ib/bu inches MayStrider 6RF 6,421 50.9 10 40 1081019-8 6RF 6,377 51 9.7 33 1081019-11 6RF 6,289 51.1 10.5 31 11Scio 6RF 6,249 51.4 9.1 35 1081019-10 6RF 5,953 51.4 10.2 34 11ORW10 6RF/M 5,776 53.4 10.1 35 9Gwen 6RF 5,566 53 9.2 40 9Steptoe-Bayton-Other 6RF 5,161 50.6 9.1 43 11Kold 6RF 5,154 52.5 9.9 36 11ORW11 6RF 4,208 52 9.8 37 10Steptoe 6RF 4,063 50.1 8.5 43 11LSD (0.05) 1,342 0.74 1.25MEAN 5,565 51.58 9.66 37 10

Table 3. Yield of spring and winter types of wheats planted to emerge in either fall orwinter, Malheur Experiment Station, Oregon State University, Ontario, OR,1997.

Variety Market class

YieldFall emerged Winter emerged

bu/acrePenewawa SWS 108.2 85.6Treasure SWS 100.8 115.1Pomerelle SWS 107.8 105.4Alpowa SWS 88.4 91.6Centenial SWS 91.5 105.7Yolo HRS 104.3 110.7Anza HRS 83.5 89.1Stephens SWW 112.1 108.6Malcolm SWW 122.2 116.7MacVicar SWW 124.4 114.6Mean 104.3 104.3LSD (0.05) 19.8 17.2

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Table 4. Yield, test weight, protein content, plant height, and heading date of springbarleys. Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1997.

Variety

YieldTest


Headingdate

Marketclass lb/ac Ib/bu 0/0 inches June

Idagold 2RF 6740 51.6 8.0 26 13Galena 2RM 6429 51.8 8.0 31 12Orca 2RM 6316 53.7 9.9 34 8Moravian 14 2RM 6316 53.4 8.9 27 10Colter 6RF 6158 50.0 8.2 35 7C-22 2RM 6093 51.2 7.7 33 11UC960 2RF 5728 47.6 9.2 26 7Russell 6RM 5722 52.1 9.3 33 9Baronesse 2RF 5691 52.9 8.3 31 11Steptoe+Baytan 6RF 5674 50.3 9.0 31 6Gallatin 2RF 5663 53.6 8.0 34 11Chinook 2RM 5407 53.1 9.3 35 11Steptoe+Vitavax 6RF 5281 49.6 9.0 33 6Payette 6RF 4927 50.9 8.8 31 10Washford 6R hooded 4626 42.9 9.7 37 1178AB10274 2RF 4572 50.6 9.6 32 11Crest 2RM 4363 51.0 9.1 35 9Bear 6R hulless 4004 58.7 9.5 34 12LSD (0.05) 1580 2.76 0.69Mean 5539 51.38 8.86 32 10

141

Table 5. Yield, test weight, protein content, plant height, and heading date of springwheats and triticales. Malheur Experiment Station, Oregon State University,Ontario, Oregon, 1997.

VarietyMarketclass

YieldTest


Headingdate

bu/acre lb/bu % inches JuneID488 SW 130 63.8 9.1 35 10Whitebird SW 115 63.1 9.4 37 9Alpowa SW 111 63.5 8.3 34 10Penawawa SW 110 62.7 8.5 34 8Centennial SW 106 63.3 8.8 34 8Treasure SW 105 61.9 8.8 36 12ID377S HW 105 64.5 9.5 37 13WPB936R HR 104 64.1 11.3 32 9Pomerelle SW 103 60.7 8.8 36 9Klasic WA7802 HW 103 63.7 11.0 26 11Alpowa noGaucho SW 102 63.3 8.7 34 11ID492 HR 98 64.2 10.2 36 10Wawawai SW 96 63.7 9.0 39 9OR4870453 HW 96 62.5 9.7 30 9ID462 HR 94 63.1 11.1 35 7Yecora Rojo HR 93 62.6 11.3 26 11WA7802 HR 90 63.0 11.0 39 11OR4895181 HW 90 61.4 9.8 34 7Trical 2700 TRITICALE 82 56.8 8.3 55 7LSD (0.05) 13.9 1.06 0.66Mean 101.7 62.74 9.61 35 10

142

IMPROVED NITROGEN AND IRRIGATION EFFICIENCYFOR WHEAT PRODUCTION

Clinton C. Shock, Eric P. Eldredge, and Lamont SaundersMalheur Experiment Station


Summary

Management alternatives to reduce N fertilizer and to lessen irrigation amounts weretested for furrow irrigated wheat in replicated half acre plots. The recommended Nfertilizer rate and 40 percent of the recommended N fertilizer rate were tested underconventional furrow irrigation (continuous) and surge irrigation. With the recommendedN rate, wheat yielded 113.4 bu/acre averaged over both irrigation methods, significantlymore yield than the 99.8 bu/acre obtained at the 40 percent N rate. Surge irrigationrequired only 13.4 acre-inch/acre of water compared to 25.4 acre-inch/acre forconventional furrow irrigation, while yields were not significantly less: 104.3 bu/acrecompared to 108.9 bu/acre averaged over both N rates.

Introduction

Previous small plot research at the Malheur Experiment Station has demonstrated theeffectiveness of using greatly reduced application of nitrogen fertilizer for optimumwheat production.

Surge irrigation is a tool that can be used to improve the efficiency of water applied byfurrow irrigation. In surge irrigation, water is applied to an irrigation furrow intermittentlyduring an irrigation set, whereas in continuous-flow (or conventional) irrigation, water isapplied to the furrow during the entire irrigation set. With surge irrigation, an automatedswitching valve, commonly referred to as a surge valve, is used to repeatedly cyclewater from one half of the field to the other half. Total water application can be reducedsubstantially with the use of surge irrigation. Previous research at the MalheurExperiment Station with wheat, onions, potatoes, and sugar beets has demonstratedthe effectiveness of surge irrigation in reducing water applications while maintainingcrop yield and quality equivalent to conventional furrow irrigation.

The reduced water applications with surge irrigation could result in a reduction of nitrateleaching and adjustment in N fertilizer practices. This trial compared wheat productionwith moderate and reduced N inputs under either conventional furrow irrigation or surgeirrigation in field scale strip plots. Strip plots were 0.5 acres each with 620-foot longirrigation runs. The objective was to investigate the interaction between reduced

143

nitrogen fertilizer and reduced water inputs on crop yield and quality with a field lengthrelevant to furrow irrigated agriculture.

Methods

The 1997 trial was conducted on a Greenleaf silt loam previously planted to sugarbeets at the Malheur Experiment Station. The field was disked, ripped, plowed andgroundhogged in the fall of 1996 following sugar beets. Each plot was sampled in1-foot increments to six-foot depth in three locations corresponding to the top, middle,and bottom of the plot. At each location the soil samples for the top two feet of soilconsisted of 20 subsamples and below the second foot the sample consisted of fourGiddings probe holes at 1-foot increments. The field was groundhogged, 120 lb/acrePenewawa spring wheat was drilled and bedded into 30-inch centers on March 24,1997. A soil sample showed a pH of 7.7, 1.1 percent organic matter, 18 meq/100 g ofsoil cation exchange capacity.

The experimental design had the irrigation and nitrogen fertilizer rates arranged in arandomized complete block factorial design replicated three times. The plots were 36feet wide and 620 feet long. Treatments consisted of two fertility levels and twoirrigation methods (Table 1). The amount of fertilizer to be applied to each fertilizedplot was based on late March soil samples at 0 to 2 foot depth at 100 percent of therecommended N rate and 40 percent of the recommended rate (Gardner et al. 1985).The 100 percent recommended rate consisted of applying approximately 115 lb N/acrefor a total N supply (soil NO 3-N + NH 4-N in the 0 to 2 foot depth plus fertilizer N) of 200lb N/acre. The N was applied as broadcast urea.

Gated pipe was arranged to permit all 12 plots to be irrigated simultaneously. A surgevalve (Waterman, Model LVC-5) automatically oscillated water from three of the surgeirrigation plots to the other three surge irrigation plots. The valves on the gated pipewere adjusted to deliver the same flow rate to all furrows in the surge and in theconventional irrigation systems. The field was irrigated on May 8, May 22, June 2, andJune 25.

To estimate sediment losses, water inflow, water outflow, and net infiltration, anobjective measurement and calculation method was used (Shock and Shock, 1997).Onset times of water inflow and outflow, and interval measurements of water inflowrate, water outflow rate, and sediment yield were recorded during each irrigation.

For each water outflow reading, a 1-liter sample was placed in an Imhoff cone andallowed to settle for 15 minutes. Sediment content in the water, in g/I, was found to berelated to the Imhoff cone reading (x) after 15 minutes by the equation

y = 1.015x with r2 = 0.98 and p < 0.0001.

144

Total inflow, outflow, infiltration, and sediment loss were integrated from fieldmeasurements using a Lotus Improv program, "InfilCal" (Shock and Shock, 1995). TheInfilCal program utilizes simple approximations of the integrals of inflow rates, outflowrates, and sediment content over time to estimate the inflow, outflow, and sedimentloss. Each flow rate reading and Imhoff cone sediment sample is taken to berepresentative of the interval of time closest to the reading. In other words, if readingsand sediment samples are taken at times t t n , and tni. l , the flow rate reading andn-1) nt

sediment sample at time t o are taken to be representative of the interval of time fromtn_i-Ftn+1

2

to

tn+t„+i2

The estimated inflow volume for the interval about t o is therefore given by

InflowVolume(tn)–(41+14"-')InflowRate(tn)2

where InflowRate(tn) is the measured inflow rate at time t n . The outflow volume is givenby the same equation, replacing the inflow rate with the outflow rate. The estimatedsediment loss for the interval about t o is given by

SedLoss(tn )= OutflowVolume(tn)Content(tn)

where Content(t n) is the sediment content given by the above Imhoff cone method.Although measurements should be taken on an established schedule, the time intervalsbetween measurements need not be constant.

Clearly, this method must account for the time between onset and the firstmeasurement and, likewise, between the last measurement and shutoff. The inflowrate value at the time of onset is taken to be the same as the first inflow ratemeasurement after onset, and the value at the time of shutoff is taken to be the sameas the last inflow rate measurement before shutoff. The outflow rate value at the timeof onset is taken to be zero, as is the outflow rate at the end of the irrigation. Each ofthese values applies to the first half of the time interval between onset and the firstmeasurement, or to the last half of the time interval between the last measurement andshutoff.

Strips were harvested July 28 with a Hege plot combine at the top, middle, and bottomof each strip. A 9 ft2 area was harvested in the top, middle, and bottom tiers of eachstrip to determine stubble yield and grain-to-stubble ratio. Stubble and grain wereground and analyzed for total N.

145

After harvest, between August 26 and 28,1997, the soil from each plot was sampled tosix-foot depth in one-foot increments in the top, middle, and bottom of each 620 footstrip as it had been before planting.

The available N balances were calculated by subtracting the N supply (available soil Nin spring plus fertilizer N) from the postharvest accounted N (crop N uptake plusavailable soil N after harvest).

Treatment differences in irrigation, infiltration, runoff, sediment loss, crop yield andquality, and nitrogen recovery were compared using analysis of variance and theprotected least significant difference test at the five percent level, LSD (0.05).


Conventional furrow irrigated plots required 4 irrigations totaling 132 hours, and surgeirrigated plots required 4 irrigations totaling 132 hours ire order to maintain the soiladequately wet for wheat growth and development. The actual duration of waterapplications with surge irrigation were half of that for conventional irrigation. Actualwater applications were 132 hours for conventional irrigation and 66 hours for surgeirrigation resulting in a 45 percent reduction in applied water (Table 1). Infiltration wasvery high in this field, which resulted in low levels of run off and low levels of sedimentloss.

The wheat fertilized at the full recommended rate (115 lb N/acre) was 13 percent moreproductive than wheat that received only 40 percent of the recommended N rate (Table2). Conventional furrow irrigation was 4.6 bu/acre more productive than surge irrigation(difference not statistically significant) with almost twice the applied water.

The soil N balance was not influenced by the treatments (Table 3). The N balanceswere all positive, suggesting a substantial N contribution from organic mattermineralization.

Literature Cited

Gardner, E.H., T.L. Jackson, B.C. Willcox, R. Todd and L. Fitch. 1985. Fertilizer Guidefor Irrigated Spring-planted Small Grains on Mineral Soils east of the cascades (FG37),Oregon State University Extension Service.

Shock, B.M. and C.C. Shock. 1995 (Copyright 1988, 1989, 1993, 1995). InfilCal 5.0.

Shock, C.C. and B.M. Shock. 1997. Comparative effectiveness of polyacrylamide andstraw mulch to control erosion and enhance water infiltration. p. 429-444. In Wallace, A.(ed.) Handbook of soil conditioners, Marcel Dekker, Inc. New York, NY.

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Table 1. Effect of furrow irrigation method on the water applied, runoff, infiltration, andsediment loss in a field of Penewawa spring wheat during four irrigations,Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1997.

Furrow irrigation Total sedimentmethod

Net water movements by irrigation lossacre-inch/acre lb/acre

May 8 May 22 June 2 June 25 TotalConventional

49.5Applied 8.8 4.2 6.8 4.7 24.5Runoff 0 0 0.8 0.8 1.6Infiltration 8.8 4.2 6.0 3.9 22.9

Surge 19.6Applied 4.3 2.8 3.9 2.5 13.4Runoff 0.3 0 0.2 0.2 0.7Infiltration 4.0 2.8 3.7 2.3 12.7

LSD (0.05)

27.4Applied 0.33 1.22 2.09 0.47 3.1Runoff NS NA NS 0.40 NSInfiltration 0.43 1.22 1.82 0.44 2.9

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OA) lb/ac

Table 2. Influence of N rate and surge irrigation on the yield and quality of Penewawaspring wheat, Malheur Experiment Station, Oregon State University, Ontario,Oregon, 1997.

Treatment Wheat response

Furrow irrigation N fertilizer Yield Harvest Grain Straw Straw NSmethod rate (60 lb/bu) index protein yield content

lb/acre bu/acre

Continuous 115 117.9 58 13.1 5603 0.781

Continuous 44 100.0 57 12.2 4832 0.530

Surge 115 108.8 59 14.5 4581 0.701

Surge 44 99.6 58 12.4 4217 0.546

LSD (0.05) Irrigation NS NS NS 815 NS

LSD (0.05) N rate 8.7 NS 1.1 NS 0.044

LSD (0.05) Irrig. x N NS NS NS NS 0.062

Table 3. Influence of N rate and furrow irrigation method on wheat N uptake and theavailable nitrogen accounting, Malheur Experiment Station, Oregon StateUniversity, Ontario, Oregon, 1997.

Pre-plant Fall soil Plant N at harvestBalance

Furrow N soil avail. NbasedStraw N Grain N Total N Total on 0-2'

irrigation fertilizer available Fertilizer (0-2') accountedrecovery recovery recovery depthmcthod rate N 0 2' N Total- N lb n/acre

Cont. 115 91 115 206 62 42 165 207 269 63

Cont. 44 86 44 130 55 26 133 159 214 84

Surge 115 79 115 196 65 33 163 196 261 67

Surge 44 95 44 139 62 23 119 142 204 65

LSD (0.05) Irrig. NS -- NS NS NS NS NS NS NS

LSD (0.05) N rate NS 6 NS 7 29 33 32 NS

LSD (0.05) I x N NS 9 NS NS NS NS NS NS

Treatment N Supply Fall nitrogen accounting

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HERBICIDES AND ADJUVANTS

Trade Name

AxiomBalanceBanvelBetamixBronateBuctrilClarityCobraDual, Dual II, Dual Magnum IIEptamEradicaneFrontierGoalHarnessLassoLibertyMatrixMicro-TechPartnerPoast, Poast HCProgress

ProwlRoundup UltraSelect, PrismSencorSonalanStingerSurpassTreflanUpbeetWeedar 64Weedone 638Weedone LV-4

Common or Code Name

FOE-5043 + metribuzinIsoxaflutoledicambadesmedipham + phenmediphambromoxynil + MCPAbromoxynildicambalactofenmetolachiorEPTCEPTC + safenerdimethenamidoxyfluorfenacetochlor + safeneralachlorglufosinaterimsulfuronalachloralachlorsethoxydimdesmedipham + phenmedipham

ethofumesatependimethalinglyphosateclethodimmetribuzinethalfluralinclopyralidacetochlor + safenertrifluralintriflusulfuron2,4-D amine2,4-D ester + acid2,4-D ester

Manufacturer

BayerRhone-PoulencBASFAgrEvoRhoune-PoulencRhone-PoulencBASFValentNovartisZenecaZenecaBASFRohm and HaasMonsantoMonsantoAgrEvoDupontMonsantoMonsantoBASF

AgrEvoAm. CyanamidMonsantoValentBayerDowDowZenecaDowDupontRhone-PoulencRhone-PoulencRhone-Poulenc

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INSECTICIDES, FUNGICIDES, AND NEMATICIDES

Trade Name Common or Code Name Manufacturer

Admire imidacloprid BayerBayleton triadimefon BayerBenlate benomyl DuPontCaptan captan Micro FloCounter CR, Counter 15G terbufos Am. CyanamidDithane mancozeb Rohm and HaasKocide copper hydroxideLannate methomyl DuPontLorsban chlorpyrifos DowMalathion malathion UAPRidomil M2 metalaxyl NovartisRotenone rotenoneTelone C-17 dichlopropene + chloropicrin DowWarrior cyhalothrin Zeneca

150

Common and scientific names of crops

Common names Scientific namesalfalfaasparagusbarleycornhickii yewhoney boat squashonionpoplar treespotatosoybeanssupersweet cornsweet corntriticalewheat

Medicago sativaAsparagus officinalisHordeum vulgareZea maysTaxus mediaCucurbita maximaAllium cepaPopulus deltoides x P. nigraSolanum tuberosumGlycine maxZea maysZea maysTriticum x SecaleTriticum aestivum

Common and scientific names of weeds

Common names Scientific namescommon lambsquartersgreen foxtailredroot pigweedbarnyardgrasskochiahairy nightshade

Chenopodium albumSetaria viridisAmaranthus retroflexusEchinochloa crus-galliKochia scopariaSolanum sarrachoides

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Malheur Experiment Station Annual Report, 1997 - … · Wettstein, Lou Willison, Greg Beef...

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