Effect of Winter Annual WeedEffect of Winter Annual Weed ... · Nematode Population and...
Transcript of Effect of Winter Annual WeedEffect of Winter Annual Weed ... · Nematode Population and...
Effect of Winter Annual WeedEffect of Winter Annual Weed Management on Soybean Cyst
Nematode Population and WeedNematode Population and Weed Density
Valerie A. Mock J. Earl Creech William G. Johnson
Soybean Cyst Nematode (SCN)
• Endoparasitic roundworm• Endoparasitic roundworm• Cysts can produce up to600 eggsgg
• Can complete lifecycle in28 days under optimal fieldconditions
• Reported in 82 of 92counties in Indiana*counties in Indiana*
• Yield loss
* Faghihi, J., and V.R. Ferris. 2006. http://www.entm.purdue.edu/Entomology/ext/targets/e-series/EseriesPDF/E-210.pdf.
Winter Annual Weeds
Winter Annual Weed Hosts
Purple deadnettle Henbit Field pennycress
Shepherd’s-purse Common chickweed
Smallflowered bittercress
Cool Season Perennial Host
Mouseear chickweed
SCN and Winter Annual Weeds• Winter annual weed survey-20041
- Indiana fields with SCN were sampled- Found 93% of fields had winter annual weedFound 93% of fields had winter annual weedhosts
• Field experiment: SCN can complete its lifecycle onpurple deadnettle 2purple deadnettle.
• Growth chamber experiment: Juveniles survivedperiods of cold temperature in roots and continued development when temperatures warmed 3development when temperatures warmed.3
1Creech, J.E., and W.G. Johnson. 2006. Weed Tech. 20:1066-1075.2Creech, J.E., W.G. Johnson, J.Faghihi, V.R. Ferris, and A. Westphal. 2005. Crop Management.3Creech, J.E., J.B. Santini, S.P. Conely, A. Westphal, and W.G. Johnson. 2007. Weed Science. 55:592-598.
SCN Management
C i i h h• Crop rotation with non-hostcrop
• SCN-resistant soybean
• Weed management??
Objective
To determine if winter annual weedd iti d SCN l ti d itidensities and SCN population densities can be reduced by using winter covercrops or herbicidescrops or herbicides.
Materials & Method‘s• Experiment established in2003 (2006-2008)
West Lafayette
( )• 2 locations
- Northern site - W. LafayetteCh l ilt l l
yChalmers silty clay loamLow weed density and SCN
Vincennes
SCN- Southern site - Vincennes
Patton silt loam Vincennes
High weed density andSCN
Materials & Method‘s
• 2 crop rotations- Soybean - soybeany y- Soybean - corn
• 6 weed management tactics: - Untreated- Untreated- Spring + fall glyphosatetreatments (Weed free)S i l h t- Spring glyphosatetreatment
- Fall glyphosate treatmentg y- Wheat cover crop- Annual ryegrass covercrop (ARG)crop (ARG)
Data collection
SCN egg counts- Spring and fall 2007- Sieving and decanting*
Weed counts- Fall 2006-07
nematology.umd.edu/scn.html (McGawley)
Fall 2006 07- Spring 2007-08- Quadrats
* Faghihi, J., and J.M. Ferris. 2000. J. Nematol. 32:411-413.
Data analysis
PROC MIXED- Locations analyzed separately- Locations analyzed separately- All data were log transformed- Means separated at P=0.05p- Back-transformed means will bepresented for clarity
Northern SCN egg counts (no. / 100 cc of soil)Weed management * rotation * season
S (C)* S (S)
Weed management rotation seasonP=0.0145
Weed mgmt. Spring‘07
Fall‘07
Spring‘07
Fall‘07
/ 100 f il_________ no. / 100 cc of soil _________
UntreatedWheatWheatARGFall ‘06 (F)Fall 06 (F)F + S Spring ‘07 (S)p g ( )
* Spring 2007 corn planted
Northern SCN egg counts (no. / 100 cc of soil)Weed management * rotation * season
S (C)* S (S)
Weed management rotation seasonP=0.0145
Weed mgmt. Spring‘07
Fall‘07
Spring‘07
Fall‘07
/ 100 f il_________ no. / 100 cc of soil _________
Untreated 0 bWheat 6 abWheat 6 abARG 4 abFall ‘06 (F) 11 abFall 06 (F) 11 abF + S 4 abSpring ‘07 (S) 16 ap g ( )
* Spring 2007 corn planted
Northern SCN egg counts (no. / 100 cc of soil)Weed management * rotation * season
S (C)* S (S)
Weed management rotation seasonP=0.0145
Weed mgmt. Spring‘07
Fall‘07
Spring‘07
Fall‘07
/ 100 f il_________ no. / 100 cc of soil _________
Untreated 0 b 10 aWheat 6 ab 0 aWheat 6 ab 0 aARG 4 ab 4 aFall ‘06 (F) 11 ab 1 aFall 06 (F) 11 ab 1 aF + S 4 ab 5 aSpring ‘07 (S) 16 a 0 ap g ( )
* Spring 2007 corn planted
Northern SCN egg counts (no. / 100 cc of soil)Weed management * rotation * season
S (C)* S (S)
Weed management rotation seasonP=0.0145
Weed mgmt. Spring‘07
Fall‘07
Spring‘07
Fall‘07
/ 100 f il_________ no. / 100 cc of soil _________
Untreated 0 b 10 a 1 aWheat 6 ab 0 a 2 aWheat 6 ab 0 a 2 aARG 4 ab 4 a 4 aFall ‘06 (F) 11 ab 1 a 2 aFall 06 (F) 11 ab 1 a 2 aF + S 4 ab 5 a 2 aSpring ‘07 (S) 16 a 0 a 0 ap g ( )
* Spring 2007 corn planted
Northern SCN egg counts (no. / 100 cc of soil)Weed management * rotation * season
S (C)* S (S)
Weed management rotation seasonP=0.0145
Weed mgmt. Spring‘07
Fall‘07
Spring‘07
Fall‘07
/ 100 f il_________ no. / 100 cc of soil _________
Untreated 0 b 10 a 1 a 6 bWheat 6 ab 0 a 2 a 47 abWheat 6 ab 0 a 2 a 47 abARG 4 ab 4 a 4 a 30 abFall ‘06 (F) 11 ab 1 a 2 a 161 aFall 06 (F) 11 ab 1 a 2 a 161 aF + S 4 ab 5 a 2 a 39 abSpring ‘07 (S) 16 a 0 a 0 a 46 abp g ( )
* Spring 2007 corn planted
SCN Conclusions• S(C) rotation in spring
- Higher SCN egg counts in spring timingthan untreated
- SCN eggs may have hatched in untreatedl tplots
• S(S) rotation in the fall• S(S) rotation in the fall- Higher SCN in fall timing than untreated- Winter annual weeds may serve as trap cropy p p
• Cover crops not effective in reducing SCNpopulations
Spring weed counts (Northern)
50
60
40
50
r m
2
30
ds
pe
10
20
Weed
0
10
Unt. ARG Wheat Fall gly.
Spring weed counts (Northern)
50
60a
40
50
r m
2
b b30
ds
pe b b
10
20
Weed
0
10c
Unt. ARG Wheat Fall gly.
Spring weed counts (Northern)
50
60
40
50
r m
2
30
ds
pe
a a
10
20
Weed a a a
0
10b
Unt. ARG Wheat Fall gly.
Spring weed counts (Northern)
50
60
40
50
r m
2
a30
ds
pe
aa
a
aa a
10
20
Weed a
b0
10b
Unt. ARG Wheat Fall gly.
Spring weed counts (Northern)
50
60
40
50
r m
2
30
ds
pe
a aa
a
a
10
20
Weed a a a
a
0
10b b
ba
bc
Unt. ARG Wheat Fall gly.
Spring weed counts (Southern)
240
160
200
r m
2
120
160
ds
pe
40
80
Weed
0
40
Unt. ARG Wheat Fall gly.
Spring weed counts (Southern)
240a
a a
160
200
r m
2
120
160
ds
pe
40
80
Weed
0
40 b
Unt. ARG Wheat Fall gly.
Spring weed counts (Southern)
240
160
200
r m
2
120
160
ds
pe
40
80
Weed
ba a
0
40c
Unt. ARG Wheat Fall gly.
Spring weed counts (Southern)
240
160
200
r m
2
120
160
ds
pe
aab
40
80
Weed
ba a
bab
0
40c c
Unt. ARG Wheat Fall gly.
Spring weed counts (Southern)
240
160
200
r m
2
a
120
160
ds
pe
aab
a
a
40
80
Weed
ba a
bab
b
0
40c c c
Unt. ARG Wheat Fall gly.
Spring Weed Count Conclusions
• Fall glyphosate treatments provide betterweed suppression than cover crops.
• Annual ryegrass and wheat did not reduceSCN winter weed hostsSCN winter weed hosts.
• Winter weed hosts seem to compete betterthan the non-hosts with annual ryegrassthan the non hosts with annual ryegrassand wheat.
Future Research
T d t i if i t l d• To determine if winter annual weeds can:- Stimulate earlier egg hatch in spring- Serve as trap crops in the field- Serve as trap crops in the field- Increase soil microbes that suppressSCN
Questions??