ISU FARM Research Report - Iowa State University · ISRF12-99 February 2013 2012 ISU FARM Research...

ISRF12-99 February 2013

2012

ISU FARM Research Report

1-2012 ISU FARM Cover.indd 1 2/20/13 8:46 PM

ISU FARM b Farmer-Assisted Research and Management b 2012 1

Table of ContentsIntroduction........................................................................................................................................................................................2

Interpreting.P-Values.in.ISU.FARM.Trials..........................................................................................................................................4

Corn Production

. Planting.Trials.................................................................................................................................................................................5

. Drought-Tolerant.Hybrid.Trials......................................................................................................................................................8

. Tillage..............................................................................................................................................................................................9

. Fertilizer.and.Growth.Regulators.................................................................................................................................................12

. Sulfur.............................................................................................................................................................................................13

. Micronutrients..............................................................................................................................................................................15

. Cover.Crop...................................................................................................................................................................................17

Corn Protection. Corn.Rootworm............................................................................................................................................................................19

. Seed.Treatments............................................................................................................................................................................21

. Fungicide......................................................................................................................................................................................24

. Goss’s.Wilt.....................................................................................................................................................................................27

Soybean Production. Planting.Trials...............................................................................................................................................................................29. Land.Rolling..................................................................................................................................................................................32

. Sulfur.............................................................................................................................................................................................33

. Micronutrients.and.Foliar.Feeding..............................................................................................................................................34

Soybean Protection

. Seed.Treatments............................................................................................................................................................................36

. Fungicide.and.White.Mold.Trials.................................................................................................................................................38

2012.Research.Farm.and.Cooperator.Locations.(map)...................................................................................................................41

Acknowledgments

. Cooperators..................................................................................................................................................................................41

. Research.Partners..........................................................................................................................................................................42

. Research.Sponsors........................................................................................................................................................................43

2 ISU FARM b Farmer-Assisted Research and Management b 2012

ISU FARM Specialists

Micah Smidt310.S..Main.Street

Kanawha,.IA.50447

Phone/Fax:.(641).762-3247

Cell:.(641).860-0901

[email protected]

Lyle Rossiter2030.640th.Street

Newell,.IA.50568

Phone/Fax:.(712).272-3512

[email protected]

Josh Sievers6320.500th.Street

Sutherland,.IA.51508

Phone:.(712).446-2626

Cell:.(712).539-2510

Fax:.(712).446-3825

[email protected]

Wayne Roush36515.Highway.E34

Castana,.IA.51010

Phone/Fax:.(712).885-2802

[email protected]

IntroductionIowa.State.University.(ISU).has.a.long-standing.relationship.with.Iowa.corn.and.soybean.farmers..As.a.part.of.this.relation-ship,.ISU.works.to.provide.quality,.unbiased.research.data.to.assist.in.the.decision-making.process.on.farm.operations...In.2006,.Iowa.State.began.to.expand.that.commitment,.with.the.assistance.of.northwest.Iowa.farmers,.by.conducting.research.on.their.farms..In.2011,.ISU.Farmer-Assisted.Research.and.Management.(FARM).was.established.to.expand.the.northwest.Iowa.program.to.the.rest.of.the.state.through.Iowa.State.University.Extension.and.Outreach.field.agronomists.and.ag..specialists..In.2012,.more.than.50.farmer-cooperators.assisted.in.conducting.over.130.research.trials.that.are.shared.in.this.publication...As.Iowa.State.University.continues.to.expand.locations.for.ISU.FARM,.the.need.for.farmers.to.participate.will.increase.as.well..If.you.are.interested.in.participating.in.this.program,.please.contact.one.of.the.ISU.Extension.and.Outreach.ag.specialists.or..field.agronomists.listed.

Zack Koopman1308.U.Avenue

Boone,.IA.50036

Phone:.(515).296-4083

Cell:.(515).291-2089

[email protected]

Lance Miller3114.Louisa-Washington.Road

Crawfordsville,.IA.52621

Phone/Fax:.(319).658-2353

Cell:.(319).750-4892

[email protected]

Jim Rogers53020.Hitchcock.Avenue

Lewis,.IA.51544

Phone:.(712).769-2402

Cell:.(712).789-0464

[email protected]


Field AgronomistsFor.more.in-depth.information.on.the.topics.discussed.and.other.topics.related.to.corn.and.soybean.management.in.Iowa,.contact.the.extension.field.agronomists.in.your.area.

Terry Basol3327.290th.Street

Nashua,.IA.50658

Phone:.(641).435-4864

Cell:.(641).426-6801

Fax:.(641).435-2009

[email protected]

Mark Carlton219.B.Avenue.West

Albia,.IA.52531

Phone:.(641).932-5612

Cell:.(641).777-7883

Fax:.(641).932-5662

[email protected]

Joel DeJong251.12th.Street.SE

LeMars,.IA.51031

Phone:.(712).546-7835

Cell:.(712).540-1085

Fax:.(712).546-7837

[email protected]

Jim Fawcett4265.Oakcrest.Hill.Road.SE

Iowa.City,.IA.52246

Phone:.(319).337-.2145

Cell:.(319).721-6554

Fax:.(319).337-7864

[email protected]

John Holmes210.First.Street.SW,.Box.433

Clarion,.IA.50525

Phone:.(515).532-3453

Cell:.(515).571-4010

Fax:.(515).532-3415

[email protected]

Paul Kassel110.W..4th.Street

Spencer,.IA.51301

Phone:.(712).262-2264

Cell:.(712).260-3389

Fax:.(712).262-8481

[email protected]

Brian Lang325.Washington.Street,..

Suite.B

Decorah,.IA.52101

Phone:.(563).382-2949

Cell:.(563).387-7058

Fax:.(563).382-2940

[email protected]

Mark Licht202.H.Avenue,.P.O..Box.118

Nevada,.IA.50201

Phone:.(515).382-6551

Cell:.(712).790-7233

Fax:.(515).382-2696

[email protected]

Clarke McGrath906.6th.Street

Harlan,.IA.51537

Phone:.(712).733-2741

Cell:.(712).215-2146

Fax:.(712).755-7112

[email protected]

Aaron Saeugling53020.Hitchcock.Avenue

Lewis,.IA.51544

Phone:.(712).769-2600

Cell:.(712).254-0227

Fax:.(712).769-2610

[email protected]

Virgil Schmitt1514.Isett.Avenue

Muscatine,.IA.52761

Phone:.(563).263-5701

Cell:.(563).260-3721

Fax:.(563).263-5707

[email protected]

This.publication.was.prepared.by.Nathan.Bestor.with.contributions.from.Josh.Sievers,.Wayne.Roush,.Lyle.Rossiter,.Micah.Smidt,.Zack.Koopman,.

Aaron.Saeugling,.Joel.DeJong,.Paul.Kassel,.Adam.Sisson,.Erin.Hodgson,.Mark.Honeyman,.Antonio.Mallarino,.John.Sawyer,.and.Greg.Tylka..

.

NOTE:.This.is.a.progress.report.and,.therefore,.is.not.necessarily.conclusive..Further.data.may.result.in.conclusions.somewhat.different.from.those.

reported.here..Information.in.this.publication.may.be.specific.to.Iowa..

.©.2013.Iowa.State.University.of.Science.and.Technology..All.rights.reserved..

.

The.information.in.this.report.is.not.to.be.used.for.publication.without.the.express.written.consent.of.ISU.FARM,.Curtiss.Hall,.Iowa.State.Univer-

sity,.Ames,.IA..Information.contained.within.does.not.constitute.a.recommendation.or.endorsement.of.product.use.

.

.

. . . and justice for all

The.U.S..Department.of.Agriculture.(USDA).prohibits.discrimination.in.all.its.programs.and.activities.on.the.basis.of.race,.color,.national.origin,.age,.

disability,.and.where.applicable,.sex,.marital.status,.familial.status,.parental.status,.religion,.sexual.orientation,.genetic.information,.political.beliefs,.

reprisal,.or.because.all.or.part.of.an.individual’s.income.is.derived.from.any.public.assistance.program..(Not.all.prohibited.bases.apply.to.all.programs.).

Persons.with.disabilities.who.require.alternative.means.for.communication.of.program.information.(Braille,.large.print,.audiotape,.etc.).should.contact.

USDA’s.TARGET.Center.at.202-720-2600.(voice.and.TDD)..To.file.a.complaint.of.discrimination,.write.to.USDA,.Director,.Office.of.Civil.Rights,..

1400.Independence.Avenue.SW,.Washington,.DC.20250-9410,.or.call.800-795-3272.(voice).or.202-720-6382.(TDD)..USDA.is.an.equal.opportunity.

provider.and.employer.

Issued.in.furtherance.of.Cooperative.Extension.work,.Acts.of.May.8.and.June.30,.1914,.in.cooperation.with.the.U.S..Department.of.Agriculture..

Cathann.A..Kress,.director,.Cooperative.Extension.Service,.Iowa.State.University.of.Science.and.Technology,.Ames,.Iowa.


Interpreting P-Values in ISU FARM TrialsStatistics Shed Light on Yield VariationWhen.comparing.yields.from.a.field,.even.when.the.plots.measured.are.next.to.each.other,.the.measured.yields.very.well.may.differ..Yield.differences.can.be.attributed.to.several.factors.such.as:.variation.within.the.soil.map.unit,.soil.fertility,.moisture.availability,.insect.infestation,.disease.pressure,.or.differences.in.planting.or.harvesting.techniques.

When.at.least.three.replications.of.a.trial.are.conducted,.statistics.can.be.used.to.determine.if.variations.are.attributed.to.the.treatment.or.to.factors.unrelated.to.the.treatments.being.compared..All.trials.reported.were.replicated.at.least.three.times.at.the.site.in.the.farmer-cooperator’s.field.

P-ValuesP-values.are.used.to.help.determine.if.differences.in.a.measurement.(yield.in.this.case).can.be.attributed.to.treatments.and.not.other.factors..The.lower.the.p-value,.the.more.likely.it.is.that.the.treatments.are.actually.affecting.yield..Common.benchmarks.for.p-values.in.field.research.are.0.10.and.0.05..If.an.experiment.has.a.p-value.of.0.10,.we.would.be.90.percent.confident.that.the.differences.observed.are.in.response.to.the.treatments..Likewise,.if.an.experiment.has.a.p-value.of.0.05,.we.can.say.we.are.95.percent.confident.that.the.differences.observed.were.in.response.to.the.treatments..Keep.in.mind.that.the.larger.a.p-value,.the.lower.the.probability.that.the.treatment.effect.was.responsible.for.differences.observed.

A Finding of “No Statistical Difference” Is Still Valuable DataEven.if.yields.are.not.statistically.different,.it.is.important.to.remember.that.the.data.are.still.valuable.because.they.tell.us.that.the.treatments.did.not.produce.a.difference.in.yield.(or.other.factors.measured)..Simply.knowing.this.can.help.a.grower.learn.more.about.the.conditions.and.performance.of.a.given.field,.as.well.as.aid.future.management.decisions.


ProductionCorn | Planting TrialsIn.2012,.ISU.FARM.had.various.experiments.examining.corn.planting.populations.and.planter.closing.wheel.configurations.and.their.relation.to.yield..Yield.results.at.the.end.of.the.season.may.be.impacted.by.early.season.planting.decisions..For.this.reason,.it.is.important.to.have.information.on.the.best.early.season.practices.to.aid.decision.making.before.the.season.begins.

Planting PopulationFarmers.continue.to.increase.corn.planting.populations.in.hopes.of.increasing.yields..But.as.seed.prices.rise,.it.is.important.for.farmers.to.find.a.population.that.maximizes.both.yield.and.profit..The.following.trials.evaluated.the.effect.of.differing.planting.populations.on.grain.yield..

Three.planting.population.trials.with.five.treatments.each.were.conducted.in.2012.in.Boone.and.Story.counties.(Table.1)...Treatments.consisted.of.plots.with.25,000,.30,000,.35,000,.40,000,.and.45,000.seeds/acre..Spring.and.fall.stand.count.data.were.collected.to.assess.planting.populations..Yield.results.varied.by.location..In.trial.1,.the.highest.yielding.planting.rate.was.35,000.seeds/acre.and.the.lowest.was.45,000.seeds/acre.(Table.2)..In.trial.2,.there.was.no.difference.found.between.treatments.of.30,000,.35,000,.40,000,.and.45,000.seeds/acre..But.the.yield.at.25,000.seeds/acre.was.significantly.lower.than.all.the.other.treatments.in.trial.2.(Table.2)..And.finally,.in.trial.3,.plots.at.40,000.and.45,000.seeds/acre.were.significantly.lower.yielding.than.the.remaining.treatments.

Though.the.results.vary.from.trial.to.trial,.there.are.some.takeaway.points..In.all.of.the.trials,.35,000.seeds/acre.was.in.the..top.yielding.tier.of.treatments.and.was.not.significantly.lower.yielding.than.any.other.treatment..According.to.ISU.Extension.Corn.Specialist.Roger.Elmore’s.research,.the.optimal.planting.rate.for.yield.falls.in.the.range.of.34,500.to.37,000.seeds/acre.and.the.optimal.planting.rate.for.profit.falls.between.30,000.and.35,000.seeds/acre..Thus,.the.results.of.the.research.presented..seem.to.follow.Roger.Elmore’s.recommendations.on.planting.population.

Table 1. Hybrid, row spacing, planting date, previous crop, and tillage practices from three planting population trials in Boone and Story counties, 2012.

Row Spacing Trial County Hybrid (inch) Planting Date Previous Crop Tillage

1 Boone Pioneer 1151YHR 30 5/9/2012 Corn Conventional2 Boone Pioneer PO528XR 30 5/11/2012 Corn Conventional3 Story Channel 209-85 VT3 Pro 30 5/14/2012 Corn Conventional


Table 2. Spring stand, fall stand, and yield data from three planting population trials in Boone and Story counties in 2012.

Spring Stand Fall Stand Yield* Trial Treatments (plants/meter) (plants/meter) (bushels/acre) P-value

1 25,000 23,600 E 23,800 E 198.0 A 0.19 30,000 28,100 D 28,300 D 201.5 A 35,000 33,200 C 33,000 C 204.4 A 40,000 37,700 B 37,600 B 195.7 A 45,000 42,100 A 41,900 A 191.6 A2 25,000 22,500 E 22,600 E 180.6 B 0.008 30,000 28,300 D 28,300 D 190.9 A 35,000 32,900 C 32,300 C 195.3 A 40,000 36,900 B 35,800 B 189.8 A 45,000 41,500 A 40,300 A 193.7 A3 25,000 22,500 E 22,600 E 183.4 A 0.0007 30,000 28,300 D 28,300 D 184.7 A 35,000 32,900 C 32,300 C 180.7 A 40,000 36,900 B 35,800 B 169.8 B 45,000 41,500 A 40,300 A 161.4 B

*Values denoted with the same letter are not significantly different at the significance level 0.05.

A.second.round.of.corn.planting.population.trials.was.conducted.in.Sac.and.Cherokee.counties..Trial.1.compared.36,400.and.41,600.seeds/acre.and.trial.2.compared.33,100.and.37,600.seeds/acre.(Table.3)..Statistically.speaking,.neither.trial.showed.significant.yield.differences.between.treatments.(Table.4).

Table 3. Hybrid, row spacing, planting date, previous crop, and tillage practices from two planting population trials in Sac and Cherokee counties in 2012.

Row Spacing Trial County Hybrid (inch) Planting Date Previous Crop Tillage

1 Sac AgriGold A6481 STXRIB 20 4/25/2012 Soybean Fall disk2 Cherokee DK5509 SmartStax 30 5/10/2012 Soybean Spring soil finisher

Table 4. Spring stand, fall stand, and yield data from two planting population trials in Sac and Cherokee counties in 2012.

Spring Stand Fall Stand Yield* Trial Treatments (plants/meter/acre) (plants/meter/acre) (bushels/acre) P-value

1 36,400 — 33,083 B 152.8 A 0.84 41,600 — 38,333 A 153.8 A 2 33,100 31,750 B 29,583 B 201.4 A 0.40 37,600 36,833 A 34,750 A 210.3 A



Closing Wheel ConfigurationsA.planting.study.on.corn.examined.closing.wheel.type.and.wheel.pressure.on.yield..Treatments.consisted.of.conventional.press.wheel,.finger.press.wheel,.and.half.conventional.and.half.finger.press.wheel,.each.with.both.heavy.downward.pres-sure.and.light.downward.pressure..Because.of.the.study.design,.we.can.look.for.yield.differences.between.closing.wheel.type,.amount.of.pressure,.and.closing.wheel.type.*wheel.pressure..It.should.also.be.noted.that.these.trials.were.nearly.identical.in.design,.but.trial.1.was.no-till.and.trial.2.was.conventionally.tilled.(Table.5).

In.both.trials,.the.only.differences.in.yield.were.from.closing.wheel.type..In.trial.1,.the.conventional.press.wheel.treatment.had.significantly.greater.yield.than.the.finger.press.wheel,.but.not.the.half.and.half.press.wheel..There.was.no.difference.between.the.finger.press.wheel.and.the.half.and.half.press.wheels..In.trial.2,.the.half.and.half.press.wheel.treatment.had.significantly.greater.yield.than.both.the.conventional.and.the.finger.press.wheel..Differences.in.wheel.pressure.and.closing.wheel.type..*wheel.pressure.were.not.detected.in.either.trial.1.or.trial.2.(Table.6).

Table 5. Hybrid, row spacing, planting date, planting population, previous crop, and tillage practices from two closing wheel and wheel pressure trials in Boone County in 2012.

Row Spacing Planting Population Trial County Hybrid (inch) Planting Date (seeds/acre) Previous Crop Tillage

1 Boone Fontonelle 5T128 30 5/15/2012 35,000 Soybean No-till2 Boone Fontonelle 5T128 30 5/15/2012 35,000 Soybean Conventional

Table 6. Data from two closing wheel and wheel pressure planting trials in Boone County in 2012.*

Yield Yield Yield Trial Wheel (bushels/acre) P-value Pressure (bushels/acre) P-value Wheel*Pressure (bushels/acre) P-value

1 Conventional 201.6 A 0.05 High 195.1 A 0.08 Conventional*High 200.2 A 0.68 Conventional*Low 203.0 A Finger Press 192.2 B Low 200.6 A Finger*High 197.4 A Finger*Low 196.8 A Half and Half 199.7 AB Half and Half*High 197.4 A Half and Half*Low 202.0 A2 Conventional 188.4 B 0.01 High 193.8 A 0.44 Conventional*High 189.7 A 0.22 Conventional*Low 187.1 A Finger Press 190.3 B Low 191.6 A Finger*High 188.2 A Finger*Low 192.4 A Half and Half 199.3 A Half and Half*High 203.4 A Half and Half*Low 195.2 A



Corn | Drought-Tolerant Hybrid TrialsTesting.for.drought.tolerance.was.very.appropriate.in.2012..AQUAmax™.and.Artesian™,.drought-resistant.hybrids.from.DuPont.Pioneer.and.Agrisure,.respectively,.were.tested.against.equivalent.hybrids.without.drought.tolerance..All.trials.were.conducted.in.Sioux.County.in.partnership.with.Dordt.College. Two.trials.(1–2).compared.AQUAmax™.hybrids.with.a.similar.conventional.hybrid,.and.trial.1.had.fungicide.(Quilt.Xcel®).applied.to.all.treatments.(Table.1)..Four.trials.(3–6).compared.Artesian™.hybrids.and.a.similar.conventional.hybrid,.and..trials.4.and.5.had.fungicide.(Quilt.Xcel®).applied.to.all.treatments.

AQUAmax™..In.both.trials,.AQUAmax™.hybrids.returned.significantly.greater.yields.than.conventional.hybrids..In.trial.1,.AQUAmax™.hybrids.led.to.a.12.7.bushel.increase.and.an.8.2.bushel.increase.in.trial.2.(Table.2)..These.results.are.consistent.with.what.would.be.expected.of.a.drought-tolerant.hybrid.during.a.drought.year.and.suggest.that.the.use.of.drought-tolerant.hybrids.in.areas.prone.to.dry.weather.may.be.advantageous.over.conventional.hybrid.use.

Artesian™. There.was.no.yield.benefit.to.using.Artesian™.drought-resistant.hybrids.in.2012,.despite.severe.drought.in.the.area..It.is.unknown.as.to.why.there.was.not.a.yield.difference.in.this.trial.

Table 1. Hybrid used, row spacing, planting date, planting population, previous crop, and tillage practices in the drought- resistant hybrid trials in 2012.


1 Sioux Treatment 30 4/26/2012 32,900 Soybean Spring disk2 Sioux Treatment 30 4/26/2012 32,900 Soybean Spring disk3 Sioux Treatment 30 4/25/2012 32,900 Soybean Spring disk4 Sioux Treatment 30 4/25/2012 32,900 Soybean Spring disk5 Sioux Treatment 30 4/25/2012 32,900 Soybean Spring disk6 Sioux Treatment 30 4/25/2012 32,500 Soybean Conventional disk

Table 2. Yield results from drought-resistant hybrid trials in 2012.

Yield Trial Treatments (bushels/acre) P-value

1 35F50 AMR (conventional) 181.9 0.04 PO636 HR (AQUAmax™) 194.62 35F50 AMR (conventional) 188.0 0.004 PO636 HR (AQUAmax™) 196.23 NK49J-3000GT (conventional) 165.2 0.09 N459P-4011 (Artesian™) 160.94 NK49J-3000GT (conventional) 161.7 0.19 N459P-4011 (Artesian™) 149.1 5 NK49J-3000GT (conventional) 195.3 0.3 N459P-4011 (Artesian™) 191.46 NK49J-3000GT (conventional) 179.3 0.12 N459P-4011 (Artesian™) 170.6


Corn | TillageIn.2012,.ISU.FARM.conducted.three.residual.no-till.soybean-corn.production.(RNTS-CP).trials..These.trials.measured.residual.yield.effects.on.conventional.corn.production.when.soybeans.were.planted.into.tilled.or.non-tilled.cornstalks.the.previous.year..A.range.of.different.tillage.comparisons.also.were.conducted.in.three.other.trials.in.2012..Finally,.two.trials.examined.various.residue.decomposition.management.programs.and.their.effect.on.yield.in.no-till.fields..

Residual No-till Soybean-Corn ProductionTwo.RNTS-CP.trials.were.located.in.Lyon.County.and.one.in.Sioux.County.(Table.1)..Treatments.were.applied.in.2011;.half.of.the.plots.consisted.of.soybean.planted.into.tilled.corn.residue,.and.half.were.soybean.planted.into.no-till.corn.residue..Corn.was.then.planted.in.2012..After.analysis,.results.indicate.there.were.no.yield.differences.detected.in.any.of.the.trials.(Table.2)..Long-term.research.on.the.topic.may.be.necessary.in.order.to.make.appropriate.recommendations.

Table 1. Hybrid, row spacing, planting date, planting population, and previous crop in three RNTS-CP tillage trials in 2012.

Row Spacing Planting Population Trial County Hybrid (inch) Planting Date (seeds/acre) Previous Crop

1 Lyon GH 7647 3000 GT 30 5/1/2012 32,000 Soybean2 Lyon DKC 5509 30 5/12/2012 31,000 Soybean3 Sioux Pioneer 0448 AM1 30 4/25/2012 32,900 Soybean

Table 2. Yield data from tillage trials in 2012 RNTS-CP.

No-till Yield Till Yield Trial Treatment (bushels/acre) (bushels/acre) P-value

1 No-till 108.5 110.3 0.362 No-till 187.6 205.7 0.413 No-till 167.1 166.5 0.84


TillageThree.trials.examining.tillage.practices.in.corn.were.conducted.in.three.Iowa.counties.in.2012.(Table.3)..These.trials.investi-gated.a.broad.range.of.questions.concerning.tillage.and.included.comparisons.of.soil.finishing,.strip.tillage,.and.strip.tillage..+.fertilizer;.spring.disk.tillage.and.no-till;.and.disk/chisel,.strip,.and.no-till.(Table.4)..In.trial.1,.there.were.no.significant.yield..differences.between.any.of.the.tillage.types..In.trial.2,.plots.with.no-till.out-yielded.spring.disk.tillage..However,.this.was.largely.due.to.drought.conditions.in.one.of.the.plots..In.trial.3,.both.the.disk/chisel.and.strip-tillage.plots.yielded.significantly.greater.(approximately.20.bu/acre).than.the.no-till.control.plots..These.trials.represent.only.one.year.of.data.and.long.term.till-age.practices.may.show.differing.results.

Table 3. Hybrid, row spacing, planting date, planting population, and previous crop in three corn tillage trials in Lyon, Sioux, and Story counties in 2012.

Row Spacing Planting PopulationTrial County Hybrid (inch) Planting Date (seeds/acre) Previous Crop

1 Lyon DeKalb 4994 30 5/7/2012 VR 32–35,000 Soybean2 Sioux GH E104T6 30 4/26/2012 34,000 Soybean3 Story Pioneer 1162AM 30 5/14/2012 35,000 Corn

Table 4. Yield data from corn tillage trials in 2012.

Yield* Trial Treatment (bushels/acre) P-value

1 Soil finishing 212.3 A 0.20 Strip till 208.4 A Strip till + fertilizer 214.0 A2 Till (spring disk) 70.2 B 0.006 No-till 111.2 A3 Disk/chisel 173.3 A 0.050 Strip 172.7 A No-till 154.6 B



Residue DecompositionManaging.crop.residue.is.a.concern.for.many.farmers.who.are.growing.corn.on.corn..In.2012,.two.trials.examining.corn.on.corn.residue.decomposition.were.conducted..Treatments.consisted.of.an.untreated.control,.15.lb.of.nitrogen,.30.lb.of.nitrogen,..Accomplish®.LM.with.and.without.15.lb.and.30.lb.of.nitrogen.per.acre..In.this.study,.there.were.no.statistical.differences.detected.between.treatments..In.trial.1,.despite.the.25.bushel.per.acre.difference.among.treatment.averages,.there.was.no..statistical.difference.because.of.the.high.amount.of.variation.found.within.the.field.where.the.trial.was.conducted..This..variation.makes.it.impossible.to.attribute.the.yield.difference.to.the.specific.treatment.applied..There.was.no.treatment.effect..in.trial.2.

Table 5. Hybrid, row spacing, planting date, planting population, and previous crop in residue decomposition trials in 2012.


1 Story Pioneer 1162AM 30 5/14/2012 35,000 Corn No-till 2 Pottawattamie Pioneer 1162 AM 30 4/24/2012 34,000 Corn No-till

Table 6. Yield data from the residue decomposition trial in 2012.

Yield* Trial Treatment (bushels/acre) P-value

1 Control 152.8 A 0.36 15 lb N 148.6 A 30 lb N 143.3 A Accomplish® LM 126.7 A Accomplish® LM + 15 lb N 119.0 A Accomplish® LM + 30 lb N 135.6 A2 Control 115.7 A 0.35 15 lb N 115.3 A 30 lb N 124.0 A Accomplish® LM 111.7 A Accomplish® LM + 15 lb N 122.8 A Accomplish® LM + 30 lb N 117.7 A



Corn | Fertilizer and Growth RegulatorsMethodsFertilizer trials..The.use.of.fertilizers.is.a.common.practice.of.farmers.in.Iowa..Fertilizers.are.important.to.maintain.yields,.especially.in.continuous.corn.cropping.systems..In.2012,.two.trials.in.Fremont.and.Story.counties.investigated.how.to..optimize.starter.fertilizer.(Table.1)..In.trial.1,.treatments.were.fertilizer.(10-34-0).applied.in.furrow,.2.x.2.placement,.in..furrow.and.2.x.2,.and.an.untreated.control..Fertilizer.was.applied.at.the.planting.date.in.strips..In.trial.2,.treatments.assessed.sidedress.application.of.nitrogen.(N)..Treatments.were.140.lb.N.pre-plant;.50.lb.N.pre-plant.and.90.lb.N.post-plant;.140.lb.N.post-plant;.and.90.lb.N.pre-plant.and.50.lb.N.post-plant.applications.(Table.2)..

Growth regulator trials. Two.growth.regulator.trials.were.conducted.in.Lyon.and.Sioux.counties..In.trial.1,.Ascend®.(5.oz/acre).was.applied.to.seed.in.furrow.as.a.growth.regulator..In.trial.2,.Generate®.(16.oz/acre).was.applied.on.May.21.(Table.3).

ResultsFertilizer trials..In.trial.1,.yield.was.not.affected.by.the.treatments.and.the.control.had.the.highest.yield..In.trial.2,.there.was.also.no.difference.between.treatments..Like.many.of.these.on-farm.trials,.long-term.system.approaches.cannot.be.summarized.as.one-year.trial..

Growth regulator trials..Neither.trial.had.significantly.increased.yields.in.the.plots.treated.with.growth.regulators.(Table.4).. Table 1. Hybrid used, row spacing, planting date, planting population, previous crop, and tillage practices in 2012 fertilizer trials.


1 Fremont P 33G66 30 4/26/2012 28,000 Flooded Conventional2 Story CropPlan 6325VT3Pro 30 5/5/2012 34,000 Corn Conventional

Table 2. Data from fertilizer trials in 2012.

Yield* Trial Treatment Pre-N* PPM N* (bushels/acre) P-value

1 10-34-0 in furrow — — 208.6 A 0.17 10-34-0 2 x 2 211.6 A 10-34-0 in furrow and 2 x 2 204.0 A Untreated control 211.7 A2 140 lb N pre-plant, 0 lb N post 23.0 A 2,745 B 212.2 A 0.64 50 lb N pre-plant, 90 lb N post 18.3 A 3,913 AB 205.9 A 0 lb N pre-plant, 140 lb N post 20.8 A 4,945 A 200.9 A 90 lb N pre-plant, 50 lb N post 20.5 A 5,563 A 200.8 A

*Values denoted with the same letter are not significantly different at the significance level 0.05. Table 3. Variety used, row spacing, planting date, planting population, and tillage practices of growth regulator trials 2012.


1 Lyon 37K11 30 4/26/12 VR 34–38,000 Soybeans Strip till 2 Sioux Pioneer 1151 YHR 30 4/24/12 32,900 Alfalfa Soil finisher

Table 4. Application and yield information for growth regulator trials in 2012.

Yield (bushels/acre)

Trial Treatment Rate (oz/acre) Application Date Treatment Control P-value

1 Ascend® 5 4/26/12 187.5 189.3 0.25 2 Generate® 16 5/21/12 195.5 201.8 0.38


Corn | SulfurSulfur.(S).fertilizer.applications.can.offer.yield.increases.where.S.deficiencies.are.present..The.objective.of.these.trials.was.to.evaluate.potential.for.S.deficiency.and.grain.yield.response.in.corn.to.S.applications..

MethodsIn.2012,.11.fields.with.no.manure.history.were.chosen.throughout.western.Iowa.to.participate.in.these.trials.as.first-year.fields..Calcium.sulfate.(gypsum).was.broadcast.on.strip.plots.as.the.S.source.with.the.exception.of.trial.11,.which.used..elemental.sulfur..The.S.rate.was.15.or.17.lb.S/acre.depending.on.the.location..In.three.additional.trials,.yields.were.measured.for.a.residual-S.effect..In.these.second-year.trials,.S.was.applied.at.a.rate.of.23.lb.S/acre.in.the.spring.of.2011.

Results

First-year TrialsThree.trials.(1,.8,.and.11).had.a.corn.grain.yield.increase.from.application.of.calcium.sulfate.S.fertilizer.(Table.2)..Trials.1..and.11.had.yield.increases.of.4.and.7.bu/acre,.respectively..Trial.8.had.the.largest.yield.response.from.the.application.of.S..at.32.bu/acre..The.remaining.trials.showed.no.evidence.that.the.application.of.S.had.a.positive.effect.on.yield..For.an..unexplained.reason,.and.something.not.expected,.trial.6.had.a.yield.reduction.from.S.application.

Second-year ResidualNone.of.the.residual-year.S.trials.had.a.yield.response.from.S.applied.to.the.2011.corn.crop..There.was.also.no.yield.improve-ment.in.2011.at.any.of.these.trials..

For.further.information.on.these.trials.and.other.research.on.sulfur.fertilization,.please.contact.John.Sawyer,.professor,.Depart-ment.of.Agronomy,.Iowa.State.University.Extension.and.Outreach.([email protected]).


Table 1. Site location and production practices for the corn sulfur trials in 2012.

Row Spacing Planting Population Previous Trial County Hybrid (inch) Planting Date (seeds/acre) Crop Tillage

Sulfur First Year 1 Mills Fontanelle 8V567 30 5/8/2012 33,000 Soybean No-till 2 Taylor Stine 9734VT3Pro 30 4/27/2012 30,600 Soybean No-till 3 Lyon GH 7647 3000 GT 30 5/1/2012 32,000 Soybean Spring disk 4 Osceola Pioneer 37K11 30 5/11/2012 Variable rate Soybean Fall strip till 36–38,000 5 Dickinson Channel Bio 199-5s 30 4/25/2012 36,000 Soybean Field cultivated 6 Lyon GH 8708 20 4/25/2012 31,500 Soybean Soil finisher 7 Lyon DKC 48-37 30 4/26/2012 32,316 Soybean No-till 8 Crawford Renze 7240RR2 30 4/24/2012 32,000 Soybean No-till 9 Monona LG 2642VT2RIB 30 4/25/2012 32,800 Soybean Conventional10 Monona LG 2549VT2RIB 30 4/23/2012 32,800 Soybean Conventional11 Clay Pioneer P0216HR 30 4/25/2012 35,600 Soybean Field finisher

Sulfur Second Year 12 Osceola DKC 4620 30 4/26/2012 35,000 Soybean Disk fall- field cultivated13 Lyon DKC 5509 30 5/12/2012 31,000 Soybean Spring disk14 Sioux DKC 5655 30 4/24/2012 32,900 Soybean Conventional disk

Table 2. Treatment application information and grain yield for corn sulfur trials in 2012.

Sulfur Rate Yield (bushels/acre) Trial Application Date (lb/acre) Sulfur Control P-value

Sulfur First Year 1 5/8/2012 17 218 217 0.87 2 4/27/2012 17 106 99 0.077 3 4/6/2012 15 160 157 0.212 4 4/5/2012 15 197 198 0.666 5 4/5/2012 15 214 213 0.681 6 4/10/2012 15 134 140 0.021 7 4/6/2012 15 79 88 0.285 8 4/17/2012 15 132 100 0.002 9 4/19/2012 15 195 190 0.28710 4/30/2012 15 228 232 0.26611 11/1/2011 15 235 231 0.038

Sulfur Second Year 12 5/11/2011 23 188 185 0.26613 5/11/2011 23 203 199 0.53114 5/11/2011 23 173 175 0.695


Corn | Micronutrients MethodsFour.side-by-side.micronutrient.trials.were.conducted.on.corn.in.2012.(Table.1)..The.treatments.were.a.mixture.of.boron,.zinc,.and.manganese.and.an.untreated.control..The.mixture.was.one.part.Winfield®.Max-in.ZMB.(1.qt/acre).and.one.part.Max-in.Boron.(0.5.pt/acre).applied.in.15.gallons.of.water/acre..Nutrient.samples.were.collected.from.soil.and.plant.tissue.to.monitor.micronutrient.changes.after.foliar.fertilizer.was.applied..All.samples.were.sent.to.Iowa.State.University.for.processing.by.Antonio.Mallarino..All.trials.were.replicated.three.times,.with.the.exception.of.trial.2.

ResultsSoil.and.plant.tissue.sample.results.can.be.found.in.Table.2..Phosphorous.and.potassium.also.were.sampled.and.found.to.be.within.an.optimal.range.for.corn..

None.of.the.yields.in.the.micronutrient-treated.plots.was.found.to.be.significantly.greater.than.the.control.plots..In.trial.2,.control.plots.had.significantly.greater.yields.than.plots.treated.with.micronutrients.

For.further.information.on.these.trials.and.other.information.regarding.micronutrient.research,.please.contact.Antonio..Mallarino,.professor,.Iowa.State.University.Extension.and.Outreach.([email protected]).

Table 1. Hybrid, row spacing, planting date, previous crop, and tillage practices from three planting population trials in Osceola and Lyon counties in 2012.


1 Osceola DKC 4812 30 4/26/2012 35,000 Soybean Fall disk- spring field cultivated2 Osceola Pioneer 9910 30 4/26/2012 Variable rate Soybean Fall strip tilled 32–36,0003 Lyon DKC 5204 30 4/27/2012 34,500 Corn Fall rip-spring soil finish4 Lyon Producers 5684 30 4/25/2012 Variable rate Soybean Field cultivated

Table 2. Nutrient levels of the soil in the micronutrient trials in 2012.

Soil Plant

Boron Zinc Manganese Organic Matter Boron Zinc Manganese Trial (ppm) (ppm) (ppm) (%) (ppm) (ppm) (ppm)

1 0.73 0.81 25.8 5.8 9 26 542 0.77 0.79 14.2 5.8 8 33 583 0.87 5.67 25.1 5.4 8 34 544 0.52 2.97 24.6 5.0 9 37 63

Table 3. Yield and application date of micronutrient trials in 2012.

Micro Mix Yield Control Yield Trial Treatments Application Date (bushels/acre) (bushels/acre) P-value

1 Micro Mix 6/7/2012 171.1 172.1 0.552 Micro Mix 5/13/2012 183.0 193.7 0.0043 Micro Mix 6/8/2012 133.8 141.0 0.084 Micro Mix 6/5/2012 211.3 206.9 0.70


Another.micronutrient.trial.was.conducted.in.2012.using.foliar-applied.micronutrients.and.glyphosate.as.treatments...Individual.treatments.were.glyphosate,.manganese,.zinc,.glyphosate.+.manganese,.glyphosate.+.zinc,.and.glyphosate.+..manganese.+.zinc..Treatments.were.applied.on.July.13,.2012..Tissue.samples.were.measured.for.nutrient.levels.pre-..(July.11,.2012).and.post-application.(July.30,.2012).of.micronutrients.and.glyphosate..

There.were.no.treatment.differences.among.zinc.and.manganese.levels.in.the.post-application.sampling..There.were.also.no.yield.differences.among.treatments..

Table 4. Information of micronutrient trial in 2012.


1 Story FC 29R219 30 5/17/2012 140,000 Corn Conventional

Table 5. Yield of micronutrient and glyphosate study in 2012.

Yield Trial Treatments Zinc Pre Manganese Pre Zinc Post Manganese Post (bushels/acre)

1 Control 38.0 75.3 44.3 58.2 63.2 Glyphosate 38.0 70.7 42.8 60.8 64.0 Manganese 39.2 73.3 48.5 60.8 62.2 Zinc 38.0 79.0 42.8 63.3 61.2 Glyphosate + manganese 40.5 71.7 43.3 55.7 63.0 Glyphosate + zinc 36.0 72.5 46.8 62.2 58.8 Glyphosate + manganese + zinc 38.0 74.8 44.5 65.7 59.6

P-value 0.57 0.90 0.59 0.53 0.48

No differences were detected between treatments for all data collected.


Corn | Cover CropCover.crops.can.benefit.farmers.by.aiding.in.erosion.control,.increasing.organic.matter.in.the.soil,.and.even.improving.nitro-gen.fixation,.among.other.things..These.benefits.are.dependent.on.which.cover.crop.is.grown..Choosing.the.proper.cover.crop.depends.on.the.time.of.year.it.is.to.be.planted.and.desired.function..These.fields.were.chosen.due.to.prolonged.flooding.that.occurred.in.2011..The.farmer.wanted.to.test.whether.or.not.the.use.of.a.rye.cover.would.increase.biological.activity.in.the.soil.after.the.floods..

Cover vs. No CoverCover.crop.use.was.examined.in.two.trials.in.Harrison.County.(Table.1)..Oats.were.applied.at.1.5.bushels.per.acre.on..April.1,.2012,.and.were.mixed.with.fertilizer.before.application..Afterwards,.the.field.was.tilled.to.incorporate.the.oats.into..the.soil..When.the.oats.were.approximately.12.inches.tall,.but.before.planting.corn,.the.oats.were.killed.with.an.application..of.glyphosate..

ResultsThere.was.no.significant.difference.in.yield.among.treatments.in.both.studies.in.2012..In.fact,.yields.were.nearly.identical.within.both.trials.(Table.2)..However,.this.data.represents.only.one.year,.and.long.term.results.of.a.study.such.as.this.should.be.considered.before.conclusions.are.drawn...

Table 1. Hybrid, row spacing, planting date, planting population, previous crop, and tillage practices in the cover crop studies in 2012.


1 Harrison DKZ 6169 30 5/2/2012 Not specified Soybean No-till2 Harrison DKZ 6169 30 5/2/2012 Not specified Corn No-till

Table 2. Yield data from cover crop trials in 2012.

Yield Trial Treatments (bushels/acre) P-value

1 Cover 80.6 0.57 No cover 80.32 Cover 128.8 0.97 No cover 129.1


Cover Crop TerminationIf.a.cover.crop.grows.too.large,.it.is.difficult.to.control.and.can.rob.yield.like.a.weed.during.the.growing.season..This..negates.any.benefit.the.cover.crop.may.offer..This.is.why.the.timing.of.removal,.or.termination,.of.a.cover.crop.is.very.impor-tant..In.two.Wright.County.trials,.ISU.FARM.examined.the.effect.of.cover.crop.termination.timing.on.yield..In.trial.1,.winter.rye.was.planted.October.1,.2011,.with.7.5-inch.row.spacing..A.tankmix.of.atrazine.(16.oz/acre),.2-4D.(16.oz/acre),.and.Balance®.Flexx.(3.5.oz/acre).was.applied.March.28.or.April.18,.2012..Plant.height.was.6.inches.and.20.inches.at.the.early.and.late.herbicide.application.dates,.respectively.

In.trial.2,.winter.rye.was.planted.via.airplane.in.early.September.2011..An.application.of.glyphosate.(40.oz/acre).was.applied.on.April.4.to.one.plot,.and.in.the.other.plot,.glyphosate.(46.oz/acre).was.applied.on.April.11,.2012..The.plant.height.was..8–10.inches.and.10–14.inches.when.the.herbicides.were.applied.at.the.early.and.late.timings,.respectively..

ResultsIn.trial.1,.the.early.herbicide.application.resulted.in.greater.yields.than.the.later.application..The.results.were.similar.in.trial.2;.however,.the.significance.was.not.as.strong..Earlier.herbicide.applications.are.often.recommended.in.cover.crop.termination,.especially.when.it.comes.to.protecting.yield,.and.these.results.support.this.recommendation..

Table 3. Hybrid, row spacing, planting date, planting population, previous crop, and tillage practices in cover crop termination studies in 2012.


1 Wright DK 58-83 30 4/27/2012 36,000 Soybean No-till2 Wright DKC 53-78 RIB 30 4/23/2012 34,018 Soybean No-till

Table 4. Yield data from cover crop termination trials in 2012.

Yield Trial Termination Timing (bushels/acre) P-value

1 3/28/2012 171.1 0.03 4/18/2012 162.12 4/4/2012 144.7 0.13 4/11/2012 131.8


ProtectionCorn | Corn RootwormThe.use.of.corn.rootworm.(CRW).transgenic.traits.in.corn.hybrids.has.allowed.farmers.to.manage.CRW.without.using.soil-..applied.insecticides..However,.some.farmers.are.interested.to.see.if.there.is.an.economic.return.by.adding.a.granular.insecti-cide.when.planting.CRW-Bt.corn.

MethodsTwo.CRW.trials.were.conducted.in.Monona.County.and.one.in.Sioux.County.and.Lyon.County.in.2012..Each.trial.compared.CRW-Bt.and.non-Bt.hybrids.with.or.without.the.addition.of.an.insecticide..In.trial.1,.hybrids.used.were.DKC63-42.(VT3).and.DKC63-45.(non-BT)..In.trial.2,.hybrids.used.were.3240SSTRRLL.(SmartStax®).and.7240RR.(non-Bt)..In.trial.3,.hybrids.used.were.DKC.48-37.(VT3),.DKC.48-12.(SmartStax®),.and.DKC.48-40.(non-Bt)..The.insecticide.used.in.trials.1.and.2.was.Aztec®.2.1G.(5.8.lb/acre)..The.insecticide.used.in.trial.3.was.Force®.(4.4.oz/acre)..Insecticides.were.applied.in.furrow..Three.plants.per.plot.were.sampled.and.assessed.for.CRW.larval.injury.on.the.0–3.node.injury.scale..Trial.4.tested.the.hybrid.PO9910.AM1.(Herculex®).with.and.without.the.use.of.insecticide..However,.root.injury.ratings.were.not.taken,.so.the.effect.of.CRW.cannot.be.estimated..

ResultsIn.trial.1,.treatments.had.a.significant.effect.(P.


Table 1. Row spacing, planting date, planting population, previous crop, and tillage practices in the corn rootworm trials of 2012.

Row Spacing Planting PopulationTrial County (inch) Planting Date (seeds/acre) Previous Crop Tillage

1 Monona 38 4/24/2012 31,000 Corn Spring disk2 Monona 30 4/25/2012 32,316 Corn No-till 3 Sioux 30 5/1/2012 32,900 Corn Conventional 4 Lyon 22 4/24/2012 36,000 Corn Soil finished

Table 2. Treatments, root feeding ratings, and yield in corn rootworm trials in 2012.

Insecticide Yield** Trial Treatments (Y/N)* Root Injury Rating** (bushels/acre)

1 DKC63-42 (VT3) N 0.9 B 114.0 C DKC63-45 (non-BT)) N 1.3 A 103.3 C DKC63-42 (VT3) Y 0.3 C 142.0 A DKC63-45 (non-BT) Y 0.4 C 125.1 B2 3240SSTRRLL (SmartStax®) N 0.1 A 122.5 A 7240RR (non-BT) N 0.1 A 109.2 A 3240SSTRRLL (SmartStax®) Y 0.1 A 121.8 A 7240RR (non-BT) Y 0.1 A 109.1 A3 DKC 48-37 (VT3) N 0.1 A 118.1 B DKC 48-12 (SmartStax®) N 0.1 A 124.4 AB DKC 48-40 (non-BT) N 0.1 A 117.7 B DKC 48-37 (VT3) Y 0.1 A 120.2 B DKC 48-12 (SmartStax®) Y 0.1 A 127.6 A DKC 48-40 (non-BT) Y 0.1 A 122.2 AB4 PO9910 AM1 (Herculex®) Y — 171.3 A PO9910 AM1 (Herculex®) N — 164.4 A

*Aztec® 2.1G (5.8 lb/acre) was used in trials 1 and 2 and Force® (4.4 oz/acre) was used in trial 3.

**Values with the same letter in each trial by column are not statistically different (P


Corn | Seed TreatmentsSeveral.different.types.of.seed.treatments.are.available.to.protect.seed.and.seedlings.from.nematodes,.insect.feeding,.and.diseases..In.2012.numerous.nematode-protectant.seed.treatment.studies.were.conducted.to.examine.nematode.control.and/or.yield.protection..

Nematodes that Feed on CornPlant-parasitic.nematodes.are.microscopic.worms.that.feed.on.plants..Almost.every.nematode.that.feeds.on.corn.is.capable.of.feeding.on.many.other.plants..These.nematode.parasites.are.thought.to.be.native.to.most.Iowa.soils.and.to.have.fed.upon.native.plants.before.corn.was.grown.as.a.cultivated.crop..Population.densities.(numbers).of.most.species.of.plant-parasitic.nematodes.that.feed.on.corn.have.to.increase.to.damaging.levels.(called.damage.thresholds).before.yield.loss.occurs.

The.objective.of.these.experiments.was.to.assess.and.compare.the.nematode.population.densities.and.yields.of.corn.growing.in.plots.established.with.seeds.with.and.without.the.seed-treatment.nematode.protectants.

MethodsFour.seed.treatment.trials.measured.the.control.of.nematodes.that.feed.on.corn.and.yield.among.treatments..Three.trials..compared.corn.treated.with.Votivo®.and.untreated.seed..An.additional.trial.compared.multiple.seed.treatments..Treatments.were.Counter®,.Poncho®,.Avicta®,.CruiserMaxx®,.and.Poncho®/Votivo®..In.all.trials,.there.were.a.minimum.of.three.replica-tions.in.either.alternating.or.randomized.strips..Soil.core.samples.were.taken.from.each.plot.at.planting.and.at.V6.corn.growth.stage.during.the.growing.season..Nematodes.that.feed.on.corn.were.extracted.from.the.samples,.identified,.and.counted.by.personnel.in.Greg.Tylka’s.lab.at.Iowa.State.University..Additional.trial.information.can.be.found.in.Table.1..ResultsSeveral.different.species.of.nematodes.were.recovered.in.each.trial..The.most.abundant.nematode.found.in.these.trials.was..the.spiral.nematode,.followed.by.the.lesion.nematode.(Tables.2.and.4)..Nematode.population.densities.did.not.exceed.any.established.economic.threshold.in.any.study..Also,.there.were.no.differences.in.nematode.population.densities.between..treatments.(P.>.0.05)..

Yield.responses.to.the.nematode-protectant.seed.treatments.varied..In.trial.1,.the.seed.treatment.did.not.positively.effect.yield.and.actually.had.smaller.yields.associated.with.it.(Table.3)..In.trial.2,.plots.planted.with.treated.seed.had.greater.yields.than.compared.to.the.untreated.control..In.trial.3,.yields.of.plots.treated.with.Votivo®.averaged.greater.than.the.untreated.control.plots;.however,.statistically,.they.were.the.same..Finally,.in.trial.4.where.five.different.seed.treatments.were.compared,.there.were.no.differences.in.yield.between.treatments..Yields.ranged.from.200.to.about.214.bu/acre.

Though.there.were.some.yield.differences.detected.in.the.Votivo®.treated.seed,.we.cannot.say.it.was.because.of.nematode.control.since.nematode.populations.did.neither.vary.between.treatments.nor.exceed.economic.thresholds..There.may.be.other.factors.in.play.such.as.normal.field.variation.or.insect.larva.control.with.the.seed.treatment.


Table 1. Hybrid used, row spacing, planting date, planting population, previous crop, and tillage practices in the nematode- protectant seed treatment trials of 2012.


1 Cass Channel 212-17 VT3 30 5/18/2012 36,000 Corn Conventional 2 Mills Fontanelle 8 V 567 30 5/5/2012 33,000 Soybean No-till 3 Boone PO488 MM/LL/RR2 30 5/9/2012 33,000 Corn No-till4 Story Pioneer 832 30 5/11/2012 35,000 Soybean Conventional

Table 2. Nematode sampling data in nematode-protectant seed treatment trials in 2012.

Trial Treatments Spiral Planting V6 Spiral V6 Lesion Planting Lesion V6 Other Planting* Other V6*

1 Votivo® 23.0 46.5 3.0 6.5 2.5 2.5 Control 18.0 34.5 1.0 6.0 0.0 5.5 2 Votivo® 43.3 65.3 15.3 9.3 2.0 2.7 Control 60.7 70.7 8.0 20.0 14.0 4.7 3 Votivo® 41.0 29.0 3.3 2.7 0.0 23.8 Control 51.2 25.5 4.8 1.7 0.0 28.8

*Nematodes in this column are a combination of various species, such as Tylenchus, dagger, and stunt nematodes, none of which were at or above any established thresholds.

Table 3. Yield data of nematode-protectant seed treatment trials in 2012.

Trial Treatments Votivo® Yield Control Yield P-value

1 Votivo® 99.5 111.9 0.102 Votivo® 201.2 185.1 0.073 Votivo® 142.0 127.7 0.15

Table 4. Nematode and yield data in a seed treatment nematode control study in Story County in 2012.

Yield Trial Treatments Spiral at Planting Spiral at V6 (bushels/acre) P-value

4 Counter® 45.7 59.0 212.9 A 0.30 Poncho® 27.0 106.0 202.4 A Avicta® 16.0 55.0 213.6 A CruiserMaxx® 27.7 80.7 200.2 A Poncho® + Votivo® 13.3 67.7 201.6 A



Seed Treatment and Amendment StudiesFour.other.nematode-protectant.seed.treatment.trials.were.conducted.in.2012..No.disease.or.pest.control.data.were.collected.in.these.studies,.so.it.is.not.known.if.diseases,.insects,.or.pests.have.led.to.differences.in.yield.among.treatments..

MethodsAll.trials.compared.treated.seed.with.an.untreated.control..The.types.of.treatments.varied.by.trial..In.trials.1.and.2,.Avicta®.and.Poncho®/Votivo®.were.used,.respectively,.and.are.nematode-protectant.and.insecticide.seed.treatments..In.trial.3,.seed.was.treated.with.Amplify-D®,.which.is.labeled.as.an.emergence.aid..And.in.trial.4,.seed.was.treated.with.SabrEx™,.a.root.inoculant..Background.information.for.each.trial.can.be.found.in.Table.5.

ResultsNone.of.the.seed.treatments/amendments.showed.evidence.of.improving.yields.in.these.studies.(see.Table.6).

Table 5. Seed amendment and inoculant trial data from 2012.


1 Monona Renze 3240SS 30 4/25/2012 32,316 Soybean No-till2 Sioux 1081 SC 30 4/23/2012 34,000 Soybean Fall disk, rotary3 Monona LG 2515HXLL 30 4/23/2012 32,316 Soybean No-till4 Monona LG 2515HXLL 30 4/23/2012 32,316 Soybean No-till

Table 6. Yield seed amendment and trial data in 2012.

Treated Yield Control Yield Trial Treatments (bushels/acre) (bushels/acre) P-value

1 Avicta® 104.8 109.8 0.0092 Poncho®/Votivo® 233.1 233.6 0.823 Amplify-D® 149.4 147.6 0.744 SabrEx™ 150.6 147.6 0.58


Corn | FungicideAn.application.of.fungicide.to.corn.has.become.a.popular.input.with.many.farmers.in.Iowa..The.effect.of.fungicide.on.corn.yield,.however,.can.vary.from.year.to.year..Annual.corn.fungicide.trials.offer.insight.into.how.fungicides.perform.each.year..Environmental.conditions,.such.as.rainfall.and.temperature,.are.likely.the.main.factors.for.differences.in.how.a.fungicide.affects.corn.yield.since.these.factors.influence.disease.development.and.crop.growth.and.development..Since.environmental.conditions.vary.from.one.year.to.the.next,.it.is.difficult.to.predict.how.and.when.to.use.a.fungicide..Compilation.of.trial.data.over.many.years.could.help.identify.factors.associated.with.fungicide.response.in.corn.

In.2012,.there.were.15.on-farm.trials.in.Iowa.that.evaluated.the.effect.of.fungicide.on.corn..Furthermore,.an.additional.two.trials.evaluated.fungicide.application.methods.

MethodAll.fungicide.trials.examined.a.range.of.timings.and.products..Eight.trials.examined.applications.of.fungicide.at.growth-stage.R1.against.an.untreated.control..Five.trials.examined.the.application.of.fungicide.at.V6.against.an.untreated.control..One.trial.examined.the.application.of.fungicide.at.planting.against.an.untreated.control,.and.one.trial.compared.the.application.of.Headline®.at.V6.followed.by.an.application.of.Headline®.AMP.at.R1.against.an.untreated.control..Fungicide.products.used.in.these.studies.included.Headline®,.Headline®.AMP,.and.Quilt.Xcel®..All.trials.had.a.minimum.of.three.replications..See.Table.1.for.more.information.on.field.data.and.Table.2.for.rates.

ResultsOver.all.15.trials,.only.two.showed.evidence.of.fungicide.application.affecting.yield..In.trials.that.examined.the.effect.of.an.R1.application,.two.of.eight.showed.a.fungicide.resulted.in.greater.yield.(+2.2.and.+6.1.bu/acre).than.the.control.(P..0.10).that.application.of.fungicide.impacted.yield..

In.all.trials.in.which.a.fungicide.was.applied.at.V6.alone,.there.was.no.evidence.(P.>.0.10).of.an.effect.on.yield..Similarly,.when.a.fungicide.was.applied.at.planting,.there.was.no.effect.on.yield..Moreover,.in.the.trials.in.which.application.at.V6.was.followed.by.an.application.at.R1,.no.effect.on.yield.was.observed.

Most.fungal.pathogens.require.a.significant.amount.of.available.moisture.in.order.to.sporulate.and.infect.a.leaf..In.2012,..Iowa.suffered.from.severe.drought,.limiting.the.available.moisture.for.not.only.crops.but.also.fungal.pathogens..Thus,.disease.severity.was.very.low.relative.to.previous.years..In.the.absence.of.foliar.disease,.there.was.likely.little.justification.to.apply.a.fungicide.to.protect.yield..


Table 1. Hybrid, row spacing, planting date, planting population, previous crop, and tillage practices in ISU-FARM corn fungicide trials in 2012.

Row Spacing Planting Planting Population Previous Trial County Hybrid (inch) Date (seeds/acre) Crop Tillage

1 Lyon PO461AMXR 30 4/24/2012 Variable rate Soybean Strip till 34–38,000 2 Osceola Pioneer PO115 AM1 30 5/19/2012 Variable rate Soybean Strip till 36–37,000 3 Plymouth Pioneer PO528 AM1 30 5/1/2012 34,500 Corn Spring cultivated 4 Lyon DKC 5066/Pioneer 9917 22 5/7/2012 Variable rate Corn Disked— soil finished 5 Lyon Pioneer 34F07 20 4/26/2012 35,000 Soybean Soil finisher 6 Lyon Stine 9531VT3 20 4/26/2012 35,000 Soybean Soil finisher 7 Plymouth Pioneer PO528 AM1 30 5/1/2012 34,500 Corn Spring Field cultivated 8 Sioux P0636HR 30 4/26/2012 32,900 Soybean Spring disk 9 Sioux 35F50AMR 30 4/26/2012 32,900 Soybean Spring disk10 Cherokee DeKalb 5509 RIB 30 5/10/2012 34,200 Soybean Soil finisher11 Hancock DeKalb 52-62 RR 30 4/23/2012 35,000 Corn Conventional12 Floyd Mycogen 2K595 RA 30 5/11/2012 34,000 Soybean Conventional13 Sioux Pioneer 9910 AM1 30 4/25/2012 32,900 Soybean Spring disk14 Sioux Pioneer 36V53 30 4/25/2012 32,900 Soybean Spring disk15 Plymouth Pioneer PO528 AM1 30 5/1/2012 34,500 Corn Spring cultivated

Table 2. Time of application, fungicide product, application rate, and mean yield data for ISU FARM fungicide corn trials in 2012.

Rate Application Yield (bushels/acre) Trial Fungicide (oz/acre) Timing Fungicide Non-treated Control Response P-value

1 Headline® 4.0 Planting 171.0 170.3 0.7 0.32 2 Headline® 6.0 V6 162.5 159.9 2.6 0.47 3 Headline® 6.0 V6 178.3 184.7 –6.4 0.51 4 Headline® 6.0 V6 192.3 195.0 –2.7 0.41 5 Headline® 6.0 V6 181.4 186.4 –5.0 0.07 6 Headline® 6.0 V6 175.8 172.0 3.8 0.47 7 Headline® 6.0 R1 183.7 184.7 –1.0 0.80 8 Quilt Xcel™ 10.0 R1 196.2 194.6 1.8 0.6 9 Quilt Xcel™ 10.0 R1 188.0 181.9 6.1 0.00810 Headline AMP™ 10.0 R1 222.3 220.1 2.2 0.0611 Headline AMP™ 10.0 R1 171.9 169.9 3.4 0.2012 Headline AMP™ 10.0 R1 152.9 148.3 4.6 0.1713 Quilt Xcel™ 10.5 R1 187.0 181.5 5.5 0.4114 Quilt Xcel™ 10.5 R1 194.3 192.5 1.8 0.7415 Headline® 6.0 V6 182.0 184.7 –2.7 0.66 Headline AMP™ 10.0 R1


Application MethodTwo.on-farm.trials.were.conducted.in.2012.to.compare.aerial.and.ground.application.methods.for.fungicides..Headline®.

fungicide.was.applied.at.a.rate.of.6.oz/acre.in.both.trials..Aerial.fungicide.was.applied.at.110.mph.(3.gal/acre;.40.psi),.while.ground.applications.utilized.either.a.Hagie.284.or.John.Deere.6000.at.5.5.mph.(15.gal/acre;.40.psi)..An.untreated.control.was.included.in.both.trials,.and.trials.had.at.least.three.replications.

ResultsThere.was.no.evidence.of.an.effect.of.fungicide.application.on.yield.in.either.trial.in.2012..Foliar.disease.in.2012.was.very.low.due.to.the.severe.drought..The.use.of.fungicide,.regardless.of.the.application.method,.was.not.beneficial.to.yield.in.these.trials.

Table 3. Hybrid, row spacing, planting date, planting population, previous crop, and tillage practices in ISU-FARM trials that compared aerial and ground applications of fungicides on corn in 2012.


1 Osceola DeKalb 5378 30 5/1/2012 35,000 Soybean Field cultivated2 Lyon PO453 20 4/23/2012 34,300 Corn Fall disk-spring soil finish

Table 4. Application data and yield results for fungicide corn trials in 2012.

Yield* Trial Application Timing Fungicide Method (bushels/acre) P-value

1 R1 Headline® Aerial 197.9 A 0.07 Ground 207.1 A Control 200.4 A2 R1 Headline® Aerial 153.9 A 0.78 Ground 161.1 A Control 160.5 A



Corn | Goss’s WiltAfter.nearly.three.decades.of.Iowa.being.free.from.Goss’s.wilt,.the.disease.was.found.statewide.in.2011..In.2012,.various.trials.examined.how.to.control.Goss’s.wilt.using.genetics.and.chemical.control.

Goss’s Wilt-Resistant HybridsCorn.hybrids.that.have.been.selected.for.partial.resistance.to.Goss’s.wilt.are.available.in.Iowa..Two.trials.compared.Goss’s.wilt-.resistant.and.-susceptible.hybrids..In.both.trials,.the.resistant.hybrid.used.was.DKC.5655AR2.and.the.susceptible.hybrid.was.DKC.5509.RIB..Trial.1.had.Procidic.applied.at.growth-stage.R1.(14.oz/acre).to.both.treatments,.and.trial.2.had.none..Both.strip.trials.were.conducted.in.Sioux.County.(Table.1).

ResultsDifferences.in.yield.were.not.detected.among.treatments.in.either.study..The.p-values.for.trial.1.and.trial.2.comparisons.were.0.28.and.0.60,.respectively.(Table.2)..Goss’s.wilt.was.not.found.in.either.trial,.which.may.help.explain.why.there.were.no..differences.between.treatments..Goss’s.wilt.primarily.spreads.during.severe.storms,.and.there.were.very.few.in.the.2012.grow-ing.season..

Table 1. Hybrid, row spacing, planting date, previous crop, and tillage practices from two Goss’s wilt resistance trials in Sioux County in 2012.


1 Sioux Treatment 30 4/24/2012 32,900 Soybean Spring disk2 Sioux Treatment 30 4/24/2012 32,900 Soybean Spring disk

Table 2. Yield data from two Goss’s wilt resistance trials in Sioux County in 2012.


Trial Treatment Resistant Susceptible P-value

1 DKC 5655 AR2 184.4 187.9 0.282 DKC 5509 RIB 192.7 196.9 0.60

ProcidicProcidic.(a.i.:.citric.acid.3.5%).is.available.for.chemical.control.of.Goss’s.wilt..In.two.trials,.the.control.of.Goss’s.wilt.by..Procidic.(14.oz/acre).was.measured.against.an.untreated.control..Hybrids.used.were.DKC.5655.AR2.(resistant).and..DKC.5509.RIB.(susceptible).in.trials.1.and.2,.respectively.(Table.3)..


ResultsThere.was.no.evidence.that.the.application.of.Procidic.helped.improve.yields..The.p-values.for.trials.1.and.2.were.0.27.and.0.57,.respectively.(Table.4)..No.Goss’s.wilt.was.found.in.either.trial.regardless.of.treatment.

Table 3. Hybrid, row spacing, planting date, previous crop, and tillage practices from two Procidic trials in Sioux County in 2012.


1 Sioux DKC 5655 AR2 (Resistant) 30 4/24/2012 32,900 Soybean Spring disk2 Sioux DKC 5509 RIB (Susceptible) 30 4/24/2012 32,900 Soybean Spring disk

Table 4. Yield data from two Procidic trials in Sioux County in 2012.


Trial Treatment Treatment Control P-value

1 Procidic 184.4 192.7 0.272 Procidic 187.9 196.9 0.57

Citric Acid Rates and TimingIn.the.final.study.on.Goss’s.wilt.in.2012,.multiple.application.rates.and.dates.of.citric.acid.were.compared.with.an.untreated.control..The.three.citric.acid.treatments.used.were.(1).3.5%.citric.acid.(6.oz/acre).applied.on.May.25;.(2).3.5%.citric.acid..applied.on.May.25.(6.oz/acre).and.July.17.(14.oz/acre);.and.(3).4.5%.citric.acid.(14.oz/acre).applied.on.July.17..The.final.treatment.(4).was.an.untreated.control..This.trial.was.conducted.in.Wright.County.(Table.5).

ResultsThe.untreated.control.(147.4.bu/acre).had.the.greatest.corn.yields.in.this.trial.but.was.not.significantly.different.from.the.other.treatments..Thus,.there.was.no.benefit.to.applying.citric.acid..Like.the.previous.studies,.Goss’s.wilt.was.not.found.in.any.of..the.plots.

Table 5. Hybrid used, row spacing, planting date, planting population, previous crop, and tillage practices in the Goss’s wilt and citric acid studies of 2012.


1 Wright DKC 4812 RIB 30 4/25/2012 36,000 Corn Conventional

Table 6. Goss’s wilt severity and yield of Goss’s wilt resistance and citric acid trials in 2012.

Yield* Trial Treatment Rate Application Date (bushels/acre) P-value

1. 1. 6 oz/acre 5/25/2012 127.2 A 0.22 .. 2. 6 and 14 oz/acre 5/25/2012, 7/17/2012 128.6 A . 3. 14 oz/acre 7/17/2012 138.9 A 4 Control None 147.4 A



ProductionSoybean | Planting TrialsPlanting.soybean.at.the.right.time.and.population.can.make.the.difference.between.record-breaking.yields.or.having.to.replant...In.2012,.there.were.many.reported.deficiencies.when.planting.too.early.or.too.late..Factors.such.as.soil.moisture.and.soil..temperature.should.be.considered.when.planting..Other.factors.may.impact.how.decisions.are.made.around.planting.rate,.row.width,.and.planting.date..In.2012,.two.studies.looked.at.planting.rate,.one.study.looked.at.row.width,.and.three.studies.looked.various.planting.dates.

Planting Date

MethodsThree.soybean.planting.date.studies.were.conducted.in.2012..Two.trials.were.located.in.Monona.County.and.a.third.in..Dallas.County..The.first.two.trials.were.simple.comparisons.of.an.“early”.and.“late”.planting.date..Dates.chosen.were.May.1.and.May.14..Trial.3.compared.two.varieties.at.April.12.and.May.18.planting.dates.

ResultsPlots.planted.early.(May.1).had.greater.yields.than.the.plots.planted.late.by.10.6.and.9.2.bu/acre.in.trial.1.and.2,.respectively..In.trial.1,.the.differences.between.treatments.were.statistically.significant..However,.differences.in.trial.2.were.not.as.strong.statistically.and.may.have.resulted.from.field.variation..

In.trial.3.where.planting.date.X.variety.was.examined,.yields.were.approximately.all.the.same.with.the.exception.of.one.treat-ment..The.April.12.planting.of.93Y60.soybeans.had.an.average.yield.of.35.5.bu/acre.and.was.statistically.different.from.the.remaining.three.treatments..The.average.yields.of.the.three.remaining.treatments.ranged.from.43.1–46.7.bu/acre...


Table 1. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices of planting date studies of 2012.

Row Spacing Planting Population Trial County Variety (inch) (seeds/acre) Previous Crop Tillage

1 Monona Renze 82992RRcn 30 139,000 Corn No-till2 Monona Renze 82992RRcn 30 139,000 Corn No-till3 Dallas Varied 30 155,500 Corn Conventional

Table 2. Spring stand and yield of planting studies.

Spring Stand


Trial Treatments (plants/acre) Early Late P-value

1 May 1 105,415 65.0 54.4 0.09 May 14 105,815 2 May 1 96,510 60.1 51.9 0.16 May 14 100,188

Table 3. Treatments and yield of a planting date X variety trial conducted in Dallas County in 2012.

Yield*Trial Planting Date Variety (bushels/acre) P-value

3 April 12 Pioneer 93Y13 45.8 A 0.04 April 12 Pioneer 93Y60 35.5 B May 18 Pioneer 93Y13 46.7 A May 18 Pioneer 93Y60 43.1 A


Planting Population

Methods Two.trials.tested.how.differing.planting.populations.affected.yield..The.first.trial.was.conducted.in.Sioux.County.and..compared.planting.populations.of.123,000,.150,000,.and.174,000.seeds/acre..The.second.trial.was.conducted.in.Lyon.County.and.compared.planting.populations.of.125,000.and.150,000..Other.trial.information.can.be.found.in.Table.4.

ResultsPlanting.population.did.not.have.a.significant.effect.on.yield.in.either.trial.(Table.5)..

Table 4. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the planting rate studies of 2012.

Row Spacing Planting Population Trial County Variety (inch) Planting Date (seeds/acre) Previous Crop Tillage

1 Sioux Pioneer 91Y90 30 5/10/2012 Treatment Corn Conventional disk2 Lyon Pioneer 92Y57 22 5/14/2012 Treatment Corn Fall ripped— spring field finish


Table 5. Yields of planting studies in 2012.

Spring Stand Yield* Trial Treatments (plants/meter) (bushels/acre) P-value

1 123,000 111,667 67.8 A 0.56 150,000 125,833 66.7 A 174,000 146,833 67.9 A 2 125,000 94,167 67.5 A 0.82 155,000 117,000 68.1 A


Soybean Row Spacing

MethodsOne.trial.in.Sioux.County.was.conducted.testing.the.yield.differences.of.planting.soybeans.at.15-.or.30-inch.row.spacing.(Table.6)..

ResultsIn.this.study,.planting.soybeans.at.a.row.spacing.of.15.inches.resulted.in.a.yield.increase.when.compared.with.planting..30-inch.rows..The.yield.response.was.4.6.bu/acre.(Table.7)..

Table 6. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the planting rate studies of 2012.


1 Sioux Pioneer 91Y90 30 5/10/2012 30,000 Corn Spring disk conventional

Table 7. Yield and stand of soybean row spacing trial in 2012.

Spring Stand Yield Trial Treatments (plants/meter) (bushels/acre) P-value

1 15” row spacing 111,833 68.9 0.01 30” row spacing 113,667 62.3


Soybean | Land RollingLand.rolling.is.the.practice.of.pulling.a.large,.heavy.roller.across.soybean.fields.in.order.to.push.down.rocks,.smooth.the..surface.of.the.field,.and.help.break.up.residue..The.purpose.is.to.protect.harvest.equipment.that.could.be.vulnerable.to.rocks.and.corn.roots,.thus.saving.money..Yields.also.are.expected.to.improve.by.creating.a.more.uniform.harvest.

MethodsEight.land.rolling.trials.were.conducted.in.2012..The.design.of.experiments.is.simple..Plots.are.either.land.rolled.or.they.are.not.rolled..Individual.trial.information.can.be.found.in.Table.1.

ResultsOnly.two.of.the.eight.trials.showed.evidence.of.improved.yields.due.to.land.rolling..In.trial.3,.land.rolling.improved.yields.by.6.3.bu/acre,.while.in.trial.6,.yields.were.improved.by.1.9.bu/acre..As.with.many.production.strategies,.field.to.field.variation.is.expected,.and.a.farmer.should.only.do.what.works.in.their.fields..Land.rolling.is.still.fairly.new.to.Iowa.and.there.is.more.to.be.learned.about.this.practice.

Table 1. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the land rolling studies of 2012.


1 Sioux Pioneer 91Y90 30 5/16/2012 150,543 Corn Spring disk2 Osceola Kruger 2002 30 5/11/2012 156,000 Corn All disked, spring field3 Lyon Asgrow 1931 30 5/7/2012 145,000 Corn Strip till4 Osceola NK20Y2 30 5/25/2012 140,000 Corn Fall chisel, spring disk5 Osceola Pioneer 92Y12 30 5/23/2012 140,000 Corn No-till6 Hancock Asgrow 2232 30 5/14/2012 160,000 Corn Conventional7 Boone Asgrow 2031 30 5/11/2012 ??? Corn Conventional8 Buena Vista Stine 22RC62 36 5/20/2012 125,000 Corn Fall chisel- spring cultivated

Table 2. Yield and stand counts of land rolling studies in 2012.


Trial Land Rolled Control P-value

1 64.3 63.4 0.122 54.5 55.2 0.243 60.0 53.7 0.064 56.0 54.8 0.395 57.0 56.2 0.316 48.2 46.3 0.037 75.2 75.4 0.768 43.7 42.6 0.15


Soybean | SulfurSulfur.(S).fertilizer.applications.can.offer.yield.increases.where.S.deficiencies.are.present..The.objective.of.these.trials.was.to.evaluate.potential.for.S.deficiency.and.grain.yield.response.in.soybean.to.S.applications..

MethodsIn.2012,.two.trials.with.no.manure.history.were.chosen.in.western.Iowa.to.participate.in.these.trials..Calcium.sulfate..(gypsum).was.broadcast.on.strip.plots.as.the.S.source..The.S.rate.was.15.lb.S/acre.

ResultsNeither.trial.had.a.yield.response.to.the.S.fertilizer.

For.further.information.on.these.trials.and.other.research.on.sulfur.fertilization,.please.contact.John.Sawyer,.professor,..Department.of.Agronomy,.Iowa.State.University.Extension.and.Outreach.([email protected])..Table 1. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the sulfur studies of 2012.


1 Osceola Pioneer 92Y51 30 4/5/2012 140,000 Corn No-till2 Monona LG 3445 NRR 30 4/23/2012 138,000 Corn No-till

Table 2. Yield data and other measurements of sulfur trials in 2012.


Trial Application Date Treatments Sulfur Control P-value

1 4/5/2012 0 52.4 50.2 0.30 15 2 5/14/2012 0 63.3 64.3 0.43 15


Soybean | Micronutrients and Foliar FeedingMicronutrients

MethodsSix.side-by-side.micronutrient.trials.were.conducted.on.soybean.in.2012..The.treatments.were.a.mixture.of.boron,.zinc,.and.manganese.and.an.untreated.control..The.mixture.was.one.part.Winfield®.Max-in.ZMB.(1.qt/acre).and.one.part.Max-in.Boron.(0.5.pt/acre).applied.in.15.gallons.of.water/acre..Nutrient.samples.were.collected.from.soil.and.plant.tissue.to.monitor.micro-nutrient.changes.after.foliar.fertilizer.was.applied..All.samples.were.sent.to.Iowa.State.University.for.processing.by.Antonio.Mallarino..All.trials.were.replicated.at.least.three.times.

ResultsThe.application.of.micronutrients.was.not.seen.to.be.beneficial.in.these.trials.in.2012..These.fields.may.not.have.soil.nutrient.deficiencies.and.thus.do.not.need.the.micronutrient.fertilizer.applications.

For.further.information.on.these.trials.and.other.information.regarding.micronutrient.research,.please.contact.Antonio..Mallarino,.professor,.Iowa.State.University.Extension.and.Outreach.([email protected]).

Table 1. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the micronutrients studies of 2012.


1 Sioux Pioneer 92Y22 30 5/11/2012 150,000 Corn Conventional2 Osceola Pioneer 92Y51 30 5/18/2012 140,000 Corn No-till3 Lyon Producers 2408 30 5/10/2012 161,000 Corn Disk ripped fall- field cultivated spring4 Worth AgVenture 20A3RR 30 5/17/2012 140,000 Corn Conventional5 Hancock Dyna-Gro 36RY-1.9 30 5/10/2012 150,000 Corn Conventional6 Hancock Pioneer 92Y51 30 5/16/2012 155,000 Corn Conventional

Table 2. Yield results from micronutrient feeding trials in 2012.

Trial Treatments Treatment Yield Control Yield P-value

1 Micro Mix 64.8 63.8 0.712 Micro Mix 45.7 46.2 0.613 Micro Mix 50.6 49.6 0.384 Micro Mix 41.3 42.1 0.565 Micro Mix 36.7 37.3 0.836 Micro Mix 56.7 55.8 0.18


Foliar Feeding

MethodsOne.trial.in.Boone.County.was.set.up.to.investigate.the.use.of.Cobra®.and.foliar.fertilizers.to.increase.the.number.of.soybean.branches.while.shortening.the.space.between.nodes.through.the.use.of.Cobra®,.and.then.restart.growth.with.the.use.of.the.foliar.fertilizer..Cobra®.was.used.at.a.rate.of.12.oz.per.acre.June.2.followed.by.Awaken®/Bio-Forge®.treatment.applications.two.weeks.later..Awaken®.and.Bio-Forge®.were.used.at.a.rate.of.16.oz.per.acre..

ResultsThere.were.no.significant.yield.differences.between.foliar.feeding.treatments.in.2012..There.were.slightly.more.nodes/plant.in.plots.treated.with.Cobra®,.Awaken®,.and.Bio-Forge®..However,.that.number.was.not.significant.at.alpha.0.05..The.result.is.the.same.for.branching.

Table 3. Trial information from a foliar feeding trial conducted in Boone County in 2012.


1 Boone Pioneer 93Y13 30 5/11/12 155,000 Corn Conventional

Table 4. Plant height, nodes, and yield results from a foliar feeding trial in 2012.

Plant Height* Yield Trial Treatments (centimeters) Nodes/Plant Branching (bushels/acre) P-value

1 Control 88.3 A 14.6 2.8 42.3 0.18 Awaken® 84.1 B 14.8 2.8 42.5 Cobra®, Awaken®, Bio-Forge® 81.2 C 15.1 3.0 44.1

*Measurements with the same letter within a column are not significantly different from each other (alpha = 0.05).


ProtectionSoybean | Seed TreatmentsSeed.treatments.offer.vital.protection.to.germinating.seeds.and.developing.seedlings.from.fungi,.insects,.and.nematodes..In.2012,.12.trials.explored.the.use.of.seed.treatments.to.help.protect.from.yield-robbing.diseases.and.insects..

MethodsTrials.1–6.compared.the.insecticide-fungicide.seed.treatment.CruiserMaxx®.against.an.untreated.control..Other.seed.treatments.tested.were.Acceleron™.IX409.(trial.7),.Trilex®-Allegiance®-Gaucho®.(trial.8),.Gaucho®-Trilex®-PPST.2020-PPST.120+.(trial.9),.and.GraphEx™.(trials.10–12)..In.trial.2,.Endigo®.insecticide.was.applied.across.all.treatments..In.trial.3,.Quilt.Xcel®.and.Endigo®.were.applied.across.all.treatments..

ResultsThe.use.of.a.seed.treatment.on.soybean.had.mixed.results.in.2012..Two.CruiserMaxx®.trials.(2.and.4).showed.significant.(P.


Table 1. Variety used, row spacing, planting date, planting population, previous crop, and tillage practices in the seed treatment studies of 2012.


1 Sioux NK25R3 30 5/10/2012 150,543 Corn Spring disk 2 Sioux NK25R3 30 5/10/2012 150,543 Corn Spring disk 3 Sioux NK25R3 30 5/10/2012 150,434 Corn Spring disk 4 Sioux NK25R3 30 5/10/2012 150,434 Corn Spring disk 5 Monona Renze 2889RR 30 5/4/2012 139,000 Corn No-till 6 Monona Renze 2889RR 30 5/4/2012 139,000 Corn No-till 7 Osceola Asgrow 1631 30 5/18/2012 150,000 Corn Disk ripped- fall cultivated 8 Sioux Pioneer 91Y90 30 5/10/2012 150,543 Corn Conventional disk 9 Lyon Pioneer 92Y31 22 5/11/2012 135,000 Corn Disked spring- field cultivated10 Monona LG C 3031RR 30 5/9/2012 139,000 Corn No-till11 Crawford Renze 2442RR2 15 — — Corn Disk-field cultivated12 Crawford Renze 2442RR2 15 — — Corn Disk-field cultivated

Table 2. Yield and other results from seed treatment trials in 2012.


Trials Treatments Treatment Control P-value

1 CruiserMaxx® 57.4 53.5 0.11 2 CruiserMaxx® 52.3 45.1 0.004 3 CruiserMaxx® 62.3 61.9 0.72 4 CruiserMaxx® 60.6 56.9 0.09 5 CruiserMaxx® 65.0 60.1 0.15 6 CruiserMaxx® 53.8 51.9 0.20 7 Acceleron™ IX409 52.6 51.0 0.12 8 Trilex®-Allegiance®-Gaucho® 66.2 65.6 0.19 9 Gaucho®-Trilex®-PPST 2020-PPST 120+ 61.2 57.0 0.0210 GraphEx™ 48.8 47.7 0.4711 GraphEx™ 37.1 33.5 0.000512 GraphEx™ 35.4 34.8 0.41


Soybean | Fungicide and White Mold TrialsFungicide.applications.have.become.more.popular.among.soybean.farmers.in.recent.years..The.primary.use.of.fungicides.has.been.to.control.diseases.such.as.Septoria.brown.spot,.Cercospora.leaf.blight,.and.white.mold..With.higher.grain.prices,.the.return.on.production-related.investments.is.more.easily.achieved..However,.there.are.risks.involved.when.applying.fungicides.during.times.when.disease.severity.is.low,.including.minimal.economic.gains.and.increased.chance.of.fungicide.resistance.in.the.pathogen.population..

General Use Fungicides

MethodsIn.2012,.eight.trials.(Table.1).examined.the.use.of.fungicides.to.control.foliar.disease..In.trials.1–4,.Stratego®.YLD.was.applied.at.V6..In.trials.5–8,.either.PriaxorTM.or.Headline®.was.applied.at.R3..In.trial.8,.Tundra®.(5.oz/acre).and.chlorpyrifos.(8.oz/acre).were.applied.to.treated.plots.in.addition.to.PriaxorTM.and.was.compared.to.an.untreated.control..Trials.that.used.Stratego®.YLD.were.conducted.in.partnership.with.Heartland.Cooperative..A.final.trial.was.conducted.to.compare

ISU FARM Research Report - Iowa State University · ISRF12-99 February 2013 2012 ISU FARM Research...

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Transcript of ISU FARM Research Report - Iowa State University · ISRF12-99 February 2013 2012 ISU FARM Research...