Bill JohnsonUniversity of Missouri

A Decision Support System for Weed Management

University of Nebraskaand

North-Central Partner States

ObjectiveObjective• Develop a biology and

economics based weed management decision support tool for crop managers

Development TeamDevelopment Team

• Weed Scientists

• Information systems specialist

• Listening group-Users

WeedSOFT Partner States

IllinoisIllinois MichiganMichiganIndianaIndiana MissouriMissouriKansasKansas NebraskaNebraska

WisconsinWisconsin

WeedSOFTWeedSOFT

Bioeconomic DecisionBioeconomic Decision

Groundwater VulnerabilityGroundwater VulnerabilityGroundwater Risk AssessmentGroundwater Risk Assessment

Weed IdentificationWeed Identification

EnviroFXEnviroFXSite and product specific assessment of groundwater contamination risk

MapVIEWMapVIEWColor coded county maps depicting vulnerability of groundwater to contamination

WeedVIEWWeedVIEWVisual images as an aid in weed identification

AdvisorAdvisorComputes crop yield and dollar loss based

on weed density, weed free yield and

crop price

Weed Management StrategiesWeed Management Strategies

• Cultivation

• Pre herbicide

• Post herbicide

• Combined strategies

Treatment Selection CriteriaTreatment Selection Criteria

• Geographical restrictions• Soil properties• Rotational crop• Ground and surface water

restrictions• Crop and weed growth stage

ADVISORADVISOREvaluation of pre,

post, pre+post weed management strategies in five crops:

corn, sorghum, soybeans, sugarbeets, wheat

State Specific Parameters

HerbicidesHerbicides Soil Properties Soil PropertiesHerbicide EfficacyHerbicide Efficacy Rotational Restrictions Rotational RestrictionsApplication Rates Application Rates Geographical Restrictions Geographical Restrictions Weed Species Weed Species Weed Competitive Index Weed Competitive Index

Input application informationInput application information

Input crop informationInput crop information

Input environmental informationInput environmental information

Input weed informationInput weed information

OutputOutput

• Ranking of strategies based on net return or yield

• Detailed economic and efficacy analysis of treatments

• Change in weed seed bank with each treatment

Treatment Ranking and AnalysisTreatment Ranking and Analysis

Seedbank change

WeedSOFT as a WeedSOFT as a Teaching ToolTeaching Tool

Biological FactorsBiological Factors• Crop and weed species competitiveness• Influence of crop and weed growth

stage on crop-weed interference• Influence of crop row spacing on crop

competitiveness• Influence of precipitation on herbicide

efficacy and rotational crop risk

17.2/40 = 43%

Corn, Weed free yield = 150 bu/ACorn, Weed free yield = 150 bu/A

Soybeans, Weed free yield = 40 bu/ASoybeans, Weed free yield = 40 bu/A

17.5/150 = 12%

Crop Species CompetitivenessCrop Species Competitiveness

Corn 0-5” height; weed free yield = 150 bu/ACorn 0-5” height; weed free yield = 150 bu/A

17.5/150 = 12%

8.9/150 = 6%

Weed Species CompetitivenessWeed Species Competitiveness

Common cockleburCommon cocklebur

Redroot pigweedRedroot pigweed

Corn 0-5” height; Weed free yield = 150 bu/ACorn 0-5” height; Weed free yield = 150 bu/A

17.5/150 = 12%

Weed Competitiveness Based on Weed HeightWeed Competitiveness Based on Weed Height

Cocklebur 2-4” heightCocklebur 2-4” height

Cocklebur 4-8” heightCocklebur 4-8” height25.1/150 = 17%

Corn 0-5” heightCorn 0-5” height

17.5/150 = 12%

Weed Competitiveness Based on Crop HeightWeed Competitiveness Based on Crop Height

11.4/150 = 7.6%

Corn 6-12” heightCorn 6-12” height

Corn weed free yield = 150 bu/ACorn weed free yield = 150 bu/A

Soybeans 1st trifoliate; weed free yield = 40 bu/ASoybeans 1st trifoliate; weed free yield = 40 bu/A

Weed Competitiveness Based on Row SpacingWeed Competitiveness Based on Row Spacing

30” Row Spacing30” Row Spacing

7.5” Row Spacing7.5” Row Spacing

12.1/40 = 30%

9.9/40 = 25%

Corn 0-5”; Weed free yield = 150 bu/ACorn 0-5”; Weed free yield = 150 bu/ACocklebur 2-4”Cocklebur 2-4”

Herbicide Efficacy Based on MoistureHerbicide Efficacy Based on Moisture

Moisture StressedMoisture Stressed

Excellent MoistureExcellent Moisture

77.9%77.9%

% Control

100%100%

% Control

Corn 0-5”; weed free yield = 150 bu/ACorn 0-5”; weed free yield = 150 bu/ACocklebur 2-4”Cocklebur 2-4”

Cultivation Efficacy Based on MoistureCultivation Efficacy Based on Moisture

Moisture StressedMoisture Stressed

Excellent MoistureExcellent Moisture

72.4 %72.4 %

54.9 %54.9 %

% Control

% Control

Missouri WeedSOFTMissouri WeedSOFT• Decision Support System• Teaching/Learning Tool• Available in 2002 on CD-Rom

–Initial price $195–Yearly updates will be $35-50

• WeedSOFT website–http://weedsoft.unl.edu

Missouri WeedSOFTMissouri WeedSOFT• To order:

–Make checks payable to WeedSOFT 2002

–Send to : Bulletins, P.O. Box 830918, Lincoln, NE 68583-0918

WeedSOFTWeedSOFTA State Specific Decision Support System for Weed

Management