Herbicide And Adjuvant Tank Mixes With Glyphosate For Weed .

Herbicide and Adjuvant TankMixes With Glyphosate ForWeed ControlCurtis R. Thompson and Dallas E. PetersonKansas State University

Introduction All glyphosate labels recommend theaddition of ammonium sulfate (AMS)– Ties up cations that could interact with theglyphosate molecule– Lowers spray solution pH Several products (AMS replacements)are available to applicators

Objectives Evaluate AMS and AMS replacements onglyphosate efficacy Evaluate the effect of carfentrazone and2,4-D formulations on glyphosate efficacy

Methods Experiments were established, three nearManhattan and two near Garden City,Kansas All control rating are based on visualevaluations 2 wk (Garden City) or 4 wk(Manhattan) after application.

Materials & Methods Manhattan, 3 experiments Spray Volume: 15 gpa Water Hardness: 103 mg/L Total Hardness asCaCO3 6 grains/gal Application:7/1, 7/17/12/05– Velvetleaf:6-10”6-12”– Sorghum:18”16”– Corn:24”20”– Sunflower:12-18”12-16”– Crabgrass2-4”--

Materials & Methods Garden City, 2 experiments Spray Volume: 10 gpa Water Hardness: 140 mg/L Hardness as CaCO3 8gr/gal Application:Experiment 17/18/05, 70F, 78% RHExperiment 27/22/05, 68 F, 82% RHPalmer amaranth: 2 to 6-in3 to 8-invol. wheat:4 to 4.5-lf3.5 to 4-lf

Results AMS replacement evaluations

Weed control with ammonium sulfate replacements andglyphosate evaluated 2 WAT, Garden City (Experiment 1).TreatmentRatePAAMVWHT------- (% control) ------0.38 lb ae74100N PAK AMS5% v/v97100Class Act NGAllianceChoiceRequestDestinyGuardian2.5% v/v1.25% v/v0.5% v/v0.5% v/v2.5% v/v0.25% v/v9089607485721001001001001001007NSRoundup WMax :LSD (0.05)

Weed control with glyphosate plus AMS replacementadjuvants at 4 WAT, Manhattan, KS (Experiment 2).TreatmentRoundup WMax :AMSClass Act NGAllianceChoiceRequestSpeedwayBlendmasterUS 500CitronN-TankLSD (5%)Rate0.28 lb ae2 % w/w2.5% v/v1.25% v/v0.5% v/v0.5% v/v0.5% v/v1% v/v0.25% v/v2.2 lb/100G0.5% v/vVelvetSunleafSorghum Corn flower---------------(% 97979892951006

Weed control with glyphosate plus AMS replacementadjuvants at 4 WAT, Manhattan, KS (Experiment 3).TreatmentRoundup WMax :AMSClass Act NGAllianceChoiceRequestSpeedwayBlendmasterUS 500CitronN-TankLSD (5%)Rate0.28 lb ae2 % w/w2.5% v/v1.25% v/v0.5% v/v0.5% v/v0.5% v/v1% v/v0.25% v/v2.2 lb/100G0.5% v/vVelvetSunleafSorghum Corn flower---------------(% 7585807078907

Roundup WeatherMax0.28 oz ae

Roundup WeatherMax AMS0.28 oz 2 % w/w (17 lb/100 gal)

Roundup WeatherMax Class Act NG0.28 oz 2.5 % v/v

Roundup WeatherMax Alliance0.28 oz 1.25 % v/v

Roundup WeatherMax Choice0.28 oz 0.5% v/v

Roundup WeatherMax Request0.28 oz 0.5 % v/v

Roundup WeatherMax Citron0.28 oz 2.2 lb/100 gal

Results Effect of carfentrazone and 2,4-Dformulations on glyphosate

Weed control with adjuvants, glyphosate andcarfentrazone (Experiment 2).CornerstoneRatePAAMVWHT------- (% control) ------Cornerstone 0.28 lb ae76760.007 lb80610.25% v/v7876Aim EW Pref 0.007lb 0.25%7961Pref Interlock7882NS11Aim EWPreferenceLSD (5%)0.25% 4 oz

Glyphosate, Class Act NG, and 2,4-D tank mixesfor large crabgrass control, Manhattan Exp1.90LSD807060None2,4-D LV6Unison50403020100Rdp Org MaxGlyStaPluTcdn IQGlyphosate at 0.28 lb ae/a Class Act NG 2.5% v/v

Glyphosate, Class Act NG, and 2,4-D tank mixesfor weed control, Manhattan Experiment 1.1009080706050403020100None2,4-D LV6UnisonVelvetleafSorghumCornSunflowerGlyphosate at 0.28 lb ae/a Class Act NG 2.5% v/v

Glyphosate, Class Act NG, and 2,4-D tank mixesfor weed control, Manhattan Experiment rghumCornGlyphosate at 0.28 lb ae/a Class Act NG 2.5% v/v

Summary The addition of AMS to glyphosate enhanced weedcontrol compared to glyphosate applied alone. Choice, Request, Speedway, Blendmaster, US 500,and Citron tank mixed with glyphosate did notprovide equal control to glyphosate AMS. Class Act NG, Alliance, and N-Tank provided similarcontrol to AMS when added to glyphosate. The addition of carfentrazone reduced volunteerwheat control with glyphosate. The addition of Unison antagonized grass controlwhile all 2,4-D formulations increase broadleaf weedcontrol with glyphosate.

K-State Research and ExtensionKnowledgeforLIFEQuestions

Roundup WMax : 0.38 lb ae 74 100 LSD (0.05) 7 NS Guardian 0.25% v/v 72 100 Destiny 2.5% v/v 85 100 Request 0.5% v/v 74 100 Choice 0.5% v/v 60 100 Alliance 1.25% v/v 89 100 Class Act NG 2.5% v/v 90 100 N PAK AMS 5% v/v 97 100 Treatment Rate PAAM VWHT. Weed control with glyphosate plus AMS replacement .