Resistance Management Spray Like You Mean It! Optimize each - PDF document

5/2/2018 R ESISTANCE MANAGEMENT FOR E NLIST AND X TEND C ROP S YSTEMS Bryan Young CPDA 2018 A & I Conference – San Antonio Resistance Management  Spray Like You Mean It!  Optimize each application for efficacy  Integrate diverse, effective herbicide sites of action  Multiple factors limit implementation  Use non-chemical weed control methods Weed Science 1

5/2/2018 https://www.youtube.com/watch?v=9U5Z1MLMFAU http://cropwatch.unl.edu/2017/spraying-new-phenoxy-herbicide-formulations-xtend-and-enlist-soybeans Weed Science Drift Reduction Agents (DRAs) Polymer composition:  Polyvinyl  Polyacrylamide  Hydroxypropyl guar ***Increase the viscosity of the spray solution*** Weed Science 2

5/2/2018 GPA for Dicamba in 2018 XTENDIMAX + ROUNDUP POWERMAX TTI11004 @ 40 PSI 10 GPA 15 GPA 20 GPA 12 MPH 8 MPH 6 MPH 3

5/2/2018 XMAX + PMAX + “water conditioner” + COC + INTACT TTI11004 @ 40 PSI 10 GPA 15 GPA 20 GPA 12 MPH 8 MPH 6 MPH XMAX + PMAX + SELECTMAX + WARRANT + INTACT TTI11004 @ 40 PSI 10 GPA 15 GPA 20 GPA 12 MPH 8 MPH 6 MPH 4

5/2/2018 Greater than 6” Good Luck! 4-6” 2” 3-4” Marginal Ideal Good Weed Science Spray Like You Mean It!  Ultra Coarse droplets from nozzles w/wo DRAs are required for Xtend systems to manage physical spray drift.  Can be used for effective weed management, but are prone to reduced weed control if spray coverage is compromised  Will NEVER optimize herbicide efficacy  Increasing the carrier volume to 15 or 20 GPA can regain spray coverage.  Ultimately, the spray requirements for Xtend system are not ideal for herbicide activity which hastens the evolution of weed resistance to herbicides. Weed Science 5

5/2/2018 Herbicide-Resistant Weed Era Challenging, Fragile, Expensive Weed Science Mechanisms of Herbicide Resistance  Target Site  Altered binding site (DNA point mutation)  Gene amplification for target site  Non-Target Site Express different levels of weed  Metabolism resistance to herbicides  Compartmentalization  Reduced translocation Increase in low-level resistance mechanisms Weed Science 6

5/2/2018 Weed Science Current/Future Soybean Traits MGI Soybean Weed Science 7

5/2/2018 Current/Future Soybean Traits MGI Soybean Weed Science Herbicide Program Evaluation Based on # of Herbicide Site of Action Groups Crop: Soybean (Dicamba; RR2Y Xtend) Target Weeds: Marestail (glyphosate-resistant) Waterhemp (ALS/PPO/glyphosate-resistant) Herbicide Program Group # # Effective on Waterhemp Glyphosate + 2,4-D - Burndown 9, 4 not applicable followed by Glyphosate + Xtendimax + 9, 4, 3 Fierce XLT - PRE 2, 14, 15 followed by Glyphosate + Engenia + Zidua - 9, 4, 15 2 POST Total for program 5 3 Weed Science 8

5/2/2018 Integrate Diverse, Effective Herbicide Sites of Action  Cost, complexity, and marketing programs limits adoption of this strategy  False sense by farmers that a single herbicide can ‘fix’ resistance  Over-reliance on POST herbicides has allowed for the evolution of low-level resistance mechanisms  Major need for soil residual herbicides!!! Weed Science Use Non-Chemical Weed Control Methods 9

5/2/2018 Resistance Management  Spray Like You Mean It!  Optimize each application for efficacy  Integrate diverse, effective herbicide sites of action  Multiple factors limit implementation  Use non-chemical weed control methods Weed Science Resistance Management  Spray Like You Mean It!  Optimize each application for efficacy  Integrate diverse, effective herbicide sites of action  Multiple factors limit implementation  Use non-chemical weed control methods  Advantage when new traits allow for multiple effective POST herbicides? Weed Science 10

5/2/2018 Resistance Management  Spray Like You Mean It!  Optimize each application for efficacy  Integrate diverse, effective herbicide sites of action  Multiple factors limit implementation  Use non-chemical weed control methods  Advantage when new traits allow for multiple effective POST herbicides? Maybe Weed Science 11