Presented at 2011 OK Soybean Expo on January 19, 2011 in Stillwater.

1. Recipe for Success:Weed Control in 2011OK Soy Expo Joe Armstrong Extension Weeds Specialist

2. New (and “newish”) products for 2011

3. Authority XL FMC Pre-mix of Authority & Classic Use rates: 3.0 – 9.6 oz/acre Fall and PRE applications 4.0 oz = 3.33 oz Authority DF 1.25 oz Classic *36 month rotation restriction for canola

4. Warrant Monsanto Sold as MON 63410 in 2010 Use rate: 3 pints/acre Apply Early POST, V2 – V3 growth stage Tank-mix with POST product(s)

5. Verdict BASF Pre-mix of Sharpen & Outlook Use rate: 5 – 10 floz/acre Fall, burndown, and PRE applications 5.0 floz = 1 floz Sharpen 4.17 floz Outlook

6. Fierce Valent Pre-mix of Valor & pyroxysulfone Use rate: 3 – 4.5 oz/acre Fall, burndown, and PRE applications 3.0 oz = 2.0 oz Valor 1.5 ozpyroxysulfone *Not currently labeled for use in OK

7. What is the #1 goal of weed control? (Hint: it’s not always killing weeds)

8. YIELD!

9. When do weeds begin reducing yields? Adapted from Knezevic et al. (2003) Weed Tech 17:666-673

11. Less in-season weed pressure

13. PRE herbicides inno-till soybean (NW OK) glyphosate + 2,4-D alone 7 weeks after treatment All treatments included glyphosate + 2,4-D ester (32 fl oz + 1 pt)

14. PRE herbicides inno-till soybean (NW OK) glyphosate + 2,4-D alone 7 weeks after treatment All treatments included glyphosate + 2,4-D ester (32 fl oz + 1 pt)

16. Early POST with residual

17. Herbicide resistance testing update

18. Glyphosate-resistant marestail in Oklahoma Resistant Susceptible Untreated 1x glyphosate (0.75 lbae) 2x glyphosate (1.5 lbae) 4x glyphosate (3.0 lbae) Grant County, 2010

19. PSS-2779 “Diagnostic Service to Test for Herbicide-resistant Weeds in Oklahoma”www.weedscience.okstate.edu

21. Burndown before planting—start clean

22. Tank-mix to control difficult weeds

24. Contact information Joe Armstrong OSU Dept. of Plant and Soil Sciences joe.armstrong@okstate.edu Twitter: @OSUWeedSci www.weedscience.okstate.edu