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Certified Crop Advisor Training January 22, 2002 Macon, Georgia

Almost Everything You Want to Know About Stink Bugs and What You Better Know about Roundup Ready Cotton. Certified Crop Advisor Training January 22, 2002 Macon, Georgia. Insecticide Applications per Acre Georgia Cotton, 1986-2001. Boll Weevil Era.

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Certified Crop Advisor Training January 22, 2002 Macon, Georgia

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  1. Almost Everything You Want to Know About Stink Bugs and What You Better Know about Roundup Ready Cotton Certified Crop Advisor Training January 22, 2002 Macon, Georgia

  2. Insecticide Applications per AcreGeorgia Cotton, 1986-2001 Boll Weevil Era --Active BWEP-- (does not include BWEP sprays) --Boll Weevil Free----------------------- low populations ---------Bt Cotton-------- Beltwide Cotton Conferences

  3. Ten fields per county. 5 Bollgard and 5 Non-Bt Fields had cutout Collected 100 bolls per field. Approximately 50 bolls collected from two locations. Sampled all harvestable bolls from individual plants. Examined bolls for insect damage. Worm Damage Bug Damage Insecticide application history. Target Pest(s) Survey MethodsInsect Boll Damage Survey: Georgia 2001 Counties Surveyed: Appling, Brooks, Bulloch, Burke, Colquitt, Decatur, Dooly, and Terrell

  4. Green bolls examined internally. Bolls with at least one lock with significant rot were considered damaged. Worm Damage Bug Damage Survey Methods

  5. Percent “Bug” and Larval Damaged BollsInsect Boll Damage Survey: Georgia 2001 39 Bollgard and 43 Non-Bt Fields

  6. Complex of “Bugs” may feed on developing bolls. Percent “Bug” Damaged BollsInsect Boll Damage Survey: Georgia 2001 ** Prob |t| <0.01 39 Bollgard and 43 Non-Bt Fields

  7. Mean Insecticide ApplicationsInsect Boll Damage Survey: Georgia 2001 2.52 ** 1.22 ** Prob |t| <0.01 37 Bollgard and 42 Non-Bt Fields

  8. Stinkbug “Complex” • Predominant species include Southern Green Stink Bug and Brown Stink Bug • Other true bugs such as Tarnished Plant Bug and Leaf Footed Bugs cause similar damage • There are predaceous species such as the Spine Soldier Bug

  9. Southern Green Stink Bug

  10. Brown Stink Bug

  11. Striped Leaf Footed Bug

  12. Bug Damage--What Does it Look Like? • Fruit abortion • Hawk-billed bolls • External boll punctures • Internal boll punctures, warts • Internal rot

  13. Misshapen or hawk-billed bolls result from poor pollination or poor seed development in one or more locks.

  14. Bug feeding can result in external punctures. These sites serve as a means of pathogen entry into the developing boll. External sites do not always indicate internal entry or punctures.

  15. Internal damage initially appears as warty growth (within 24 hr). Discoloration and rot proceeds to a single seed, lock, or throughout the entire boll.

  16. Stink Bug Threshhold • Depend on reliable scouting procedures • They are shy, mobile creatures • What is damage? • Adjacent crop has significant impact • Best approach: Boll DAMAGE Count

  17. Aren’t they shy!

  18. Cotton / Peanut Interface

  19. When should we spray?

  20. J. Greene, summary of 5 locations ab a abc bc c +109 +93 +66 +32 0 appl 4.2 Bidrin 2.0 Bidrin 0.6 Bidrin 1.0 Bidrin $20.90* $48.48* $34.61* $10.89* *Net= $0.60/lb - $8.31/appl

  21. “Bug” Threshold • When 20% of medium sized bolls (the diameter of a quarter) display internal signs of feeding and stink bugs are observed. OR • Treat when stink bugs number 1 per 6 row feet.

  22. Stink Bug Control

  23. Stink Bug Trial 2000Irwin County GA - Tyler

  24. Stink Bug Trial 2000Irwin County GA - Tyler Treated July 27

  25. 2 row cotton plots in peanuts. Stink Bug Field TrialLang Rigdon Farm - 2001 14.33 4 DAT 3.33 0.67 LSD (p=0.05) 4.4 Treated Sept 2

  26. Southern Green vs. BrownInsecticide Susceptiblity Pyrethroids Bidrin methyl parathion Vydate OP’s Bidrin methyl parathion Orthene Pyrethroids are weak on Brown Stink Bug

  27. When does a boll reach the point that it will not suffer damage from bugs? About 25 days

  28. Top 12 Varieties and Technology in 2001 GA Crop

  29. Top 12 Varieties in 2001 GA Crop

  30. Technology Distribution (%) of 2000 vs 2001 GA Crop

  31. Roundup Ready Cotton Issues • Variety performance • Mechanism of crop “tolerance” • Weed management programs • TIMING of applications

  32. RR Cotton Variety Performance • Glyphosate (properly applied) does not affect the yield of RR cultivars • In terms of yield potential, RR cultivars are not superior • Conventional, Bollgard/RR, and Bollgard varieties outperform RR varieties

  33. In variety trials in high yield environments, RR varieties are rarely in the top 20 percent.

  34. RR Cotton Mechanism of Crop Tolerance • A genetically altered enzyme system provides tolerance to glyphosate in the production of shikimic acid (amino acids) • Glyphosate is not degraded within the plant • Excellent vegetative tolerance but marginal tolerance in developing flower • Can sterilize pollen

  35. Roundup Ready Weed Management... there are many, many options.

  36. Roundup Ready Programs

  37. RR Cotton Weed Management--Reasons to Include Conventional Herbicides in Program • Reduce potential for early competition • Improve control spectrum • Reduce selection pressure for weed shifts and resistance • Avoid phantom fruit loss with (mis) directed applications

  38. Not Precise Enough!

  39. Timing is Everything!

  40. 4-Leaf Cotton

  41. 5-Leaf Cotton Too Late?

  42. Not Precise Enough!

  43. Precision is critical with directed applications of glyphosate in RR cotton!

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