Slide Presentation

TITLE    (click title to view slides)
Cotton Weed Control Update - 2025

AUTHOR
Stanley Culpepper
Professor and Extension Weed Specialist
University of Georgia

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TABLE OF CONTENTS
  1. Cotton Weed Control Update - 2025
  2. Dicamba: In-Crop 2025
  3. Diuron
  4. Paraquat
  5. Liberty Ultra
  6. Enversa - Encapsulated Acetochlor for Cotton
  7. Palmer control with Enversa vs Warrant
  8. Axant ISO Systems Are Strong!
  9. Comparing 2,4-D Formulations. #1 Drift Issue in 2024
  10. Greatest Threats to Weed Management
  11. Step 1: Herbicides Alone Are Not Sustainable
  12. #2: Don't plant into emerged pigweed
  13. Step 3: At least two residuals effective on Palmer at plant!
  14. Residual herbicide influences Palmer population at POST1
  15. Residual herbicide influences Palmer height at POST1
  16. Step 4: Timely Postemergence Applications
  17. Weed Response to Roundup, Liberty, and Mixtures.
  18. Texas Millet Control by RU as Influenced by Dicamba
  19. Limiting antagonism from POST tank mixtures
  20. Layby is a GAME CHANGER for weed control!!!
  21. The Endangered Species Act (ESA)
  22. The Dilemma with ESA
  23. We Have Time and Can Simplify for Farmers
  24. Must Understand To Get Started
  25. It is Very Complicated, Let's Do it Together
  26. New Liberty Ultra Label - ESA Restrictions
  27. Extension Approach To Overcome Herbicide Strategy!
  28. Information Available To Help = EPA Resource Toolbox?
  29. Agronomic Crop in Georgia - Mitigation Points
  30. Agronomic Crop in Georgia - Mitigation relief points
  31. Agronomic Crop in Georgia - Field with 3% or less slope
  32. Agronomic Crop in Georgia - Sand, loamy sand or sandy loam (no hard pan)
  33. Agronomic Crop in Georgia - Cover crops (no tillage)
  34. Agronomic Crop in Georgia - Strip-till production
  35. Agronomic Crop in Georgia - Non-irrigated lands and Incorporation (center pivot or tillage)
  36. Agronomic Crop in Georgia - Grass waterway & Terrace
  37. Agronomic Crop in Georgia - Field Border of Vegetation and Mitigation Tracking
  38. Agronomic Crop in Georgia - Do you have at least 9 points?
  39. Other Options if Needed - Agronomic Crop
  40. Culpepper Farms: Fields 1- 36
  41. Culpepper Farms: Fields 37-40
  42. Impact From In-Field Drift Buffers
  43. Spray Drift Ground Application- (0 to 230 feet)
  44. Boom Height and Spray Droplet Size Impacts Pesticide Drift Distance (feet) to COTTON
  45. Spray Drift Ground Application- (0 to 230 feet)
  46. Additional Methods to Reduce Buffer
  47. Managed Areas Adjacent To Treated Field Downwind Can Represent Spray Drift Buffers
  48. Who is Responsible for Ensuring Compliance
  49. Other Critical Topics - Get The Handout
  50. UGA Extension - ESA After Training Survey, Winter 2025
  51. Science, Cooperation, & Communication



SLIDE CONTENTS
  1. Cotton Weed Control Update – 2025 Stanley Culpepper University of Georgia Tifton GA Herbicides….anything new? Cotton weed management program Preparing you for ESA compliance 1772 Woodland, NC
  2. Dicamba: In-Crop 2025 Baring politics appears to be no chance for Engenia, Tavium, or XtendiMax for 2025 – ESA Quite concerned about getting them for 2026 Section 18 has no chance Section 24 c local need label…..???? UPW only if a label is successful
  3. Diuron Diuron 2025/2026 availability good EPA/manufacturers working through risk assessment
  4. The paraquat training module is now live on Syngenta’s website.  It is available at Paraquat Training.  Links from Gramoxone 2.0 and 3.0 pages have been updated along with the EPA paraquat page.   No charge for the training English and Spanish One time registration form requiring name, email address, state, and pesticide application license number. Automatic renewal email
  5. Liberty Ultra Rate range 24-29 fl oz. May make up to 2 applications in crop or one preplant + one in crop. Emergence till early bloom Liberty Ultra 24 oz ~= Liberty at 32-36 oz. Do not exceed 58 oz for entire year
  6. PRE rate range: 1.25 to 2 quarts; optimum is 1.5 qt/A POST 1.5 quarts: after cotton is completely emerged but before it reaches first bloom Do not exceed 2 qt per application or 4 qts for year. Research is seeing major differences from Warrant as influenced by “drying” time Enversa – Encapsulated Acetochlor for Cotton
  7. Enversa Warrant 76 b 94 a Palmer control with Enversa vs Warrant Irrigation 0.4” on Day 0, 2, or 7 Irrigation Day 0 Enversa Warrant 90 b 99 a Irrigation Day 2 Enversa Warrant 94 a 99 a Irrigation Day 7 Rate for both products 48 oz/A; evaluation ~2 wk after irrigation
  8. Alite 27….. Axant ISO Systems Are Strong! Must plant tolerant cultivar (Stoneville) Little to no crop response Residual at 2.5 to 3 oz/A is very good Tank-mix needed, very broad spectrum Every other bed is treated with a tank mix partner with Axant
  9. Much Volatility Research in GA Ester Amine Choline Comparing 2,4-D Formulations. #1 Drift Issue in 2024 Sunbelt Expo
  10. Availability of economically effective pesticides is essential Greatest Threats to Weed Management Herbicide resistance Regulatory actions Three mighty challenges Weed Control Toolbox Weed Control Toolbox Economics on the farm
  11. Deep Tillage Hand Weed - eliminate seed production Step 1: Herbicides Alone Are Not Sustainable WEEDOUT POLLEN
  12. #2: Don’t plant into emerged pigweed Planting operation covers plants with dirt …. herbicides won’t kill Plant stressed from planters running…. herbicide often don’t kill Less residual to the ground….residual herbicides are key Stop and spray something like Gramoxone + Direx before running strip till rig and planting!
  13. Step 3: At least two residuals effective on Palmer at plant! Reduces selection pressure – POST Herbicides!!!!! Improves coverage POST herbicides Removes early-season competition -- often higher yield
  14. Residual herbicide influences Palmer population at POST1 2,156,220 a No PRE C19-2024; Brake 16 oz, Direx 1 pt, Reflex 12 oz, Warrant 2 pt, Alite 2.5 oz Brake+ Reflex Number per acre at 14 days, 2024 Reflex +Warrant 13612 b 7078 b Brake+ Alite 23413 b Reflex+ Direx+ Warrant 7078 b #/A All treatments 99% or better control
  15. Residual herbicide influences Palmer height at POST1 5.5 a No PRE C19-2024; Brake 16 oz, Direx 1 pt, Reflex 12 oz, Warrant 2 pt, Alite 2.5 oz Brake+ Reflex Height at 19 days, 2024 Reflex +Warrant 1.52 b 1.57 b Brake+ Alite 2.16 b Reflex+ Direx+ Warrant 1.37 b Inches
  16. Step 4: Timely Postemergence Applications Decisions made on weed size? Decisions based on weed biology? Concept of overlapping residual (key) Avoid antagonism
  17. Weed Response to Roundup, Liberty, and Mixtures. 100 a % Pink Purslane Control Liberty+RU 100 a Liberty Roundup PMAX 3 = full rate; Liberty = full rate. Goosegrass 6”; purslane 15”, crabgrass 8”. Veg 5-2024. Roundup 68 c 78 b 100 a % Goosegrass Control Liberty+RU Liberty Roundup 53 c 78 b 100 a % Large Crabgrass Control Liberty+RU Liberty Roundup 53 c 86 b
  18. 84 b % 100 a 99 a RU PMAX 32 oz + XtendiMax 22 oz RU PMAX 32 oz + XtendiMax 22 oz RU PMAX 32 oz 3” tall 10” tall 10” tall Texas Millet Control by RU as Influenced by Dicamba
  19. Smaller weed sizes, usually less than few inches Residual herbicides reducing density and size Full herbicide rates Coverage essential Sequential applications may make you money, especially with goosegrass Limiting antagonism from POST tank mixtures
  20. Layby is a GAME CHANGER for weed control!!! RU + Direx + Envoke Direx + MSMA + Envoke
  21. ESA implemented in 1973 Provides framework to conserve & protect endangered & threatened species & their habitats! The Endangered Species Act (ESA) Total of ~1600 species + 900 critical habitats!!! Grey Wolf Wood Bison Black-footed Ferret Whorled Sunflower
  22. Court removal of tools Overwhelming regulations The Dilemma with ESA
  23. Extension Consultants Retailers Manufacturers Department of Agriculture We Have Time and Can Simplify for Farmers Advisors
  24. #1 Particle drift #2 #3 Bulletins Live! Two 1. Runoff: each pesticide will be assigned a value of potential of product to runoff and damage species or habitat (0-9 points). 2. Particle Drift: each pesticide will be given a buffer drift requirement as influenced by application method (ground, airblast, airplane, etc.) 3. BLT: Website identifies if your field is in a pesticide use limitation area (PULA). Must Understand To Get Started
  25. It is Very Complicated, Lets Do it Together Particle drift Runoff 0-9 points Drift - ground 0-230 feet #1 #2 #3 Pesticide Use Limitation Area *Increase points for runoff *Increase drift buffers *Remove tool each field each field BLT!
  26. New Liberty Ultra Label - ESA Restrictions BLT avoidance area
  27. Extension Approach To Overcome Herbicide Strategy! Objective 1: Get you to 9 points for all fields to avoid runoff mitigations. Objective 2: Help you make sure you can take 230 buffer down to near 0. Objective 3: You help us understand any barriers to meet these objectives. #1 Keep in mind, we are hopeful most products require 6 points or less but there will be important exceptions! Particle drift #2
  28. Information Available To Help = EPA Resource Toolbox? Mitigation Menu Mitigation Calculator Guide Calculator is Key Advisor……KEY Farmer…not so much https://www.epa.gov/pesticides/mitigation-menu https://www.epa.gov/endangered-species/pesticides-and-endangered-species-educational-resources-toolbox EPA’s RUNOFF POINTS CALCULATOR
  29. Agronomic Crop in Georgia
  30. Agronomic Crop in Georgia
  31. Agronomic Crop in Georgia Field Slope < 3% Land leveling, laser leveling, land smoothing are approved 2 points
  32. Agronomic Crop in Georgia Predominately Sandy Soil 50% sand, loamy sand, or sandy loam without restrictive layer that impedes movement of water into the soil 2 points
  33. Agronomic Crop in Georgia Cover Crop Options – Points Tilled cover: terminated using tillage. POINTS = 1 Short duration cover: planted in fall but no active growth in spring or planted in spring. POINTS = 2 Long duration cover: planted in fall growing into spring, vegetation on field year around. POINTS = 3
  34. Agronomic Crop in Georgia Strip-till, Mulch Till, No Till: Must have 30% residue on surface Strip Till: Soil undisturbed except for strips up to 1/3rd the row width. Disc openers, coulters, row cleaners, in-row chisel can be used; cultivation emergency weed control. POINTS = 2 Mulch Till: 100% of soil surface disturbed but uniform layer or residue. POINTS = 2 No Till: Disc openers, coulters, and row cleaners but no tillage. POINTS = 3
  35. Agronomic Crop in Georgia Non-Irrigated Lands and Incorporation Non-Irrigated Lands: must not be irrigation on the land during year. POINTS = 3 Incorporation: For products not requiring incorporation, irrigation within 24 hrs or tillage moving herbicide to depth of 1” before first runoff. POINTS = 1
  36. Agronomic Crop in Georgia Grass Waterway & Terraces Waterway: Downslope of application area; regularly maintained, vegetative cover, and outlet stability; inspected regularly; no width defined. 2 Points Terraces: Stair-stepping technique creating a flat crop areas having a 3% slope or less. 2 Points
  37. Agronomic Crop in Georgia Field Border and Mitigation Tracking Field Border: strip of permanent vegetation established at the edge of the field (downslope). Maintain to eliminate or significantly reduce flow. 20-30 feet: 1 Point 30-60 feet: 2 Points >60 feet: 3 Points Mitigation tracking: Document your mitigations: 1 Point
  38. Agronomic Crop in Georgia Do you have at least 9 points?
  39. Other Options if Needed – Agronomic Crop Rate of product applied (annual max) Percent of field treated (new technologies) Exempt – managed areas 1000 foot down gradient Expert (1 point) or conservation program (2 points) 3. Water sensors with center pivot = 2 points 4. Mitigation measures from multiple categories = 1 pt Trying even harder to avoid Trying to avoid
  40. Culpepper Farms: Fields 1- 36 16
  41. Culpepper Farms: Fields 37-40 13 A few fields do not have grass waterways so when I take that away I lose multiple category mitigation as well
  42. Impact From In-Field Drift Buffers* EPA DETERMINED WORST CASE FOR GROUND RIG WILL BE 230 FEET DOWNWIND * As interpreted in the Draft Herbicide Strategy
  43. Spray Drift Ground Application– (0 to 230 feet) Low boom, coarse drops = 75% or 58 feet for worst case
  44. Boom Height and Spray Droplet Size Impacts Pesticide Drift Distance (feet) to COTTON 85 b 188 a Medium droplet 48” 24” Boom Height 68 b 36 c Ultra Coarse droplet 48” 24” Boom Height
  45. Spray Drift Ground Application– (0 to 230 feet) Low boom, coarse drops, RH = 75 + 15 + 10 = 100% or 0 feet
  46. Layby Rig: 50% Hooded: 75% Additional Methods to Reduce Buffer Broadcast Hooded: 50%
  47. Managed Areas Adjacent To Treated Field Downwind Can Represent Spray Drift Buffers *More options are available through herbicide strategy!
  48. Who is Responsible for Ensuring Compliance Department of Ag is responsible Occasional random inspection is possible Most likely when you get called in for a drift complaint
  49. Other Critical Topics – Get The Handout Goosegrass infests GA cotton Tropical spiderwort HANDOUTS: COTTON ESA Wheat Cole Crops Greens Squash Sweet Potato Watermelon
  50. Please Fill Out Survey
  51. Industry Partners Science, Cooperation, & Communication Farmers