Slide Presentation

TITLE    (click title to view slides)
Weed Control in Conventional Soybeans: "Back to the Future"

AUTHOR
Eric P. Prostko
Professor and Extension Weed Specialist
University of Georgia

DOWNLOAD PRESENTATION    (right click and select 'Save Target As...')
• PowerPoint - 6.1 MB
• PDF - 3.1 MB

TABLE OF CONTENTS
  1. Weed Control in Conventional Soybeans: "Back to the Future"
  2. Weed Control in Conventional Soybeans
  3. PPO-Resistance in US
  4. PPO-Resistance in GA
  5. Palmer Amaranth Response to Valor PRE.
  6. Valor in GA Soybeans?
  7. "Old School"
  8. Top Herbicides Used in Georgia Soybeans (1995) (330,000 acres planted)
  9. Top 10 Troublesome Weeds in Georgia Soybeans (1995)
  10. Conventional Soybeans Herbicides
  11. NON-GMO Soybean Cultivars with STS and Metribuzin Tolerance????
  12. Metribuzin Products
  13. Anthem Max, Dual, Warrant, Zidua, Outlook, Prowl????
  14. Soybean Weed Control - 2021
  15. Soybean Weed Control - 2021
  16. Reflex @ 24 oz/A + Classic @ 0.5 oz/A + 2,4-DB @ 2 oz/A - Applied 17 DAP (V2)
  17. Classic 25DG @ 0.67 oz/A + NIS Injury on Non-STS Soybeans
  18. PPO Injury on Soybean
  19. Envive Rates/Crop Injury
  20. Soybean Injury Caused by Envive 41.3WG @ 3.5 oz/A 10 DAP
  21. Surveil 48WDG
  22. Sonic 70WG
  23. Conventional Soybeans POST Grass Control
  24. Narrow Rows and Weed Control - Soybeans
  25. On-Time
  26. Conventional Soybean Weed Control - Summary (assuming no PPO resistance)
  27. Questions/Comments



SLIDE CONTENTS
  1. Weed Control in Conventional Soybeans: “Back to the Future” Eric P. Prostko Extension Weed Specialist Dept. Crop & Soil Sciences
  2. Weed Control in Conventional Soybeans All depends upon the development and spread of PPO resistance (WSSA MOA #14)!
  3. PPO-Resistance in US First identified in US in 2002 tall waterhemp (Illinois) 24 reported cases 4 weed species tall waterhemp, Palmer amaranth, common ragweed, goosegrass 1 recently confirmed case in GA Source: Heap, I. The International Herbicide-Resistant Weed Database. Online. Friday, December 3, 2021 . Available www.weedscience.org Copyright © 1993- 2021 WeedScience.org All rights reserved.
  4. PPO-Resistance in GA 240 oz/A Source: Randell and Culpepper, 2021
  5. Non-treated control Valor PRE Susceptible Population Valor PRE PPO POST Resistant Population Palmer Amaranth Response to Valor PRE. UGA Tifton Greenhouse - 2021
  6. Valor in GA Soybeans? Effective, legal and labeled but……. Valor fb Reflex/Prefix/Warrant Ultra is a good weed control program but a bad resistance mgt plan! Unless you hand-weed escapes! Weed control in cotton and peanut without Valor/Reflex?
  7. “Old School” What were you doing before 1996? What weeds were causing you problems before 1996?
  8. Top Herbicides Used in Georgia Soybeans (1995) (330,000 acres planted) Source: NASS – Agricultural Chemical Usage – Field Crops and Potatoes (03/25/96) Acres (%)
  9. Top 10 Troublesome Weeds in Georgia Soybeans (1995) sicklepod annual MG pigweed coffee senna cocklebur Johnsongrass crabgrass Texas panicum FL beggarweed yellow nutsedge Source: Proceeding SWSS (1995) 48:299
  10. Conventional Soybeans Herbicides PPO resistant weeds = SOL (really!) Metribuzin – PRE Prowl or Group 15’s Reflex, Cobra, Ultra Blazer, Prefix, Warrant Ultra Classic or FirstRate (sicklepod + MG) STS® (1993) - single gene (non-GMO) Bolt™ (2015) - 2 genes (non-GMO)
  11. NON-GMO Soybean Cultivars with STS and Metribuzin Tolerance???? GoSoy 48C17S Root-knot susceptible Virtue 4520S, 4921S, V4720S Root-knot susceptible
  12. Metribuzin Products
  13. Anthem Max, Dual, Warrant, Zidua, Outlook, Prowl????
  14. Soybean Weed Control - 2021 SB-01-21 May 18 29 DAP NTC Metribuzin @ 0.25 lb ai/A + WSSA Group 15 (PRE)
  15. Soybean Weed Control - 2021 SB-04-21 July 19 53 DAP NTC Reflex 2SL @ 24 oz/A Classic 25DG @ 0.5 oz/A 2,4-DB 2SL @ 2 oz/A Induce @ 0.25% v/v Applied 17 DAP
  16. Reflex @ 24 oz/A + Classic @ 0.5 oz/A + 2,4-DB @ 2 oz/A - Applied 17 DAP (V2) SB-04-21 June 16 30 DAP
  17. Classic 25DG @ 0.67 oz/A + NIS Injury on Non-STS Soybeans WT-01-21 July 19 6 DAT
  18. PPO Injury on Soybean
  19. Envive Rates/Crop Injury Corteva 41.3% WG Classic – 9.2% Valor – 29.2% Harmony – 2.9% Rate range of 2.5-4.0 oz/A I prefer 2.5 oz/A Similar injury situation occurs with Valor XLT Valor XLT = Valor (30%) + Classic (10.3%) Most likely cause is Classic STS/Bolt technologies??
  20. Soybean Injury Caused by Envive 41.3WG @ 3.5 oz/A 10 DAP NTC Envive SB-21-11
  21. Surveil 48WDG Corteva Valor (36%) + FirstRate (12%) 2.8 to 4.2 oz/A PRE within 3 days of planting Better residual control of annual mg than Valor alone? 2.8 oz/A 2 oz/A Valor 51WG 0.4 oz/A FirstRate 84WG NTC Surveil 48WG 2.8 oz/A (PRE) 75 DAT
  22. Sonic 70WG Corteva Spartan (62.1%) + FirstRate (7.9%) PPI or PRE Cotton rotations?? NTC Sonic 70WG 3 oz/A (PRE) SB-08-13 June 16 39 DAT
  23. Conventional Soybeans POST Grass Control NTC PE-42-21 June 16 29 DAT 4’-5” weeds at application
  24. Narrow Rows and Weed Control - Soybeans “A review of row spacing experiments in which an initial weed management practice had been accomplished revealed that in 64% of the cases (72 of 113 site-years), less late-season weed density and/or biomass, or greater late-season weed control, was achieved in narrow-row (< 30”) compared to wide-row soybean production systems.” Bradley, K. W. 2006. A review of the effects of row spacing on weed management in corn and soybean. Online. Crop Management doi:10.1094/CM-2006-0227-02-RV.
  25. On-Time Works 100% of the time Excellent crop safety any GPA or nozzle tank-mix with anything no rotational restrictions FREE Obstacles Farm size Weather breakdowns Beach Vacations ???
  26. Conventional Soybean Weed Control – Summary (assuming no PPO resistance) start clean narrow rows (<30”) metribuzin + Group 15 or Prowl - PRE timely POST’s Reflex, Prefix, Warrant Ultra, Cobra, Ultra Blazer, Classic, FirstRate hand-weed escapes
  27. Questions/Comments eprostko@uga.edu www.gaweed.com