Slide Presentation

TITLE    (click title to view slides)
Corn Weed Control Update - 2021

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

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• PowerPoint - 13.5 MB
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TABLE OF CONTENTS
  1. Weed Control in Field Corn 2021
  2. Herbicide Carryover or Soil pH
  3. Field Corn Yield Loss (%) Caused by Uncontrolled Weeds in UGA Weed Science Research Trials (2007-2020)
  4. Field Corn Weed Control Questions for you?
  5. A general plan of attack?
  6. Herbicide Timing Effects on Spray Coverage - 2020
  7. Herbicide Timing Effects on Spray Coverage in Field Corn - 2020
  8. Herbicide Timing Effects on Spray Coverage (%) in Field Corn - 2020
  9. Roundup + Atrazine + Prowl Works Great For Me But . . .
  10. Field Corn Weed Control - 2020
  11. Texas Panicum Control in Field Corn - 2020 (49 DAT)
  12. Does POST Applied Prowl Cause Field Corn Yield Loss???
  13. Field Corn Weed Control - 2020
  14. Laudis 3.45SC @ 3 oz/A + Atrazine 4L @ 64 oz/A + Dual Magnum 7.62EC @ 16 oz/A + MSO @ 1% v/v
  15. Field Corn Weed Control - 2020
  16. Field Corn Weed Control - 2020
  17. Field Corn Weed Control - 2020 Roundup + Liberty????
  18. Field Corn Weed Control - 2020 Roundup + Liberty????
  19. New(er) Products Being Tested
  20. Sinate - 2020
  21. Impact Core - 2020
  22. Impact Core 7.15EC @ 40 oz/A + Atrazine 4L @ 32 oz/A + Induce @ 0.25%v/v + AMS @ 2.5 lb/A
  23. Acuron GT - 2020
  24. Shieldex - 2020
  25. Field Corn Lay-By (16 GPA, 30 PSI, 3.7 MPH, Floodjet TK-VS2)
  26. Post-Harvest Palmer Amaranth Populations Must be Managed!
  27. Palmer Amaranth Burndown - 2019 (AMAPA 1-6" tall)
  28. Tropical Spiderwort/Benghal Dayflower (TSW/BD) After Corn Harvest
  29. Post-Harvest Control of TSW/BD with 2 Applications (14 d apart) of Gramoxone (paraquat)
  30. Questions/Comments?



SLIDE CONTENTS
  1. Eric P. Prostko, Ph.D. Professor/Extension Weed Specialist Dept. Crop & Soil Sciences Weed Control in Field Corn 2021
  2. Herbicide Carryover or Soil pH Soil pH = 4.7
  3. Field Corn Yield Loss (%) Caused by Uncontrolled Weeds in UGA Weed Science Research Trials (2007-2020). Treated vs. Non-treated 200 Bu/A X 0.34 X $4.00 = $272/A What about harvest? What about next year?
  4. Field Corn Weed Control Questions for you? What technologies are you planting? RR, LL, Conventional, Enlist (2,4-D)? Do you need Counter? Is atrazine still working for you on pigweed? Lets assume it does not What will be planted after the field corn?
  5. A general plan of attack? MUST START CLEAN! Use 1 qt/A of Atrazine 4L PRE (or Dual II Magnum, or Warrant, or Outlook) Follow up with a timely POST program (V3-V5 stage) that includes an additional 1.5 qt/A of Atrazine 4L Roundup + Atrazine probably not good enough anymore! Lots of options depending upon how you answered previous questions? Liberty, Laudis, Impact/Armezon, Halex GT, Callisto, Acuron, dicamba, 2,4-D
  6. Herbicide Timing Effects on Spray Coverage - 2020 CN-06-20 Miller Co. 30 DAP April 16 JD 4630 90’ boom length 20” nozzle spacing 10 GPA 32 PSI 11 MPH 8003EVS Roundup + Atrazine + Quest + Grounded
  7. Herbicide Timing Effects on Spray Coverage in Field Corn - 2020 2’” 2” 6” 6” CN-06-20 JD 4630, 90’ Boom 20” Nozzle Spacing 10 GPA, 32 PSI 11 MPH 8003EVS Nozzles V4: 9-10” tall 20 DAP V6: 14-16” tall 30 DAP
  8. Herbicide Timing Effects on Spray Coverage (%) in Field Corn - 2020 (LSD 0.10 = 2.1) (LSD 0.10 = 2.1) CN-06-20, Miller Co. JD 4630, 90’ Boom 20” Nozzle Spacing 10 GPA, 32 PSI 11 MPH, 8003EVS Nozzles -39.6% Spray Card Height (in) %
  9. Roundup + Atrazine + Prowl Works Great For Me But………. CN-08B-20 May 21 23 DAT Roundup P-Max II @ 32 oz/A Atrazine 4L @ 64 oz/A Prowl H2O @ 32 oz/A Applied 19 DAP NTC
  10. Field Corn Weed Control - 2020 CN-14-20 May 15 10 DAT NTC Roundup P-Max @ 32 oz/A Atrazine @ 64 oz/A Prowl H20 @ 32 oz/A Applied 26 DAP
  11. Texas Panicum Control in Field Corn – 2020 (49 DAT) LSD 0.10 = 9.2 CV = 8.89 Source: C. Cahoon (NCSU) Applied 38 DAP, V5 stage Control (%) Treatment
  12. Does POST Applied Prowl Cause Field Corn Yield Loss??? LSD 0.10 = NS CV = 12.32 LSD 0.10 = 27.9 CV = 7.2 LSD 0.10 = NS CV = 10.6 LSD 0.10 = NS CV = 8.98 Bu/A
  13. Field Corn Weed Control - 2020 CN-07B-20 May 18 39 DAP NTC Roundup P-Max II @ 32 oz/A Laudis @ 3 oz/A Atrazine @ 64 oz/A Prowl H20 @ 32 oz/A Applied 19 DAP
  14. Laudis 3.45SC @ 3 oz/A + Atrazine 4L @ 64 oz/A + Dual Magnum 7.62EC @ 16 oz/A + MSO @ 1% v/v CN-02-20 April 21 7 DAT
  15. Field Corn Weed Control - 2020 CN-09B-20 May 21 22 DAT Halex GT @ 58 oz/A Atrazine 4L @ 32 oz/A Induce @ 0.25% v/v AMS @ 2.5% v/v Applied 20 DAP
  16. Field Corn Weed Control - 2020 CN-07B-20 May 18 20 DAT NTC Impact 2.8SC @ 1 oz/A MSO @ 1% v/v AMS @ 3 lb/A Applied 19 DAP
  17. Field Corn Weed Control – 2020 Roundup + Liberty???? PE-15-20 May 21 23 DAT
  18. Field Corn Weed Control – 2020 Roundup + Liberty???? PE-15-20 June 16 68 DAP
  19. New(er) Products Being Tested Sinate (glufosinate + topramezone) AMVAC Impact Core (topramezone + acetochlor) AMVAC Acuron GT (bicyclopyrone + s-metolachlor + mesotrione + glyphosate) Syngenta Shieldex (topyralate) Summit Agro USA
  20. Sinate - 2020 CN-07B-20 May 18 21 DAT NTC Sinate 2.57SL @ 21 oz/A Atrazine 90DF @ 9 oz/A MSO @ 1% v/v AMS @ 3 lb/A Applied 19 DAP
  21. Impact Core - 2020 CN-07B-20 May 18 21 DAT NTC Impact Core 7.15EC @ 30 oz/A Atrazine 4L @ 32 oz/A NIS @ 0.25% v/v AMS @ 2.5 lbs/A Applied 19 DAP
  22. Impact Core 7.15EC @ 40 oz/A + Atrazine 4L @ 32 oz/A + Induce @ 0.25%v/v + AMS @ 2.5 lb/A CN-07B-20 April 30 2 DAT
  23. Acuron GT - 2020 CN-10B-20 May 21 22 DAT Acuron GT 4.29SC @ 60 oz/A Induce @ 0.25% v/v Applied 20 DAP
  24. Shieldex - 2020 CN-14-20 May 27 47 DAP NTC Bicep Lite II Magnum 6SC @ 53 oz/A (PRE) Shieldex 3.33SC @ 1 oz/A (26 DAP) Atrazine 4L @ 16 oz/A (26 DAP) Agridex @ 1% v/v (26 DAP)
  25. Field Corn Lay-By (16 GPA, 30 PSI, 3.7 MPH, Floodjet TK-VS2)
  26. Post-Harvest Palmer Amaranth Populations Must be Managed!
  27. Palmer Amaranth Burndown - 2019 (AMAPA 1-6” tall) NC-01-19 May 30 10 DAT NTC Gramoxone 3SL @ 32 oz/A Tricor 4L @ 8 oz/A Induce @ 0.25% v/v
  28. Tropical Spiderwort/Benghal Dayflower (TSW/BD) After Corn Harvest (need tillage and/or 2 apps of Gramoxone or 2,4-D or Aim)
  29. Post-Harvest Control of TSW/BD with 2 Applications (14 d apart) of Gramoxone (paraquat) 1 week after POST2
  30. Questions/Comments?