Slide Presentation

TITLE    (click title to view slides)
Weed Control in Field Corn 2024

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

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TABLE OF CONTENTS
  1. Weed Control in Field Corn 2024
  2. 2023 Problems
  3. Laurens County - 2023
  4. Scanning Electron Micrograph of a Goodyear (Black/Versigard Synthetic Rubber) Hose Used 8 Times.
  5. Halex GT/Counter - 2023
  6. Counter/Herbicides
  7. Seminole County - March 2023
  8. Macon County - March 2023
  9. Bulloch County - Spring 2023
  10. Pierce County - 2023
  11. Tattnall Co. - 2023
  12. Volunteer Corn Control
  13. Dims/Fops Have Soil Residual Properties
  14. RR Corn Control (Pioneer 33M57) 40 DAT*
  15. What happens when you spray Liberty on a non-LL corn hybrid?
  16. Yellow Nutsedge in Field Corn - 2023
  17. Sandea/PRE/Counter - 2023 Don’t do it!!!!!!
  18. 2,4-D Injury in Non-Enlist Field Corn
  19. Tropical Spiderwort
  20. Tropical Spiderwort Control in Field Corn - 2005
  21. Tropical Spiderwort Control in Field Corn - 2005
  22. Tropical Spiderwort Control in Field Corn - 2005
  23. Field Corn Yield Loss (%) Caused by Uncontrolled Weeds in UGA Weed Science Research Trials (2007-2023) Treated vs. Non-treated
  24. As always...
  25. Pre-Plant Burndowns - 2023
  26. Conventional Field Corn
  27. Field Corn Weed Control - 2023 No Roundup or Liberty??
  28. Field Corn Weed Control - 2023
  29. Field Corn Weed Control - 2023
  30. Field Corn Weed Control - 2023 No Roundup or Liberty?
  31. RR and/or Liberty Systems
  32. Field Corn Weed Control - 2023
  33. Field Corn Weed Control - 2023
  34. Field Corn Weed Control - 2023
  35. Field Corn Weed Control - 2023 No Roundup or Atrazine
  36. Field Corn Weed Control - 2023 No Roundup or Atrazine
  37. New(er) Products Being Tested - I Not in UGA Pest Control Handbook (yet?)
  38. New(er) Products Being Tested - II Not in UGA Pest Control Handbook (yet?)
  39. Field Corn Weed Control - 2023
  40. Field Corn Weed Control - 2023
  41. Field Corn Weed Control - 2023 Late-Season
  42. Field Corn Weed Control - 2023
  43. Post-Harvest
  44. Post-Harvest Weed Control - 2023 Gramoxone 2SL @ 48 oz/A + Tricor 4F @ 8 oz/A + NIS @ 0.25% v/v (15 GPA, AIXR11002 nozzles, 3.5 MPH)
  45. Post-Harvest Weed Control - 2023 Gramoxone 2SL @ 48 oz/A + Tricor 4F @ 8 oz/A + NIS @ 0.25% v/v (15 GPA, AIXR11002 nozzles, 3.5 MPH)
  46. Post-Harvest Control of Tropical Spiderwort
  47. Questions/Comments



SLIDE CONTENTS
  1. Weed Control in Field Corn 2024
  2. 2023 Problems
  3. Laurens County - 2023 R. Joyce
  4. Scanning Electron Micrograph of a Goodyear (Black/Versigard Synthetic Rubber) Hose Used 8 Times.
  5. Halex GT/Counter - 2023 G. Slaughter June 20, 2023
  6. Counter/Herbicides
  7. Seminole County – March 2023 Nematodes Root-knot = 7 Lesion = 4 Stubby = 82 40 is threshold Ring = 10 Spiral = 1 R. Ethredge
  8. Macon County – March 2023 Nematodes Root-knot = 100-140 100 is threshold Stubby = 170-200 40 is threshold Lesion = 50-210 200 or more is threshold K. Brown
  9. Bulloch County – Spring 2023 * W. Tyson Planted March 24 Pioneer 1622 *Shallow planting depth (1.5”) First 7 DAP *1.52” rain *3 nights below 49 F 2022 – Peanuts ½X rate Strongarm in August *70 stubby nematodes/100 cc 40/threshold Replant showed same symptoms even after using Counter 20G INFR Oxadiazon @ 1.9 ppm + Prodiamine @ 0.08 ppm detected in soil Was impregnated on fertilizer
  10. Pierce County - 2023 pH = 5.0; P was very high; K, Mg, Ca were all low
  11. Tattnall Co. - 2023 Stine 9818-32N Possible linuron sprayer contamination Linex 4L @ 24 oz/A applied to V3-V4 (12”) tall field corn (P1197VYHR) caused a 22-32% yield reduction. Richburg et al. 2020. Weed Technology 34:277-283. 2.3 ppm of linuron was detected in tissue sample Photos: D. Bowen (May 2023)
  12. Volunteer Corn Control Best option is clethodim takes about 10 days to really work 6 day plant-back restriction yes, it’s VERY real Liberty and Gramoxone have been inconsistent (for me) RR + LL hybrids
  13. Dims/Fops Have Soil Residual Properties CN-14-23 May 26 49 DAP Assure II 0.88EC @ 24 oz/A Prime Oil @ 1% v/v Applied 1 DBP Assure II 0.88EC @ 24 oz/A Prime Oil @ 1% v/v Applied 0 DBP
  14. RR Corn Control (Pioneer 33M57) 40 DAT* NTC (123 Bu/A) SelectMax 0.97EC @ 6 oz/A Induce @ 0.25% v/v AMS X-TRA @ 2.5% v/v (0 Bu/A) Gramoxone Inteon 2SL @ 40 oz/A Atrazine 4L @ 32 oz/A Agridex @ 1% v/v (27 Bu/A) *Applied to 7” tall corn, V4 stage of growth
  15. What happens when you spray Liberty on a non-LL corn hybrid? CN-01B-16 DKC 66-59 Liberty @ 29 oz/A + Atrazine @ 48 oz/A Applied V4-V5 (6”) *Only made 28 Bu/A!!!!! *Other treatments made ~231 Bu/A *88% yield loss 6 DAT 15 DAT
  16. Yellow Nutsedge in Field Corn - 2023 Not very competitive 800/100 row ft = 10% yield loss PRE Dual lI Magnum (PRE) Only yellow POST Roundup + Atrazine + Sandea (0.67 oz/A) purple + yellow Basagran 4SL 32 oz/A + 1% COC 2 applications (7-10 days) only yellow P. Sapp - May 11, 2023
  17. Sandea/PRE/Counter – 2023 Don’t do it!!!!!! CN-04-23 April 18 19 DAP NTC Sandea @ 0.67 oz/A Sandea @ 1.34 oz/A No Counter Counter 9-15% yield loss (0.67 oz/A) 14-30% yield loss (1.34 oz/A)
  18. 2,4-D Injury in Non-Enlist™ Field Corn Rate No more than 1 pt/A Timing Not after 8” Hybrid P1289 P1608 P1633 Tank-Mixes glyphosate adjuvants
  19. Tropical Spiderwort does not like deep tillage hard to control in-season with typical programs need Group 15’s for residual Anthem Maxx, Dual Magnum, Warrant, Outlook, Zidua Halex GT/Callisto??? Lay-By 2,4-D, Aim, Evik, Gramoxone Post-Harvest 2,4-D, Aim, Gramoxone
  20. Tropical Spiderwort Control in Field Corn - 2005 Untreated Aim 2EC @ 1.5 ozs/A Dual Magnum 7.62EC @ 1.33 pt/A Herbimax @ 1% v/v 34 DAT
  21. Tropical Spiderwort Control in Field Corn - 2005 Untreated Evik 80DF @ 2 lbs/A Dual Magnum 7.62EC @ 1.33 pt/A Herbimax @ 1% v/v
  22. Tropical Spiderwort Control in Field Corn - 2005 Untreated Gramoxone Max 3SC @ 16 oz/A Dual Magnum 7.62EC @ 1.33 pt/A Herbimax @ 1% v/v
  23. Field Corn Yield Loss (%) Caused by Uncontrolled Weeds in UGA Weed Science Research Trials (2007-2023) Treated vs. Non-treated 200 Bu/A X 0.33 X $4.00 = $264/A 250 Bu/A X 0.33 X $4.00 = $330/A What about harvest? What about next year?
  24. As always……… start clean cover crops, tillage, herbicides multiple residuals Timely POST’s Post-Harvest “The Greatest American County Agent”
  25. Pre-Plant Burndowns - 2023 BD-01-23 March 30 21 DAT NTC Gramoxone 3SL @ 32 oz/A Aatrex 4L @ 32 oz/A Induce @ 0.25% v/v NTC
  26. Conventional Field Corn Dual, Warrant, Outlook (PRE) Callisto, Laudis, Shieldex, Revulin Q, Steadfast Q (POST) + Atrazine (64 oz/A) + Prowl (32 oz/A) Anthem Maxx, Dual, Warrant, Outlook, Zidua if you don’t like/want/Prowl but……….. adjuvant as needed/required
  27. Field Corn Weed Control - 2023 No Roundup or Liberty?? 1) Warrant 3ME @ 48 oz/A PRE fb 2) HPPD + Aatrex 4L @ 64 oz/A + Prowl H2O 3.8SC @ 32 oz/A + Agridex @ 1% v/v POST (23 DAP) CN-02-23 June 13 52 DAP P2042VYHR Callisto 4SC @ 3 oz/A Laudis 3.5SC @ 3 oz/A Impact 2.8SC @ 1 oz/A Shieldex 3.33SC @ 1 oz/A Revulin Q 51.2DG @ 3.5 oz/A NTC NTC = 233 Bu/A Treated = 257-270 Bu/A
  28. Field Corn Weed Control - 2023 CN-02-23 May 2 17 DAT NTC Callisto 4SC @ 3 oz/A Aatrex 4L @ 64 oz/A Prowl H20 3.8SC @ 32 oz/A Agridex @ 1% v/v POST (24 DAP)
  29. Field Corn Weed Control - 2023 CN-02-23 May 2 17 DAT Laudis 3.5SC @ 3 oz/A Aatrex 4L @ 64 oz/A Prowl H20 3.8SC @ 32 oz/A Agridex @ 1% v/v POST (24 DAP) NTC
  30. Field Corn Weed Control - 2023 No Roundup or Liberty? CN-16-23 May 19 50 DAP D58VC65 NTC Steadfast Q 37.7DG @ 1.5 oz/A Aatrex 4L @ 64 oz/A Prowl H2O 3.8SC @ 32 oz/A Induce @ 0.25% v/v POST (19 DAP) 205 Bu/A 265 Bu/A
  31. RR and/or Liberty Systems
  32. Field Corn Weed Control - 2023 CN-12-23 April 27 15 DAT NTC Roundup P-MAX3 5.88SL @ 22 oz/A Aatrex 4L @ 32 oz/A Prowl H20 3.8SC @ 32 oz/A POST (17 DAP)
  33. Field Corn Weed Control - 2023 CN-15-23 May 30 48 DAT NTC
  34. Field Corn Weed Control - 2023 CN-15-23 May 30 48 DAT NTC
  35. Field Corn Weed Control – 2023 No Roundup or Atrazine CN-01-23 June 13 85 DAP P2042VYHR NTC 202 Bu/A Dual II Magnum 7.64EC @ 16 oz/A (PRE) Liberty 2.34SL @ 32 oz/A Laudis 3.5SC @ 3 oz/A Prowl H20 3.8SC @ 32 oz/A Induce @ 0.25% v/v POST (24 DAP) 242 Bu/A Dual II Magnum 7.64EC @ 16 oz/A (PRE) Liberty 2.34SL @ 32 oz/A Impact 2.8SC @ 1.25 oz/A Prowl H20 3.8SC @ 32 oz/A Induce @ 0.25% v/v POST (24 DAP) 246 Bu/A
  36. Field Corn Weed Control – 2023 No Roundup or Atrazine CN-01-23 June 13 85 DAP P2042VYHR NTC 202 Bu/A Dual II Magnum 7.64EC @ 16 oz/A (PRE) Liberty 2.34SL @ 32 oz/A Shieldex 3.33SC @ 1.35 oz/A Prowl H20 3.8SC @ 32 oz/A Induce @ 0.25% v/v POST (24 DAP) 257 Bu/A Dual II Magnum 7.64EC @ 16 oz/A (PRE) Liberty 2.34SL @ 32 oz/A Callisto 4SC @ 3 oz/A Prowl H20 3.8SC @ 32 oz/A Induce @ 0.25% v/v POST (24 DAP) 254 Bu/A
  37. New(er) Products Being Tested - I Not in UGA Pest Control Handbook (yet?) AMVAC Sinate (glufosinate + topramezone) Impact Core (topramezone + acetochlor) BASF Surtain (encapsulated saflufenacil + pyroxasulfone) Bayer Convintro (diflufenican) TriVolt (isoxaflutole + thiencarbazone + flufenacet) Corteva Kyro (encapsulated acetochlor + topramezone + clopyralid) Resicore (mesotrione + acetochlor + clopyralid) Resicore XL (mesotrione + encapsulated acetochlor + clopyralid) Syngenta Acuron GT (bicyclopyrone + s-metolachlor + mesotrione + glyphosate) Acuron XR (bicyclopyrone + s-metolachlor + mesotrione + atrazine) Storen (s-metolachlor + mesotrione + bicyclopyrone + pyroxasulfone)
  38. New(er) Products Being Tested - II Not in UGA Pest Control Handbook (yet?) Helm Katagon (tolpyralate + nicosulfuron) Helmet Maxx (metolachlor + atrazine + mesotrione) Helena Empyros (tolpyralate + s-metolachlor) Empyros Triad (tolpyralate + s-metolachlor + atrazine) Empyros Triad Flex (tolpyralate + s-metolachlor + atrazine) Valent Maverick (mesotrione + pyroxasulfone + clopyralid) Summit Agro Restraint (tolpyralate + acetochlor + dichlormid)
  39. Field Corn Weed Control - 2023 CN-11-23 August 15 135 DAP NTC Dual II Magnum 7.64E @ 16 oz/A PRE Kyro 3.49ZC @ 45 oz/A Aatrex 4L @ 32 oz/A Roundup PowerMax3 5.88SL @ 26.7 oz/A Prime Oil @ 1% v/v AMSOL @ 2.5% v/v POST (28 DAP)
  40. Field Corn Weed Control - 2023 CN-10-23 August 15 139 DAP NTC Empyros 3.82L @ 45 oz/A Aatrex 4L @ 32 oz/A Grounded @ 16 oz/A PRE No Counter 20G INFR Empyros 3.82L @ 45 oz/A Aatrex 4L @ 32 oz/A Grounded @ 16 oz/A PRE Counter 20G INFR
  41. Field Corn Weed Control – 2023 Late-Season CN-12-23 August 18 150 DAP NTC Storen 3.22ZC @ 57.6 oz/A Aatrex 4L @ 48 oz/A RoundupPowerMax3 5.88SL @ 28 oz/A AMSOL @ 2.5% v/v POST (20 DAP)
  42. Field Corn Weed Control – 2023 CN-11-23 May 26 53 DAP NTC Maverick 2.04SC @ 18 oz/A (PRE) fb Maverick 2.04SC @ 14 oz/A Roundup PowerMax3 5.88SL @ 22 oz/A Induce @ 0.25% v/v AMSOL @ 2.5% v/v (37 DAP)
  43. Post-Harvest
  44. Post-Harvest Weed Control - 2023 Gramoxone 2SL @ 48 oz/A + Tricor 4F @ 8 oz/A + NIS @ 0.25% v/v (15 GPA, AIXR11002 nozzles, 3.5 MPH) September 18 4 DAT sprayed 3 beds/skipped 2 beds (September 14) mowed every other bed (September 5) corn harvested (August 29) TREATED NOT TREATED
  45. Post-Harvest Weed Control - 2023 Gramoxone 2SL @ 48 oz/A + Tricor 4F @ 8 oz/A + NIS @ 0.25% v/v (15 GPA, AIXR11002 nozzles, 3.5 MPH) October 31 47 DAT sprayed 3 beds/skipped 2 beds (September 14) mowed every other bed (September 5) corn harvested (August 29)
  46. Post-Harvest Control of Tropical Spiderwort Untreated 2,4-D @ 1.5 pt/A POST1 + POST 2 POST1: 8-10” tall COMBE POST2: 2 weeks later Photo 1 week after POST2
  47. Questions/Comments