Slide Presentation

TITLE    (click title to view slides)
2008 Soybean Weed Control Update

AUTHOR
Eric P. Prostko
Extension Weed Specialist
The University of Georgia

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TABLE OF CONTENTS
  1. 2008 Soybean Weed Control Update
  2. Burndown Options for Reduced Tillage Soybean Production Systems
  3. Conventional Soybean Weed Control - Back to The Future?
  4. U.S. Soybean Acres Planted to Herbicide Resistant Varieties
  5. RR Soybean Weed Control Systems - Things to Think About
  6. Soybean Growth Stages
  7. To Prevent Yield Loss in RR Soybeans
  8. Tolerance of GR-Soybean to Late-Season Glyphosate Applications (1.5 lb ai/A)
  9. Glyphosate + Fungicide Tank-Mixes - Soybean Rust
  10. Glyphosate/Boron/Dimilin - Tank Mixes
  11. Tropical Spiderwort
  12. Tropical Spiderwort in Georgia
  13. Tropical Spiderwort Management in RR Soybeans
  14. Tropical Spiderwort Control in RR Soybeans - Tattnall County - 2005
  15. Conventional Soybean Systems - Tropical Spiderwort Control
  16. Controlling RR Cotton in RR Soybeans
  17. Controlling RR Corn in RR Soybeans
  18. Nutsedge Management in RR Soybeans
  19. Glyphosate/Manganese Tank-Mixes
  20. Glyphosate Resistance Around the World (13 species)
  21. GA Confirmed Glyphosate-Resistant Palmer Sites
  22. GA Confirmed ALS-Resistant Palmer Sites
  23. Soybean Yield Losses Caused by Palmer Amaranth Plants When They Emerge with Crop
  24. Pigweed Control in Soybeans
  25. GR-Pigweed Control without a residual herbicide!
  26. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT)
  27. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT)
  28. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT)
  29. GR-Palmer Amaranth Control in Soybean (2007) (77 DAT)
  30. GR-Palmer Amaranth Control in Soybean (2007) (77 DAT)
  31. This is what a 2' pigweed looks like!!!!
  32. Harmony GT XP or Harmony SG
  33. Harmony GT XP in Soybeans (2007)
  34. Be careful when mixing!! Staple, Envoke, Cadre not a good idea!!!!
  35. www.gaweed.com



SLIDE CONTENTS
  1. 2008 Soybean Weed Control Update Dr. Eric P. Prostko Extension Weed Specialist The University of Georgia
  2. Burndown Options for Reduced Tillage Soybean Production Systems Primary Glyphosate Gramoxone Inteon/Firestorm/Parazone Ignite Tank-mixes 2,4-D (7-15 DBP) Aim (0 DBP) ET (0 DBP) Valor (0 DBP) Harmony Extra (14 DBP) Express (14 DBP) Clarity/Vision (14 DBP + 1” rainfall) Canopy EX (Classic + Express) 7-14 DBP DBP = days before planting
  3. Conventional Soybean Weed Control Back to The Future? Preemergence grasses – Treflan, Prowl, Dual/Generics, Intrro, Micro-Tech, Outlook, Command broadleaf – Boundary, Canopy, Sencor, Pursuit, Scepter, Lorox, Python, Valor, Reflex, Valor XLT many pre-mixes Postemergence grasses – Assure/Targa, Fusilade, Poast, Select/Arrow broadleaf – Ultra Blazer, Basagran, Cobra, Storm, Classic Rotation restrictions
  4. U.S. Soybean Acres Planted to Herbicide Resistant Varieties Source: NASS Source: NASS - Prospective Plantings
  5. RR Soybean Weed Control Systems Things to Think About glyphosate prices are increasing $22/gal (generic 4 lb/gal) current price of RR soybean seed $35/50 lbs (retail) weed resistance issues
  6. V3 stage occurs when 3 trifoliolates are fully developed above the unifoliate leaves R1 stage occurs when one open flower is at any node on the main stem Soybean Growth Stages
  7. To Prevent Yield Loss in RR Soybeans control weeds by 4-5 weeks after planting or control weeds before they reach 6-9” in height or control weeds before the V3 stage Source: Purdue University Extension Weed Science Group (4.32 million acres of RR soybeans planted in 2007)
  8. Tolerance of GR-Soybean to Late-Season Glyphosate Applications (1.5 lb ai/A) J.K. Norsworthy. 2004. Weed Technology 18:454-457 LSD 0.05 = NS
  9. Glyphosate + Fungicide Tank-Mixes Soybean Rust What do labels say? timing concerns Glyphosate = V3 Fungicide = R1 or later limited information preliminary results from UGA research suggest no major problems more data is needed
  10. Glyphosate/Boron/Dimilin Tank Mixes full-bloom to early pod-fill R2-R3 stage Is this the best time for Roundup? (V3) Crop injury? No more than 0.25 to 0.5 lb/A of Boron
  11. Tropical Spiderwort
  12. Tropical Spiderwort in Georgia 2004: 29 counties (light blue) 2005: 5 counties (black) 2006: 6 counties (dark blue) 2007: 2 counties (yellow)
  13. Tropical Spiderwort Management in RR Soybeans timing is critical EPOST Sequence (3 pts/A) Glyphosate + Dual Magnum Extreme (3 pts/A) Glyphosate + Pursuit glyphosate + Pursuit or Classic or FirstRate
  14. Tropical Spiderwort Control in RR Soybeans Tattnall County - 2005 Untreated Sequence @ 3 pts/A Extreme @ 3 pts/A 33 DAT
  15. Conventional Soybean Systems Tropical Spiderwort Control preemergence Dual Magnum (s-metolachlor), Generics Boundary (Sencor + Dual Magnum) Pursuit postemergence Basagran, Classic, Pursuit, FirstRate must be timely! Post-directed/hooded sprayer Gramoxone Max (8’’/3”) or Aim
  16. Controlling RR Cotton in RR Soybeans Preemergence Canopy 75DG (8 oz/A) Sencor 4L (8-12 oz/A) Sencor 75DF (5.3-8 oz/A) POST glyphosate tank-mixes 6” cotton, 3 leaves Resource (4 ozs/A) - 77% 2,4-DB (2 ozs/A) - 76% Reflex (12 ozs/A) - 72% Classic (0.33 ozs/A) - 62% PRE only = 54-87% POST only = 62-77% PRE + POST = > 95% Source: York et al., Weed Technology. 2004. 532-539.
  17. Controlling RR Corn in RR Soybeans tank-mix glyphosate with POST grass herbicide rate depends on height of corn Assure II (5-8 ozs/A) Fusilade (4-8 ozs/A) Select (4-8 ozs/A) Select-Max (8-12 ozs/A) Poast (12-16 ozs/A) Poast Plus (18-24 ozs/A) adjuvants
  18. Nutsedge Management in RR Soybeans split applications of glyphosate better on purple than yellow tank-mix with Classic controls yellow suppresses purple tank-mix with Pursuit better on purple than yellow rotations/cost
  19. Glyphosate/Manganese Tank-Mixes depends upon type of Mn Mn-EDTA (yes) Mn-EAA (no) Mn-LS (no) MnS04 (no) use AMS Mn not a problem with Blazer, Classic, Pursuit, or Basagran. Sources: Bernards et al., 2005 (Weed Technology 19:27-34; Bailey et al., 2002 (Weed Technology 16:792-799); and Heckman et al., 1999 (Journal of Production Agriculture 12:445-448)
  20. Glyphosate Resistance Around the World (13 species) rigid ryegrass (1996) goosegrass (1997) horseweed (2000) Italian ryegrass (2001) hairy fleabane (2003) buckhorn plantain (2003) common ragweed (2004) giant ragweed (2004) Palmer amaranth (2005) common waterhemp (2005) johnsongrass (2005) wild poinsettia (2005) johnsongrass (2005) ** Can be found in the US
  21. GA Confirmed Glyphosate-Resistant Palmer Sites 2005 2006 Current Testing 2007
  22. GA Confirmed ALS-Resistant Palmer Sites
  23. Soybean Yield Losses Caused by Palmer Amaranth Plants When They Emerge with Crop Klingman and Oliver. 1994. Weed Sci. 42:523-527
  24. Pigweed Control in Soybeans use a residual herbicide Valor, Valor XLT, Prefix, Dual Magnum/Generics, Sencor, Boundary, Prowl, Treflan ALS or Glyphosate Resistance!!!! Spray POST herbicides early!!!!!!
  25. Untreated Roundup WM @ 22 oz/A + Cobra 12.5 oz/A (POST) GR-Pigweed Control without a residual herbicide!
  26. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT) Untreated Boundary 6.5EC @ 1.8 pt/A SB-01-07
  27. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT) Untreated Dual Magnum 7.62EC @ 1.33 pt/A SB-01-07
  28. GR-Palmer Amaranth Control in Soybean (2007) (83 DAT) Untreated Prefix 5.2EC @ 2.03 pt/A SB-01-07
  29. GR-Palmer Amaranth Control in Soybean (2007) (77 DAT) Untreated Valor SX 51WG @ 3 oz/A SB-02-07
  30. GR-Palmer Amaranth Control in Soybean (2007) (77 DAT) Untreated Valor XLT 40WG @ 5 oz/A SB-02-07
  31. This is what a 2” pigweed looks like!!!!
  32. Harmony GT XP or Harmony SG Harmony GT XP (75%) GT = grass-tank mix XP = extruded pellet 1/12 oz/A ($1.17) Harmony SG (50%) SG = soluble granules 1/8 oz/A 1st trifoliate until 60 days before harvest tank-mix with glyphosate ALS inhibitor up to 12” tall pigweed????? Soybean injury
  33. Harmony GT XP in Soybeans (2007)
  34. Be careful when mixing!! Staple, Envoke, Cadre not a good idea!!!!
  35. www.gaweed.com