Slide Presentation

TITLE    (click title to view slides)
2007 Soybean Weed Control Update

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

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TABLE OF CONTENTS
  1. 2007 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. Good News and Bad News: RR Soybean Weed Control Systems
  6. Soybean Growth Stages
  7. To Prevent Yield Loss in RR Soybeans
  8. Glyphosate + Fungicide Tank-Mixes: Soybean Rust
  9. Glyphosate/Boron/Dimilin: Tank Mixes
  10. Tropical Spiderwort
  11. Tropical Spiderwort Management in RR Soybeans
  12. Tropical Spiderwort Control in RR Soybeans: Tattnall County - 2005
  13. Conventional Soybean Systems: Tropical Spiderwort Control
  14. Controlling RR Cotton in RR Soybeans
  15. Controlling RR Corn in RR Soybeans
  16. Nutsedge Management in RR Soybeans
  17. Glyphosate/Manganese Tank-Mixes
  18. Glyphosate Resistance Around the World (12 species)
  19. 2005 GR-Pigweed Survey
  20. Managing Glyphosate Resistant Palmer Amaranth
  21. GR-Pigweed/Soybean Test - 2006: 7 WAP
  22. GR-Pigweed/Soybean Test - III (2006)
  23. UGA Weed Science



SLIDE CONTENTS
  1. 2007 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 Ignite Tank-mixes 2,4-D (7-15 DBP) Aim (0 DBP) Valor (0 DBP) Harmony Extra (45 DBP) Clarity/Vision (14 DBP + 1” rainfall) 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 – Canopy, Canopy XL, Sencor, Pursuit, Scepter, Lorox, Python, Valor 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. Good News and Bad News RR Soybean Weed Control Systems Good News glyphosate getting cheaper and cheaper Bad News higher tech fees/seed costs ($12/50 lb bag) 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 (5.24 million acres of RR soybeans planted in 2006)
  8. 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
  9. 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
  10. Tropical Spiderwort
  11. 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
  12. Tropical Spiderwort Control in RR Soybeans Tattnall County - 2005 Untreated Sequence @ 3 pts/A Extreme @ 3 pts/A 33 DAT
  13. 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
  14. Controlling RR Cotton in RR Soybeans Sencor or Canopy – PRE POST glyphosate tank-mixes Resource (4 ozs/A) Reflex (12 ozs/A) Classic (0.33 ozs/A) need PRE fb POST to be most effective
  15. 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
  16. 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
  17. 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)
  18. Glyphosate Resistance Around the World (12 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) ** Can be found in the US
  19. 2005 GR-Pigweed Survey 47 of 100 sites With Confirmed Resistance to glyphosate!! 1 location in Lee County Confirmed in 2006
  20. Managing Glyphosate Resistant Palmer Amaranth
  21. GR-Pigweed/Soybean Test – 2006 7 WAP Untreated Valor (PRE) fb RUWM (POST) RUWM (POST) Macon County
  22. GR-Pigweed/Soybean Test – III (2006) Untreated Reflex @ 1 pt/A (PRE) Sequence @ 40 oz/A (POST) ($26/A) Macon County - 81 DAP
  23. www.gaweed.com