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2004 Weed Control Update (Peanut, Field Corn, Sunflowers). Dr. Eric P. Prostko Extension Weed Specialist Dept. Crop & Soil Sciences University of Georgia. December 2003. Topic for Discussion. Peanuts Field Corn Sunflowers? Problems questions. Peanuts. Valor Formulations Arrow
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2004 Weed Control Update(Peanut, Field Corn, Sunflowers) Dr. Eric P. Prostko Extension Weed Specialist Dept. Crop & Soil Sciences University of Georgia December 2003
Topic for Discussion • Peanuts • Field Corn • Sunflowers? • Problems • questions
Peanuts • Valor Formulations • Arrow • Prowl H20 • newer metolachlor formulations
PeanutsValor Formulations • 2001: 51 WDG • 2002-03: 51 WP • 2004: Valor SX 51WDG * smaller particles * dispersing agents * easier to get into suspension
Peanut yield response to Valor (3 ozs/A) formulation and timing. PE-02-03 Attapulgus P = 0.80 CV = 12
PeanutsArrow 2EC • clethodim • POST grass control in broadleaf crops • generic Select • Makhteshim-Agan • 6 -16 ozs/A • price/service
Texas Panicum Control with POST Grass Herbicides (44 DAT) PE-19-03 Ponder Farm Applied to 2-4” tall grass
PeanutsProwl H20 • 2004 • 3.8 lbs/gal • 2.0 pts/A • water-based • micro-encapsulated • less staining • better for strip-tillage? • increased price
Peanut Yield Response to PREApplications of DNA Herbicides 2 pts/A 3 pts/A 1.8 pts/A 2.4 pts/A 1.6 pts/A 2.1 pts/A PE-11-03 Ponder Farm P = 0.346
PeanutsNew Metolachlor Formulations • Cinch • Dupont • same as Dual II Magnum • Stalwart C • Sipcam Agro USA Inc. • “old” Dual EC formulation (7.8 lbs/gal) • not labeled for peanut • Me-Too-Lachlor • Drexel • “old Dual EC formulation (8 lbs/gal) • rates are too low
Field Corn • Option vs. Accent • Aim (harvest-aid) • Basis Gold vs. Steadfast ATZ • RR corn issues • Pioneer RR corn hybrids • glyphosate timings
Field CornOption vs. Accent • POST grass control • except crabgrass • OP/SU interaction • roughly same cost/A • similar weed control and yields in UGA tests
Texas Panicum Control in Field Corn- I Accent and Option Applied 24 DAP PANTE = 1”; 2-3LF CN-03-03 Ponder Farm
Texas Panicum Control in Field Corn- IIAccent and Option Applied 24 DAP PANTE = 2”; 2-5 LF CN-04-03 Attapulgus
Corn Yields with Accent and Option a a a ab b c CN-03-03 CN-04-03
Accent vs. OptionAttapulgus - 2003 (19 DAT) Option @ 1.5 ozs/A MSO @ 1.25% v/v AMS @ 3 lbs/A Untreated Accent @ 0.67 ozs/A Agrioil @ 1% v/v Applied 24 DAP/0.25-2” tall PANTE
Field CornAim (Harvest-Aid) • 24C label in GA, MS, LA, NC • up to 1.9 ozs/A • COC @ 1% v/v • 3 day PHI • morningglories • pigweeds • weak on sicklepod
Field CornBasis Gold vs. Steadfast ATZ • 3 way mixes of atrazine/Accent/Matrix • Steadfast has more Accent • Both have greater potential to cause crop injury • confirm hybrid tolerance
Field CornRR Corn Issues • RR Corn 2 (NK 603 event) • Up to 30” tall (over-the-top) • 30-48” tall (drop nozzles) • higher in-crop use rates/A (64 ozs vs 44 ozs RUWM) • Pioneer will have several varieties • Will this change the game?
U.S. Corn Acres Planted to HerbicideResistant Varieties Source: NASS
Sunflowers • Dual Magnum label • IMI-Tolerant sunflowers (Clearfield)
SunflowersDual Magnum • PPI or PRE • 1-1.33 pts/A • coarse soils with 3% or less OM
SunflowersIMI-Tolerant (Clearfield) • Mycogen seed • 8N429CL • non-GMO • Beyond 1AS • imazamox • 4 ozs/A • 2-8 leaf stage • less rotation restrictions than other imi’s • cotton = 9 months
Weed Control in IMI (Clearfield) SunflowersAttapulgus, GA 2003 (60 DAT) Beyond 1AS @ 4 ozs/A AMS @ 3 lbs/A 80/20 @ 0.25% v/v Untreated Prowl 3.3EC @ 2.4 pts/A over entire test.
Problems Worthy of Note in 2003 • misapplications of glyphosate • rain-free periods • FL pusley • unusually unusual weed problems • groundcherry • eclipta • copperleaf
Groundcherry spp. SWSS SWSS
University of Georgia Extension Weed Science (gaweed.com)