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2004 Peanut Weed Control Update for Georgia County Agents

Eric P. Prostko
Extension Weed Specialist
University of Georgia

• Slide Presentation (PowerPoint, 6.7 MB)

TABLE OF CONTENTS

Peanut Weed Control Update 2004 Things to Talk About Peanuts - Valor Formulations Valor Formulation Test - 2003 - May 23 (11 DAP) Valor Formulation Test - 2003 - June 11 (30 DAP) Valor Formulation Test - 2003 - July 29 (78 DAP) Peanut yield response to Valor SX (3 ozs/A) applied 1 DAP (2003). Possible Interactions With Valor and Soil Insecticides Peanut Injury in Response to Valor /Insecticide Interactions when applied 5 DAP - Tifton, 2003 Peanut Injury in Response to Valor /Insecticide Interactions when applied 5 DAP - Plains, 2003 Peanuts - Arrow 2EC Texas Panicum Control with POST Grass Herbicides (44 DAT) Peanuts - Prowl H20 3.8CS Prowl H20 Peanut Yield Response to PRE Applications of DNA Herbicides Peanuts - New Metolachlor Formulations Peanuts - Strongarm Postemergence Tropical spiderwort control with POST applied Strongarm, 2003 Bristly Starbur Control with POST Applied Strongarm, 2003 Annual MG Control with POST Applied Strongarm, 2003 Wild poinsettia control with POST herbicides, 2003 Wild Radish Control with POST Applied Strongarm (1", 3-4 leaf) Peanuts: Strongarm Postemergence Summary Bristly Starbur in Peanut Bristly starbur control with POST applications of Strongarm, 2003 Reduced Rates of Strongarm and Valor - I Reduced Rates of Strongarm and Valor - II Economic Returns from Reduced Rates of Strongarm (S), Valor (V), and Cadre - I Economic Returns from Reduced Rates of Strongarm (S), Valor (V), and Cadre - II Summary - Reduced Rates Glyphosate Mishaps in Peanut! Roundup WeatherMax vs. Crop Oil Yield Losses Caused By Roundup Weather Max Applied to Virginia Peanuts @ 30 DAP.

SLIDE CONTENTS

Peanut Weed Control Update2004 Eric P. Prostko Extension Weed Specialist Things to Talk About Valor Arrow Prowl H20 newer metolachlor formulations postemergence Strongarm reduced rates glyphosate problems PeanutsValor Formulations 2001: 51 WDG 2002-03: 51 WP 2004: Valor SX 51WDG * smaller particles * dispersing agents * easier to get into suspension * 10% price reduction in 04’ Valor Formulation Test - 2003May 23 (11 DAP) Untreated Valor SX 3 ozs/A applied 1 DAP Valor Formulation Test - 2003June 11 (30 DAP) Untreated Valor SX 3 ozs/A applied 1 DAP Valor Formulation Test - 2003July 29 (78 DAP) Untreated Valor SX 3 ozs/A applied 1 DAP Peanut yield response to Valor SX (3 ozs/A) applied 1 DAP (2003). PE-02-03 Attapulgus P = 0.80 CV = 12 Possible Interactions With Valor and Soil Insecticides No problems if applied at the right time. If applied late, maybe some problems with Thimet variable Peanut Injury in Response to Valor /Insecticide Interactions when applied 5 DAP - Tifton, 2003 DP-1 Planted May 20, Ratings June 24 b c a b Peanut Injury in Response to Valor /Insecticide Interactions when applied 5 DAP - Plains, 2003 GA Green Planted May 8, Ratings June 11 b bc a bc 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 3.8CS 2004 3.8 lbs/gal 2.0 pts/A water-based micro-encapsulated less staining better for strip-tillage? increased price Prowl H20 pendimethalin EC Prowl H2O Peanut Yield Response to PREApplications of DNA Herbicides PE-11-03 Ponder Farm P = 0.346 2 pts/A 3 pts/A 1.8 pts/A 2.4 pts/A 1.6 pts/A 2.1 pts/A PeanutsNew Metolachlor Formulations Cinch Dupont same as Dual II Magnum cannot use POST 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 PeanutsStrongarm Postemergence labeled in March 2000 PPI, PRE, AC broadleaf weeds 0.45 ozs/A $15-18/A 6% of GA acres in 2001 10 month cotton rotation restriction ALS inhibitor Untreated Strongarm applied 17 DAP Strongarm applied 31 DAP PE-24-03 46 DAP Tropical spiderwort control withPOST applied Strongarm, 2003 Bristly Starbur Control with POSTApplied Strongarm, 2003 PE-27-03 32 DAT Untreated Strongarm @ 0.45 ozs/A Strongarm @ 0.113 ozs/A Untreated Strongarm 0.45 ozs/A + 80/20 @ 0.25% v/v (Applied 5 WAP) 11 WAP Annual MG Control with POST Applied Strongarm, 2003 PE-15-03 67 DAT Wild poinsettia control with POST herbicides, 2003 Untreated Cadre @ 1.44 ozs/A Strongarm @ 0.45 ozs/A Wild Radish Control with POST Applied Strongarm (1”, 3-4 leaf) Untreated Strongarm 0.45 ozs/A Strongarm 0.225 ozs/A 40 DAT PeanutsStrongarm Postemergence Summary good to excellent POST control of several species reduced rates on sensitive species such as bristly starbur, annual morningglory, wild radish timing and rate are critical on some species such as beggarweed no POST control of sicklepod not labeled at this time but working on this issue rotation restrictions????? Bristly Starbur in Peanut 6th most troublesome weed in GA a.k.a. goat-head, Texas sandspur weed-free - 6 weeks interference - 2 weeks 1 plant per meter of row = 14% yield loss Strongarm, Basagran SWSS Weed ID Guide Bristly starbur control with POST applications of Strongarm, 2003 1-15” tall bristly starbur Included 80/20 @ 0.25% v/v Reduced Rates of Strongarm and Valor - I PE-01A-03 91 DAP Untreated Strongarm 0.45 ozs/A Valor 3 ozs/A Strongarm 0.113 ozs/A + Valor 0.75 ozs/A Reduced Rates of Strongarm and Valor - II PE-01B-03 91 DAP Untreated Strongarm 0.45 ozs/A Valor 3 ozs/A Strongarm 0.113 ozs/A + Valor 0.75 ozs/A Economic Returns from Reduced Rates of Strongarm (S), Valor (V), and Cadre - I PE-01A-03 Tifton Economic Returns from Reduced Rates of Strongarm (S), Valor (V), and Cadre - II PE-01B-03 Attapulgus SummaryReduced Rates less injurious than Valor at full rate similar weed control except for tropical spiderwort and annual mg when used in total program (pre + post), equivalent yields and net returns when compared to full rate programs same program in one field may not be the best in another field digging efficiency/weed seed bank concerns in field with a few escapes? Glyphosate Mishaps in Peanut! Roundup WeatherMax vs. Crop Oil Yield Losses Caused By Roundup Weather Max Applied to Virginia Peanuts @ 30 DAP. Source: Adapted from B. Robinson, NCSU (3 years of data)