Controlling Controlling Palmer Palmer Amaranth in Amaranth in - PowerPoint PPT Presentation

Controlling Controlling Palmer Palmer Amaranth in Amaranth in Soybean Soybean Eric P. Prostko Associate Professor and Extension Weed Specialist Department of Crop & Soil Sciences The University of Georgia

Prostko’ ’s Picks for Pigweed s Picks for Pigweed Prostko • Know your enemy! • Drill a well! • Start Clean! • Use a residual! • POST treatments when 3” tall or less • Remove escapes before seed production • Think About the Future – Overuse of PPO’s

Palmer Amaranth Facts Palmer Amaranth Facts ( Amaranthus palmeri ) • grows faster than other pigweeds (1-2” per day!!) • more competitive than other pigweeds – 1 plant/row meter = 33% soybean yield loss • prolific seed producer – 400,000+/plant • Most emerges from 1” or less! • Pollen can move at least 900’! • Seed do not last very long in soil!

May Rainfall – – CPES Tifton CPES Tifton May Rainfall 1996- -2009 2009 1996 7 6 Inches . 5 4 3 2 1 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Y ear 8/14 years (57%) less than average rainfall!! 8/14 years (57%) less than average rainfall!!

Soybean Irrigation in Georgia Soybean Irrigation in Georgia 25 23.2% 23.2% 20 cres (%) 15 A 10 5 0 1970 1975 1977 1980 1986 1992 1995 2000 2004 2008 Y ear Source: Kerry Harrison, UGA Extension Engineer

Start Clean!!!!!! Start Clean!!!!!! Tillage/Cover Crops/ Herbicides Tillage/Cover Crops/ Herbicides

Burndown Options for Reduced Burndown Options for Reduced Tillage Soybean Production Tillage Soybean Production Systems 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) – FirstShot (7-14 DBP) – Sharpen (30 DBP) DBP = days before planting

Palmer Amaranth Control with Gramoxone Inteon 2SL @ 2.5 pt/A + 80/20 @ 0.25% v/v 6 hours 4 days AMAPA Height Low = 8” 19 days High = 23” 7 days Average = 17”

Residual Herbicides Residual Herbicides • Treflan, Prowl • Dual, Intrro (Lasso) • Pursuit, Scepter • Metribuzin Products** – Authority MTZ, Boundary, Canopy, Sencor/Metri • Valor, Valor XLT, Reflex, Envive, Prefix

Why metribuzin on soybean? Why metribuzin on soybean? • Not a PPO • Good on pigweed • Can be applied PPI • Issues – soil texture, OM, pH – Varieties – Rotations TriCor 75DF – Company support Metribuzin 75DF – Lack of incentive at dealer level – Cost/A

GR- -Pigweed Control in Soybeans Pigweed Control in Soybeans - - 2008 2008 GR Canopy 75DG @ 6 oz/A + NTC SB-06-08 Prowl H 2 O 3.8ASC @ 2.1 pt/A (PRE) Macon County 48 DAP

GR- -Palmer Amaranth Control Palmer Amaranth Control GR Macon County - - 2009 2009 Macon County NTC Boundary 6.5EC @ 1.75 pt/A (PRE) SB-06-09 Roundup W-Max 5.5SL @ 28 oz/A (36 DAP) 65 DAP

NTC Authority MTZ 45DG @ 12 oz/A PRE (49 DAT) SB SB- -12 12- -09 09 Attapulgus Attapulgus

Metribuzin Headaches Metribuzin Headaches • Soil texture, OM – Metribuzin should not be used on sands, loamy sands, and sandy loams with less than 1% OM! • pH • Varieties • Rotations

Metribuzin Crop Rotations Crop Authority Metribuzin MTZ Boundary Canopy TriCor Field corn 4 months 8 months 10 months 4 months wheat 4 months 4.5 months 4 months 4 months cotton 12 months 8 months 10 months 18 months peanut 12 months 12 months 18 months 18 months sorghum 12 months 12 months 12 months 18 months onions 18 months 18 months 18 months 18 months *not for use on sands, loamy sands, or sandy loams with less than 1% OM. n 1% OM. *not for use on sands, loamy sands, or sandy loams with less tha

Metribuzin Soybean Metribuzin Soybean Tolerance Tolerance • Group IV: Asgrow 4903 RR/STS, Southern States RT4808 • Group V: Asgrow 5905RR , AGS 568RR , Delta Pineland DP5634, Pioneer 95Y20 , Pioneer 95Y40, Pioneer 95Y70 , Southern States RT5951NRR • Group VI: Asgrow 6301RR , Delta Pineland DP6568, Pioneer 96M60, Southern States RT 6451NRR , Vigoro V61N9 • Group VII: AGS 758RR, Asgrow H7242, Benning , Dekalb H7242, Northrup King NKS 76L9, Northrup King NKS 78G6, Pioneer 97M50 , USG 7732nRR, Vigoro V74N9, Woodruff • Group VIII : Northrup King NKS 80P2, Prichard RR

GR- -Palmer Amaranth Control in Palmer Amaranth Control in GR Soybeans with PRE’ ’s (2008) s (2008) - - Macon Co. Macon Co. Soybeans with PRE Dual Magnum 7.64EC @ 1 pt/A NTC SB-05-08 48 DAT

GR- -Palmer Amaranth Control in Palmer Amaranth Control in GR Soybeans with PRE’ ’s (2008) s (2008) - - Macon Co. Macon Co. Soybeans with PRE Prefix 5.29EC @ 2 pt/A NTC SB-05-08 48 DAT

GR- -Palmer Amaranth Control in Palmer Amaranth Control in GR Soybeans with PRE’ ’s (2008) s (2008) - - Macon Co. Macon Co. Soybeans with PRE Envive 41.3WG @ 3 oz/A NTC SB-05-08 48 DAT

GR- -Palmer Amaranth Control in Soybeans Palmer Amaranth Control in Soybeans – – GR 2009 (Macon Co.) 2009 (Macon Co.) Valor @ 3 oz/A (PRE) NTC SB-09-09 Roundup W-Max @ 22 oz/A (POST) 46 DAP

Postemergence Postemergence • PPO’s – Ultra Blazer, Cobra, Storm, ET, Aim, Reflex, Prefix, Flexstar GT (RR), Cadet • ALS – Harmony SG, Pursuit • Other – Ignite (LL) • Must be applied before 3”!!!!!

This is what a 2” ” pigweed looks pigweed looks This is what a 2 like!!!! like!!!!

Palmer Amaranth Control with Ultra Blazer and Cobra - 2008 Cobra @ 12.5 oz/A Ultra Blazer @ 1.5 pt/A NTC Peptoil @ 1% v/v LI-700 @ 0.25% v/v Treatments applied to 2-10” tall pigweed , 6.23” average height Photo 16 DAT

PPO Injury PPO Injury

Liberty- -Link Soybeans Link Soybeans Liberty • Not necessarily a direct replacement for Roundup! • Use a residual herbicide in this system!!!!!!! • Not usually good on pigweed bigger than 3” • Tank-mixes with POST grass herbicides may reduce grass control – Assure (10-21%); Fusilade (8- 12%); Poast (25-41%); Select 4- 22%) • Variety performance?

Liberty-Link Soybeans - 2009 Boundary 6.5EC @ 1.5 pt/A (PRE) NTC Ignite 2.34SL @ 22 oz/A (19 DAP) 54 DAP Ponder Farm

Liberty- -Link Soybean Variety Link Soybean Variety Liberty Performance – Performance – 2009 2009 (Bu/A +/- - test average) Test Rank test average) Test Rank (Bu/A +/ Variety Athens Calhoun Griffin Midville Tifton (May 15) (May 21) (May 15) (June 10) (June 1) Average SS -1.9 +4.6 +2.6 +10.1 +3.3 +3.74 LL511N (24) (11) (9) (7) (4) SS +3.5 -6.5 +11.6 +6.1 +3.3 +3.60 LL595N (12) (2) (25) (7) (9) Halo -2.8 -16.4 -17.9 -17.3 -13.5 -13.58 4:65 (25) (31) (32) (31) (30) Halo +10.6 +8.1 -0.8 -3.3 +0.4 +3.0 4:94 (1) (19) (17) (3) (26) Halo -0.8 +6.4 -0.2 -0.3 +1.9 +1.4 5:25 (23) (17) (16) (5) (21) Halo +2.6 +0.6 +7.3 -1.0 +6.1 +3.12 5:65 (6) (3) (15) (14) (22)

Harmony GT XP or Harmony Harmony GT XP or Harmony SG SG • Harmony GT XP (75%) Harmony - - YES YES Harmony – GT = grass-tank mix – XP = extruded pellet – 1/12 oz/A • Harmony SG (50%) – SG = soluble granules – 1/8 oz/A Harmony Extra – – NO!!! NO!!! Harmony Extra 1 st trifoliate until 60 days before • harvest • tank-mix with glyphosate • ALS inhibitor • up to 12” tall pigweed????? • variable amounts of soybean injury

GR-Palmer Amaranth Control with Flexstar GT – 65 DAP Flexstar GT 3.31SL @ 3 pt/A NTC AMS @ 2.5% v/v Appled 18 DAP

On the Horizon On the Horizon • KIH-485 • DHT Soybean – DowAgroScience Herbicide Tolerance – Enhanced tolerance to 2,4-D – Stacked with glyphosate – 2013? • GAT Soybean – Glyphosate ALS Tolerance – DuPont – 2011? • Dicamba Resistant Soybeans – Monsanto/BASF – Stacked with glyphosate – 2013?

GR- -Palmer Amaranth Control in Palmer Amaranth Control in GR Soybeans with PRE’ ’s (2008) s (2008) - - Macon Macon Soybeans with PRE Co . Co . KIH-485 85WG @ 4.2 oz/A NTC SB-05-08 48 DAT

DHT Soybeans DHT Soybeans

We are overusing the PPO We are overusing the PPO inhibiting herbicides!!!!!!!! inhibiting herbicides!!!!!!!! • Resistance has already been reported in other areas!!! • Common waterhemp – 2001 (Kansas) – 2002 (Illinois) – 2003 (Missouri) • Common ragweed – 2005 (Delaware) • Wild poinsettia – 2004 (Brazil)

Could this happen in SE? Could this happen in SE? Crop PPLNT PRE POST/PDIR Harvest Aid Soybean Valor Reflex Cobra Aim Cotton Valor Reflex Valor Aim/ET Corn Valor Sharpen Aim Aim Peanut Aim/ET Valor Ultra Blazer Aim In this 4 year rotation, we could use 16 PPO’ ’s!!!! s!!!! In this 4 year rotation, we could use 16 PPO

PPO-Resistant Waterhemp ( Dr. Bryan Young, Southern Illinois Univ.)

Prostko’ ’s Picks for Pigweed s Picks for Pigweed Prostko • Know your enemy! • Drill a well! • Start Clean! • Use a residual! • POST treatments when 3” tall or less • Remove escapes before seed production • Think About the Future – Overuse of PPO’s