Controlling Palmer Amaranth in Soybean

Transcription

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

2 Prostko s s Picks for Pigweed 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

3 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!

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5 May Rainfall CPES Tifton Inches Year 8/14 years (57%) less than average rainfall!!

6 Soybean Irrigation in Georgia % 20 Acres (%) Year Source: Kerry Harrison, UGA Extension Engineer

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

8 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) FirstShot (7-14 DBP) Sharpen (30 DBP) DBP = days before planting

9 Palmer Amaranth Control with Gramoxone Inteon 2.5 pt/a % v/v 6 hours 4 days AMAPA Height Low = 8 High = 23 Average = 17 7 days 19 days

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

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

12 GR-Pigweed Control in Soybeans SB Macon County 48 DAP NTC Canopy 6 oz/a + Prowl H 2 O 2.1 pt/a (PRE)

13 GR-Palmer Amaranth Control Macon County SB DAP NTC Boundary 1.75 pt/a (PRE) Roundup W-Max 28 oz/a (36 DAP)

14 SB Attapulgus NTC Authority MTZ 12 oz/a PRE (49 DAT)

15 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

16 Metribuzin Crop Rotations Crop Authority MTZ Boundary Canopy Metribuzin 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 n 1% OM.

17 Metribuzin Soybean 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

18 GR-Palmer Amaranth Control in Soybeans with PRE s s (2008) - Macon Co. SB DAT NTC Dual Magnum 1 pt/a

19 GR-Palmer Amaranth Control in Soybeans with PRE s s (2008) - Macon Co. SB DAT NTC Prefix 2 pt/a

20 GR-Palmer Amaranth Control in Soybeans with PRE s s (2008) - Macon Co. SB DAT NTC Envive 3 oz/a

21 GR-Palmer Amaranth Control in Soybeans 2009 (Macon Co.) SB DAP NTC 3 oz/a (PRE) Roundup 22 oz/a (POST)

22 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!!!!!

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

24 Palmer Amaranth Control with Ultra Blazer and Cobra NTC Ultra 1.5 pt/a 0.25% v/v 12.5 oz/a 1% v/v Treatments applied to 2-10 tall pigweed, 6.23 average height Photo 16 DAT

25 PPO Injury

26 Liberty-Link Link Soybeans 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?

27 Liberty-Link Soybeans DAP Ponder Farm NTC Boundary 1.5 pt/a (PRE) Ignite 22 oz/a (19 DAP)

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

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

30 GR-Palmer Amaranth Control with Flexstar GT 65 DAP NTC Flexstar GT 3 pt/a 2.5% v/v Appled 18 DAP

31 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?

32 GR-Palmer Amaranth Control in Soybeans with PRE s s (2008) - Macon Co. SB DAT NTC KIH oz/a

33 DHT Soybeans

34 We are overusing the PPO 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)

35 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!!!!

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

37 Prostko s s Picks for Pigweed 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

38 For More Weed Science Info