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 Prostko’ ’s Picks for Pigweed 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

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 May Rainfall – – CPES Tifton CPES Tifton 1996 1996-

• 2009

2009

1 2 3 4 5 6 7

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Y ear Inches .

8/14 years (57%) less than average rainfall!! 8/14 years (57%) less than average rainfall!!

Soybean Irrigation in Georgia Soybean Irrigation in Georgia

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

23.2% 23.2%

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 7 days 19 days

AMAPA Height Low = 8” High = 23” 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 – Company support – Lack of incentive at dealer level – Cost/A

TriCor 75DF Metribuzin 75DF

GR GR-

• Pigweed Control in Soybeans

Pigweed Control in Soybeans -

• 2008

2008

SB-06-08 Macon County 48 DAP

NTC

Canopy 75DG @ 6 oz/A + Prowl H2O 3.8ASC @ 2.1 pt/A (PRE)

GR GR-

• Palmer Amaranth Control

Palmer Amaranth Control Macon County Macon County -

• 2009

2009

NTC

Boundary 6.5EC @ 1.75 pt/A (PRE) Roundup W-Max 5.5SL @ 28 oz/A (36 DAP)

SB-06-09 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

• n sands, loamy sands, and

sandy loams with less than 1% OM!

• pH
• Varieties
• Rotations

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

• nions

18 months 18 months 18 months 18 months

*not for use on sands, loamy sands, or sandy loams with less tha *not for use on sands, loamy sands, or sandy loams with less than 1% OM. n 1% OM.

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 GR-

• Palmer Amaranth Control in

Palmer Amaranth Control in Soybeans with PRE Soybeans with PRE’ ’s (2008) s (2008) -

• Macon Co.

Macon Co.

NTC Dual Magnum 7.64EC @ 1 pt/A

SB-05-08 48 DAT

GR GR-

• Palmer Amaranth Control in

Palmer Amaranth Control in Soybeans with PRE Soybeans with PRE’ ’s (2008) s (2008) -

• Macon Co.

Macon Co.

NTC Prefix 5.29EC @ 2 pt/A

SB-05-08 48 DAT

GR GR-

• Palmer Amaranth Control in

Palmer Amaranth Control in Soybeans with PRE Soybeans with PRE’ ’s (2008) s (2008) -

• Macon Co.

Macon Co.

NTC Envive 41.3WG @ 3 oz/A

SB-05-08 48 DAT

GR GR-

• Palmer Amaranth Control in Soybeans

Palmer Amaranth Control in Soybeans – – 2009 (Macon Co.) 2009 (Macon Co.)

NTC Valor @ 3 oz/A (PRE) Roundup W-Max @ 22 oz/A (POST)

SB-09-09 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 This is what a 2” ” pigweed looks pigweed looks like!!!! like!!!!

Palmer Amaranth Control with Ultra Blazer and Cobra - 2008

NTC Ultra Blazer @ 1.5 pt/A LI-700 @ 0.25% v/v

Treatments applied to 2-10” tall pigweed , 6.23” average height Photo 16 DAT

Cobra @ 12.5 oz/A Peptoil @ 1% v/v

PPO Injury PPO Injury

Liberty Liberty-

• Link Soybeans

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?

Liberty-Link Soybeans - 2009

NTC Boundary 6.5EC @ 1.5 pt/A (PRE) Ignite 2.34SL @ 22 oz/A (19 DAP)

54 DAP Ponder Farm

Liberty Liberty-

• Link Soybean Variety

Link Soybean Variety Performance Performance – – 2009 2009

(Bu/A +/ (Bu/A +/-

• test average) Test Rank

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) +10.1 (4) +3.3 (9) +3.74 SS LL595N +3.5 (12)

• 6.5

(25) +11.6 (2) +6.1 (7) +3.3 (9) +3.60 Halo 4:65

• 2.8

(25)

• 16.4

(30)

• 17.9

(31)

• 17.3

(32)

• 13.5

(31)

• 13.58

Halo 4:94 +10.6 (1) +8.1 (3)

• 0.8

(19)

• 3.3

(26) +0.4 (17) +3.0 Halo 5:25

• 0.8

(23) +6.4 (5)

• 0.2

(17)

• 0.3

(21) +1.9 (16) +1.4 Halo 5:65 +2.6 (15) +0.6 (14) +7.3 (6)

• 1.0

(22) +6.1 (3) +3.12

Harmony GT XP or Harmony Harmony GT XP or Harmony SG SG

• Harmony GT XP (75%)

– GT = grass-tank mix – XP = extruded pellet – 1/12 oz/A

• Harmony SG (50%)

– SG = soluble granules – 1/8 oz/A

• 1st trifoliate until 60 days before

harvest

• tank-mix with glyphosate
• ALS inhibitor
• up to 12” tall pigweed?????
• variable amounts of soybean

injury

Harmony Harmony -

• YES

YES Harmony Extra Harmony Extra – – NO!!! NO!!!

GR-Palmer Amaranth Control with Flexstar GT – 65 DAP

NTC Flexstar GT 3.31SL @ 3 pt/A 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 GR-

• Palmer Amaranth Control in

Palmer Amaranth Control in Soybeans with PRE Soybeans with PRE’ ’s (2008) s (2008) -

• Macon

Macon Co Co.

.

NTC KIH-485 85WG @ 4.2 oz/A

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 In this 4 year rotation, we could use 16 PPO’ ’s!!!! s!!!!

PPO-Resistant Waterhemp

(Dr. Bryan Young, Southern Illinois Univ.)

Prostko Prostko’ ’s Picks for Pigweed 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

For More Weed Science Info For More Weed Science Info

www.gaweed.com