Script

This slideset is to help farmers be able to identify and effectively control Palmer pigweed. It is resistant to glyphosate, so we are having to find alternative methods of control. The following will walk you through the process of Need, Identification, and Control.

Palmer Pigweed

Amaranthus palmeri

History of Palmer Amaranth

• Found in Lauderdale County, TN in 2006• Across West TN in 2008• Couldn’t kill certain Pigweeds in Fulton County

in 2008• Confirmed Resistance in 2009 in Fulton County• Outbreak in 2010• Began Intense Focus in 2011

Enter question text...

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Can You Identify These Pigweeds?

1. Photo 12. Photo 33. Photo 2

1 2 3

Smooth Pigweed Waterhemp

Palmer Amaranth

Palmer Amaranth

Bradley Missouri

Waterhemp Short Flowering Branches

Palmer Long Flowering Branches

Lauderdale County 2008152 oz/A Roundup PowerMax

Steckel 2008

22 fb 22 ozs/A Roundup PM on 1-3” then 6-8” Palmer

Steckel 2009

2 WAA of 40 oz/a of Gly 4

Just Gave Up!

Steckel 2009

Taproot ofA. Palmeri

Allen 2009

Waterhemp Palmer Amaranth Waterhemp &Palmer Amaranth

Waterhemp & Palmer Amaranth Distribution in KY (Co. Agent Survey 2010)

Last Updated 11-23-2010

Waterhemp Palmer Amaranth Waterhemp &Palmer Amaranth

Waterhemp & Palmer Amaranth Distribution in KY (Co. Agent Survey 2011)

Last Updated 12-5-110

Soil-Residual Herbicides For Palmer AmaranthSoil Residual Herbicide Site of Activity P.AmaranthAuthority Assist PPO + ALS ─Authority First / Sonic PPO + ALS XAuthority MTZ PPO + PS II XBoundary PS II + Cell Div . XEnvive PPO +ALS + ALS XGangster PPO + ALS ─Prefix PPO + Cell Div. XSpartan Charge PPO + PPO ─Treflan Microtubule XValor SX PPO XValor XLT PPO & ALS X

Postemergence Soybean Herbicides for Waterhemp & Palmer Amaranth

Post Herbicide

Site of Activity P. Amaranth

Ultra Blazer PPO ─

Cobra PPO ─

Flexstar PPO XFlexstar GT PPO + EPSP X

IgniteGlutamine Synthetase X

KIH 485 (pyroxasulfone)

Initial Discovery & Development

• KUMIAI Chemical Industry Co, Ltd

• IHARA Chemical Industry Co.,Ltd

MARKETING IN US(2012 ?)

• BASF (Zidua)

• FMC (Anthem)

• VALENT (Fierce)

PYROXASULFONE HERBICIDES

HERBICIDE PRODUCT ACTIVE INGREDIENTS

ZIDUA Pyroxasulfone

ANTHEMPyroxasulfone +Fluthiacet (Cadet)

FIERCE Pyroxasulfone +Flumioxazin (Valor)

(For Corn & Soybean 2012?)

EVALUATION OF PREEMERGENCE HERBICIDES FOR PALMER AMARANTH CONTROL (Major’s farm) – 2011)

ANTHEM 8 oz/A

Photo 10-04-11 (Approx 10 WAT)

Fierce 3.75 oz/A

Photo 10-04-11 (Approx 10 WAT)

Zidua 2.5 oz/A

Photo 10-04-11 (Approx 10 WAT)

Preemergence Control of Palmer Amaranth (Fulton Co 2011)

HERBICIDE RATE % ControlAnthem 8 oz/A 100Fierce 3.75 oz/A 100Zidua 2.5 oz/A 98

Applied: 7-27-2011 Rated: 10-04-2011

Preemergence Control of Palmer Amaranth (Fulton Co 2011)

HERBICIDE RATE % ControlAnthem 8 oz/A 100Fierce 3.75 oz/A 100Zidua 2.5 oz/A 98Dual II Magnum 1.67 pt/A 70Warrant 1.7 pt/A 60Boundary 3 pt/A 100

Applied: 7-27-2011 Rated: 10-04-2011

Preemergence Control of Palmer Amaranth (Fulton Co 2011)

HERBICIDE RATE % ControlAnthem 8 oz/A 100Fierce 3.75 oz/A 100Zidua 2.5 oz/A 98Authority First 6.45 oz/A 100Authority MTZ 18 oz/A 98Authority XL 7.5 oz/A 98

Applied: 7-27-2011 Rated: 10-04-2011

Preemergence Control of Palmer Amaranth (Fulton Co 2011)

HERBICIDE RATE % ControlAnthem 8 oz/A 100Fierce 3.75 oz/A 100Zidua 2.5 oz/A 98Prefix 2.75 pt/A 100Spartan 8 OZ/A 100Valor 2.5 oz/A 100

Applied: 7-27-2011 Rated: 10-04-2011

GR Pigweed Summary

• Pre Emergence Options• Boundary (1.5 pts)• Envive (2.5 ozs)• Prefix (1 qts)• Valor (3 ozs)• Authority MTZ (18 ozs)• Valor XLT ( 3 ozs)

GR Pigweed Summary• Post Options:• 1 to 3” Palmer amaranth• Flexstar (1.5 pts)• Cobra (12 ozs)• Blazer (1.5 pts)

Pre Partially Activated and Post a Few Days Late

Steckel 2010

Pre Washed Away and Post a Few Days Late

Steckel 2010

The Difference of 2 Days!

Flexstar on 6” Palmer Flexstar on 3” Palmer

Steckel 2010

What about Ignite?

• Ignite (glufosinate) is a viable alternative• Needs to be applied during middle of the day• Use minimum of 15 gallons of water• New for this year – – Sequential Application– 22-36 oz fb 22-29 oz

29oz Ignite @ 10gal

Same Weed – 3 WAA

Timing is CRITICAL!!!

PPO’s• 1-3 tall Palmer• Multiple applications

may be necessary• Sequential applications

prohibited

Ignite• 1-6 tall Palmer• MUST USE 15gal/Ac!• Try to apply in the

middle of the day• Can use sequential

application

Glyphosate-Resistant Weeds

Conyza canadensis (marestail)Amaranthus palmeri (Palmer amaranth)Ambrosia trifida (giant ragweed)Ambrosia artemisiifolia (common ragweed)Amaranthus tuberculatus (common waterhemp)Lolium multiflorum (Italian ryegrass)Sorghum halepense (Johnsongrass)Eleusine indica (Goosegrass)Poa annua (annual bluegrass)

Southern United States

Questions?

Cam KenimerFulton County Extension Service2114 South 7th

Hickman, KY 42050270-236-2351www.ca.uky.edu/fulton