Saturday, November 17, 2012
palmer_pigweed_amaranth

Nebraska: Resistant Palmer Pigweed Migrates Due to Increasing Temperatures

AgFax.Com - Your Online Ag News Source


In early August, Panhandle producers observed a giant pigweed emerging above the corn canopy. With last summer’s extremely high temperatures, Palmer amaranth had made the latest jump in its northward migration.

A troublesome weed in the southern U.S. for many years, Palmer amaranth (Amaranthus palmeri) had been found in Nebraska south of the Platte River and west of Hastings for several years. This year it was also found from the Panhandle to the Sandhills to Antelope County in northeast Nebraska.

It should be of particular concern to Nebraska growers as Palmer amaranth has developed resistance to several major herbicides. It will need to be strategically managed to prevent the further development of resistance.

The Newest Pigweed in Nebraska

Pigweeds, like Palmer amaranth, have been growing in western Nebraska for many years and most growers are familiar with redroot pigweed. In recent years, redroot pigweed has not been as prevalent as in the past due to an increase in common lambsquarters, which emerges earlier in the spring and has more tolerance to glyphosate.

Palmer amaranth is native to the lower Rio Grande Valley of Texas where cotton is an important crop. It was commonly found in the southern United States, and in recent years had expanded its range into Kansas.

Factors Affecting Its Spread

Temperature is the leading ecological factor determining which pigweed species will dominate. Palmer amaranth responds negatively to the low temperatures typical in the northern United States. Its ideal temperature range is between 85°F and 95°F and plant growth declines dramatically between 50°F and 60°F. Growth rate, biomass, and seed production of Palmer amaranth are greater than redroot pigweed at temperatures between 65°F to 95°F.

Palmer amaranth seed is moved via farm equipment, especially combines, or as a contaminant in crop seed or livestock feed. An interesting case in point occurred in 2011 when cottonseed cake used as a protein source for livestock was shipped north. Cotton fields infested with Palmer amaranth were harvested and as seed was removed from cotton fibers, Palmer amaranth seed was mixed in the seed cake. Cattle ate the protein and deposited the Palmer amaranth seed in an environment favorable for expansion.

Palmer amaranth has expanded its range into western and northern Nebraska for several reasons:

  • higher temperatures,
  • reduced use of herbicides at planting,
  • its ability to develop resistance to herbicides, and
  • a decrease in preplant tillage has provided an environment favorable to the weed.

Manage to Reduce Development of Herbicide Resistance

Palmer amaranth growing on your farm may already be resistant to some herbicide families. Triazine-resistant Palmer amaranth has already been identified in Nebraska and UNL researchers are testing for additional resistance development. As is always recommended, avoid relying on a single herbicide mode of action for weed control.

  • Use production practices that do not spread the weed.
  • Rotate herbicide modes of action to reduce the potential for resistance development.

In the south Palmer amaranth has developed resistance to the following herbicide families: dinitroanilines (Prowl, Sonalan), imidazolinones (Pursuit, Raptor), triazines (atrazine), PPO inhibitors (Reflex) and most recently EPSP synthetase inhibition (glyphosate).

Treatment

In the Panhandle, Palmer amaranth has been most noticeable in corn. Corn and weeds such as kochia, common lambsquarters, and hairy nightshade emerge earlier in the spring than Palmer amaranth. Using a herbicide with soil residual such as atrazine, Balance Flexx, Callisto, Dual Magnum, Outlook, Prowl, Permit, Verdict, or Warrant at corn planting will help control early season emergence. Following with a postemergence weed control program with herbicides such as dicamba, 2,4-D, glyphosate, Impact, or Laudis will help control later emerging plants.

In dry bean, herbicides applied at planting such as Dual Magnum, Outlook, Prowl, Sonalan, or Permit can provide early season control while Raptor and Reflex will provide postemergence control.


Tags: , , , ,


Leave a Reply

Name and Email Address are required fields. Your email will not be published or shared with third parties.

Sunbelt Ag News

    Soybeans, Corn in Midwest: Heavy Rain, Early Frost, Slow Going – AgFax9-17

    Farmers First Line of Defense in Keeping GMOs Out of Export Shipments – DTN9-17

    DTN Livestock Close: Cattle Bulls Stage Midweek Recovery9-17

    DTN Cotton Close: Ekes Out Marginal Dec. Gains9-17

    Ohio: 7 Counties Declared Natural Disaster Areas9-17

    DTN Grain Close: Mixed in Another Quiet Day9-17

    AgFax Peanut Review: Record Yields Expected for Virginia; Peanut Butter Salmonella Case Nears Close9-17

    42 California Counties Designated Natural Disaster Areas9-17

    DTN Livestock Midday: Cattle Contracts Holding Strong Gains9-17

    DTN Grain Midday: Corn and Beans Lower, Wheat Mixed9-17

    AgFax Grain Review: Agribusinesses Sue Syngenta; 3 SE Farmers Break Yield Barrier, Set 2 State Records9-17

    Hearing Reflects Highly Politicized Debate Over Biotech Crops — DTN9-17

    DTN Fertilizer Trends: Rabobank Forecasts Higher 3Q Retail Prices9-17

    Cotton in Southwest: Need More Heat; 4-Bale Dryland; Pigweed Plans – AgFax9-17

    DTN Cotton Open: Futures Inch Slightly Higher9-17

    DTN Livestock Open: Cattle Futures Staged for Rally9-17

    China Agrees to Buy $2.3B Worth of U.S. Soybeans — DTN9-17

    DTN Grain Open: All 3 Commodities Start Lower9-17

    Keith Good: 18.3B Bushels of Corn, Soybeans — Where to Put it All?9-17

    Doane Cotton Close: Renewed Selling on Overhead Resistance9-16

    AFB Grain-Soybean Close: Wheat, Soybeans Slide, Corn Posts Modest Gains9-16

    AFB Cotton Close: Dec. Continues Lower9-16

    AFB Rice Close: Down in Narrow Trade9-16

    Missouri Farmer Uses Pig Manure for Natural Gas Production – DTN9-16

    Non-Land Production Costs Unlikely to See Much Decline in 20159-16

    USDA: Weekly National Peanut Prices9-16

    AgFax Cotton Review: Chinese Acreage Declines; Weather Damages Crops in India, Pakistan9-16

    Rice Outlook: U.S. Production Forecast Lowered to 218.3M Cwt9-16

    Georgia Soybeans: Grower Randy Dowdy Breaks The 100-Bushel Barrier9-16

    Insure Your Crop Revenue Guarantee — DTN9-16

    Feed Outlook: Record Corn Crop on Higher Yields9-15

    Corps of Engineers Vindicated in ’11 Missouri River Basin Flood — DTN9-15

    Cotton Outlook: U.S. Production Cut Nearly 1M Bales9-15

    Oil Crops Outlook: U.S. Soybean Yields To Raise Ending Stocks to 8-Year High9-15

    Wheat Outlook: Higher Imports, Decreased Exports9-15

    Good on Grain: Revisions to Corn, Soybean Acreage Estimates Possible9-15

    Choose Your Cover Crops Carefully — DTN9-15

    GMO Critics to Get Their Say at D.C. Hearings — DTN9-15

    Arkansas Forage and Grassland Council Conference Set Oct. 30 in Conway9-15

    Arkansas Winter Forages: What to Plant and How Much9-15

    Flint on Crops: Variety Trials are Worth Your Attention9-15

    Kansas Farmers Can Pursue Prizes for Soybean Yields, Values9-15

    Farmland Auction: Arkansas, Louisiana, Mississippi Cropland – October 229-14

    Rice Crop: Harvest Zooms Along in Texas, Louisiana, Starts to Pick Up in the Delta9-12

    Rice Market: USDA Chops 11.5M CWT from Total Supply9-12

    Rose on Cotton: USDA Released a Bearish S&D Report9-12

    Environmental Groups Sue EPA Over Delay in Chlorpyrifos Ban – DTN9-12

    Cleveland on Cotton: Growers, Do Not Price Your Crop Right Now.9-12

    Welch on Wheat: U.S. and World Ending Stocks Increase9-12

    Welch on Grain: Increased Corn Production, Carryover9-12

    Railroad Criticism a Long-Standing Refrain Among Farmers9-12

    Texas Sorghum: Sugarcane Aphids Confirmed on Southern High Plains9-12

    USDA: Peanut Price Highlights9-12

    AgFax Rice Review: New Reservoir for Texas Growers; Continued Drought Problems in California9-12

    Peanut Harvest Gains Momentum In SE, Starts In Delta – AgFax9-12

    Small Farms and the Affordable Care Act9-12

    Georgia: Plains Peanut Festival, September 27, Celebrates Peanuts And Legacy9-12

    Mississippi Outdoors: Litter is Illegal, Unattractive and Even Harmful9-12

    Farming on the Mother Road: Farmers Becoming Sparse in California — DTN9-12

    Cattle at the Crossroads: Impact of Herd Expansion9-12

    Georgia Gains Section 18 To Apply Transform On Grain Sorghum For Sugarcane Aphids9-12

    U.S. Grain Transportation: Total Inspections Highest Since May9-12

    Nimitz, Non-Fumigant Nematicide, Gains EPA Registration9-12

    Sunbelt Ag Events

     

    About Us

    AgFax.Com covers agricultural trends and production topics, with an emphasis on news about cotton, rice, peanuts, corn, soybeans, wheat and tree crops, including almonds, pecans, walnuts and pistachios.

      

    This site also serves as the on-line presence of electronic crop and pest reports published by AgFax Media LLC (formerly Looking South Communications).

        

    Click here to subscribe to our free reports.

      

    We provide early warnings and confirmations about pests, diseases and other factors that influence yield. Our goal is to quickly provide farmers and crop advisors with information needed to make better and more profitable decisions.

         

    Our free weekly crop and pest advisories include:

    • AgFax Midsouth Cotton, covering cotton production and news in Alabama, Arkansas, Louisiana, Mississippi, Tennessee and Missouri.

    • AgFax Southeast Cotton, covering cotton production and news in Alabama, Florida, Georgia, North Carolina, South Carolina and Virginia.

    • AgFax Southwest Cotton (new for 2013!), covering cotton production and news in Texas, Oklahoma, Kansas and New Mexico.

    • AgFax West (formerly MiteFax: SJV Cotton), covering California cotton, alfalfa, tomatoes and other non-permanent crops in California's Central Valley.

    • AgFax Rice covering rice production and news in Arkansas, Louisiana, Mississippi, Missouri and Texas.

    • AgFax Peanuts, covering peanut production in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Texas and Virginia.

    • AgFax Southern Grain: covering soybeans, corn, milo and small grains in Southern states.

    • AgFax Almonds, covering almonds, pistachios, walnuts and other tree crops in California's Central Valley.

    • AgCom 101, providing guidance to ag professionals involved in social media.

    Our newsletters are sponsored by the following companies: FMC Corporation Chemtura Dow AgroSciences.

          

    Mission statement:

    Make it as easy as possible for our community of readers to find and/or receive needed information.

              

    Contact Information:

    AgFax Media. LLC

    142 Westlake Drive Brandon, MS 39047

    601-992-9488 Office 601-992-3503 Fax

    Owen Taylor Debra L. Ferguson Laurie Courtney

          

    Circulation Questions?

    Contact Laurie Courtney