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

    Soybean Harvest: Prioritize Shatter-Prone Fields – DTN10-22

    Ethanol: Court Tosses E15 Labeling Lawsuit – DTN10-22

    AFB Grain-Soybean Close: Wheat Continues Higher, Slight Losses in Corn, Soybeans10-22

    AFB Cotton Close: Inside Day Turns Negative10-22

    AFB Rice Close: Futures Mostly Higher10-22

    Georgia: 2 Counties Declared Natural Disaster Areas10-22

    Arkansas: 2 Counties Designated Natural Disaster Areas10-22

    DTN Cotton Close: Mixed on Light Volume10-22

    DTN Grain Close: Wheat Higher, Corn, Soybeans Pull Back10-22

    AgFax Grain Review: More Lawsuits Against Syngenta; Harvest Well Behind Pace10-22

    DTN Livestock Midday: Hog Futures Lead Complex Higher10-22

    2 Families, 2 Approaches to Building Ranch Tourism — DTN10-22

    DTN Grain Midday: Trade Firm but Off Highs10-22

    Don’t Just Piggy-Back on Others’ Prices in Ag Commodity Markets10-22

    DTN Cotton Open: Higher in Subdued Dealings10-22

    DTN Livestock Open: Trade Off to Sluggish Start10-22

    DTN Grain Open: All 3 Commodities Begin Higher10-22

    National Cotton Council Commends Timely APH Announcement10-22

    Keith Good: APH Yield Exclusion Implementation Draws Praise — Mostly10-22

    Grain TV: Positive News for Soybeans10-21

    DTN Livestock Close: Cattle Futures Move Lower10-21

    Wheat Growers to Seek Inclusion in APH Yield Exclusion for 2015 – DTN10-21

    Doane Cotton Close: Positive Chinese Economy Boosts Prices10-21

    Farm Shop Dream Requires Thoughtful Planning – DTN10-21

    USDA: Weekly National Peanut Prices10-21

    USDA to Implement APH Yield Exclusion for 2015 Spring Crops10-21

    Arkansas: USA Rice Outlook Conference Set Dec. 7-9 in Little Rock10-21

    AgFax Cotton Review: Lower Acres May Close Mill; Australia Acres Up10-21

    DTN Fertilizer Trends: High Costs May Alter Growers’ Tactics for 201510-21

    Herbicide Resistant Weed Summit’s Slides, Webcast Available Online10-20

    Rice and Sugar: Thailand’s Quest for World Domination10-20

    AgFax Peanut Review: NM Down 6M Pounds as State Celebrates 100 Year Crop10-20

    Livestock: WTO Rules Against U.S. in COOL Dispute — DTN10-20

    Wheat Scientists, Breeders Advocate Biotech Crop — DTN10-20

    Good on Grain: Storage Issues May be Less Severe Than Anticipated10-20

    Brazil Soybeans: Planting Falls Further Behind — DTN10-20

    Flint on Crops: Cover Crops Provide Many Benefits10-20

    New Holland Combine Sets Guinness Harvest Record10-18

    Rice Market: Sideways Movement Continues10-17

    Rice Crop: Delta Region Saw Harvest Delays with Storms10-17

    Rose on Cotton: Dec Contract Still Under Pressure10-17

    Cleveland on Cotton: Exports Lowest in ‘My Memory’10-17

    Brazil: Beef Production Steps Up Over Next 10 Years10-17

    Soybeans: Neonic Seed Treatment Little or No Benefit, says EPA – DTN10-17

    Informa Forecast: Soybean Acres Up 4.3M in 2015 – DTN10-17

    DTN Grain Close: Prices Down for the Day, Positive for the Week10-17

    Crop Margins Tighten, Living Expenses Not Far Behind10-17

    USDA: Peanut Price Highlights10-17

    Georgia: 6 Counties Declared Natural Disaster Areas10-17

    Livestock: WTO Ruling on Country of Origin Labeling Expected Soon — DTN10-17

    U.S. Energy: Narrowing Brent-WTI Spread Impacts Global Crude Markets10-17

    Gasoline Prices: Show 9-Cent Decline10-17

    Propane Stocks: Rise by 0.7M Barrels10-17

    Diesel Prices: Average Decreases 4 Cents10-17

    Georgia Blueberries: State Leads Nation in Production — 96M Pounds10-17

    Farm Bill Contingency Plans: How Optimistic are You? – DTN10-16

    Arkansas Agriculture Secretary Calhoun Retiring10-16

    Georgia: Waste Pesticide Disposal, Quitman, Oct. 3010-16

    Global Ag: Ebola Hits West Africa Hard – DTN10-16

    Grain Markets: Crop Prices Up After Bearish USDA Report10-16

    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