Monday, October 14, 2013
marestail

Nebraska: Managing Winter Annual Weeds Starts in Fall

AgFax.Com - Your Online Ag News Source


While corn and soybean harvest may be your primary concern this month, look for opportunities to scout from the combine and prepare for effective winter annual weed management in 2014.

With recent rains and cooling temperatures, winter annual weeds are emerging and actively growing in row crops across Nebraska. Scouting during harvest can give no-till producers a head start on weed control in 2014.

 

Winter Annual Weeds

Winter annual weeds have become prolific in many Nebraska no-till fields. This increase has been associated with:

  • increased adoption of conservation tillage practices,
  • widespread adoption of glyphosate-resistant crops and the subsequent increased reliance on total postemergence weed control programs, and
  • the reduced use of soil residual herbicides in corn and soybean production.

The impact of winter annual weeds in cropping systems is sometimes overlooked because these weeds typically complete most of their lifecycle prior to or shortly after corn and soybean planting. However, dense mats of winter annual weeds may result in delayed soil warming in spring, direct and indirect competition for water and nutrients during initial establishment of the summer crop, and difficulties at planting. Moreover, winter annual weed species can act as alternative hosts for pests. For example, henbit is known to be an alternative host for soybean cyst nematode (SCN), a major soybean pathogen.

Recent research on emergence timing of winter annual weeds across Nebraska showed that downy brome, tansymustard, henbit, Carolina foxtail, and field pansy emerged mostly in the fall (more than 90% of total emergence). Virginia pepperweed and purslane speedwell had the majority of the seedlings emerging in the fall (approximately 70% of total emergence), but some seedlings also emerged during late winter and early spring. Shepherdspurse and field pennycress had some seedlings emerging during fall (approximately 30% of total emergence), but the majority of it occured in late winter and early spring.

If in previous years farmers have noticed fields infested with fall-emerging species such as marestail, henbit, downy brome, tansymustard, Carolina foxtail, field pansy, Virginia pepperweed, and purslane speedwell, these fields should be scouted and perhaps managed after crop harvest in the fall. Scouting and management of fields infested with mostly spring-emerging species such as shepherdspurse and field pennycress is more appropriate in spring.

Marestail is a troublesome weed in Nebraska no-till fields and glyphosate-resistant populations are prevalent throughout much of the state. Research has shown that marestail tends to germinate mostly in the fall in Nebraska, however in other areas of the Corn Belt it germinates through the spring and summer. According to our observations and conversations with growers, henbit and marestail seem to be the most prevalent winter annual weeds in much of eastern Nebraska. As these species are expected to emerge mostly in the fall, scouting and managing these fields right after crop harvest is a reasonable strategy.

Key Considerations

  • Numerous herbicide tank-mix options are available for control of most winter annual weeds. Consult pages 59 (corn) and 103 (soybeans) of the 2013 Guide for Weed Management in Nebraska (EC130) for effective options for your winter annual weed spectrum.
  • In the Nebraska research cited previously, the majority of fall emergence was completed by early November, thus, targeting herbicide applications from late October to mid November would be prudent. Younger weeds tend to be more susceptible to herbicide treatments in the fall or early spring when they are small. Waiting until late spring may not result in the desired control if these weeds are at an advanced growth stage.
  • If glyphosate-resistant marestail is one of the primary targets of control, the use or inclusion of a growth regulator herbicide (2,4-D and/or dicamba) is necessary for adequate control. We believe that 2013 was a relatively light year for marestail, in part due to extreme drought conditions during the fall 2012 germination period. With recent precipitation, marestail is germinating and could become more of a problem in 2014 if timely management is ignored.
  • Field pansy has become more prevalent in southern Nebraska in recent years. In our trials, 2,4-D and dicamba have been relatively ineffective on this species. Products that contain chlorimuron (e.g., Classic, Authority XL, Valor XLT) have shown good results with fall applications. Applying a product with chloriumuron in the fall will require rotation to soybeans the following year.

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

    DTN Livestock Open: Cattle Futures Geared for Higher Start11-24

    Flint on Crops: Low Input Farming May be Necessary in 201511-24

    DTN Grain Open: Markets Begin Week Lower11-24

    Keith Good: EPA Decision on Renewable Fuels Mandate Delayed to 201511-24

    Midwest Corn And Soybean Yields – Our Readers’ Reports – AgFax11-22

    Rice Comment: The Case for Neonicotinoid Seed Treatment11-22

    U.S. Rice: Rain Stalls Texas 2nd Crop Harvest; Crop Sales Continue11-22

    Rice Market: Sale to Iraq Moves the Market11-22

    Rose on Cotton: Looking for the Positives This Week11-21

    Grain Drying: 6 Questions About Effects Of Sudden Drop In Temps11-21

    Is Your Lifestyle Costing You the Farm?11-21

    DTN Livestock Close: Cattle Futures Solidly Higher11-21

    Farmers Storing Grain Need to Weigh Risk Management Factors – DTN11-21

    Peanut Harvest Updates From Southeast, Delta And Southwest – AgFax11-21

    Cleveland on Cotton: 57 Cents – ‘The Bottom is In’11-21

    Ag Labor: Immigration Order Provides Little Long-Term Benefit – DTN11-21

    Doane Cotton Close: Decline in Chinese Production Offers Support11-21

    AFB Grain-Soybean Close: Strong Soybean Gains, Little Movement in Corn, Wheat11-21

    Southern Soybean, Corn Harvest Reports, Round One – AgFax11-21

    AFB Cotton Close: Futures Rebound11-21

    AFB Rice Close: Prices See More Slight Gains11-21

    DTN Cotton Close: Settles Higher on Light Volume11-21

    DTN Grain Close: Soybeans Boosted by Demand11-21

    USDA: Peanut Price Highlights11-21

    Oklahoma Pecans: Deliveries Remain Light11-21

    Georgia Pecans: Buying Interest Very Active11-21

    Ag Policy: Farm Bills Need Long-Term View11-21

    Cotton Market Weekly Review by Region11-21

    DTN Livestock Midday: Cattle Futures Surge Higher11-21

    Arkansas Cattle: Ranchers Should be Alert to Acorn Poisoning11-21

    DTN Grain Midday: All 3 Commodities Go Higher11-21

    Economist: Livestock Industry Will Have Strong Rebound11-21

    DTN Dried Distillers Grain: Cheaper Feed Source for Beef Producers?11-21

    Mississippi Outdoors: Common Deer Parasites Do Not Affect Venison11-21

    DTN Cotton Open: Trades Higher after No Notices Issued11-21

    AgFax Wildlife Review: New E-Book Offers Tips for Gardening in South11-21

    Weather Challenges Florida and Iowa Farms — DTN11-21

    Vilsack: Immigration Order Creates ‘Stability’ in Ag Work Force — DTN11-21

    Texas Cotton Harvest – Still Some To Go – AgFax11-20

    Mississippi: Water Conservation Summit, Stoneville, Dec. 1011-20

    Farm Internet Service Still Slow or Non-Existent, But Improving – DTN11-20

    Yield: Important Factor in Your Irrevocable Farm Program Choice11-20

    U.S. Grain Transportation: Weekly Inspections Reach Record11-20

    U.S. Drought Outlook: Improvements Expected for California, Southwest11-20

    U.S. Energy: Planned Refinery Maintenance Light in 201411-20

    Propane Stocks: Post Slight Increase11-20

    Gasoline Prices: Decrease by 5 Cents11-20

    Diesel Prices: Average Drops 2 Cents11-20

    Livestock: Arctic Chill Catches Markets Flatfooted – DTN11-19

    Farm Runoff Targeted for Regulation Following Algal Bloom Shutdown – DTN11-19

    Soybeans: China May Import More Non-GMO Beans – DTN11-19

    Mississippi Outdoors: Free Apps Can Aid Deer Hunters11-19

    Big River Rice And Grain Enhances, Expands Facilities In Arkansas, Louisiana11-19

    Farm Bill Commodity Program: Decisions and More Decisions11-18

    Young Farmers: USDA is the ‘Lender of 1st Opportunity’ – DTN11-18

    Tax Extenders: Farm Groups Push Congress to Renew Section 179 This Year – DTN11-18

    USDA: Weekly National Peanut Prices11-18

    DTN Fertilizer Trends: Prices Show Little Movement11-18

    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