Tuesday, April 24, 2012

Ohio: Early Planting Extends Weed Control Duration

AgFax.Com - Your Online Ag News Source


We have high expectations of herbicide programs, and we have a lot of good herbicides to choose from.  Something that can get overlooked as herbicide programs are planned, however, is the effect of early planting on the duration of weed control that is required.

We plant earlier on average than we did 25 years ago, and then we have years like this one, where we plant even earlier because – we can – or we’re coming off a wet year – or we need to get out of the house – or whatever.  Within the time frame of about mid-April through mid-May, crops planted earlier do not necessarily develop more rapidly, so the time until crop canopy may not vary much with planting date.  Herbicide programs are intended primarily to control weeds until the crop canopy has developed sufficiently to shade out later-emerging weeds.  So the net result of early planting can be an extension of the duration of control that needs to be provided by herbicides.

The further conclusion here is that herbicide programs have to be better now than they were 20 or more years ago to account for early planting, and they have generally evolved to accomplish this through the availability of more effective herbicide combinations and the use of a planned PRE + POST approach.

 

Some things to consider relative to this subject as the season progresses:

#1.  Weeds that can emerge over a broad period of time (or – in weed scientist geek terms – weeds that “exhibit plasticity in germination”) cause the most problems as planting moves earlier.  Summer annual weeds in this category that we commonly deal with in Ohio include giant ragweed, foxtails, shattercane, burcucumber, waterhemp, and also pigweed and morningglory in some years.  These weeds are often most likely to emerge late when an herbicide program that has been applied early in the season loses activity.

#2.  Corn needs to be kept free of weeds until it’s about 20 inches tall through the use of a comprehensive full-rate PRE herbicide program, or the use of a combination of PRE and POST herbicides.  Early planting puts considerable stress on the capability of a total PRE herbicide approach to last long enough, so be sure to scout fields to determine whether a follow up POST program is required.

#3.  In the planned PRE + POST approach for corn, use of a more comprehensive, higher rate PRE herbicide can improve overall effectiveness by controlling weeds more effectively up until the time of the POST, or providing some residual control even after the POST.  Our research shows that the minimum PRE herbicide/rate in this system should be something like 75% of the full use rate of an atrazine premix or similar product.  Rates should be increased and/or a more comprehensive mix of PRE herbicides used for especially early planting or weedier fields.  When the time between planting and crop canopy closure stretches out, there can be considerable value to adding herbicides with residual activity to the POST application.

Examples – the addition of atrazine or Callisto to POST application of glyphosate, Ignite or other non-residual herbicides.  Capreno is a product with that controls emerged weeds and provides residual grass control.  The use of residual POST herbicides is especially important when the corn is relatively small at the time of the POST application, or less than about 12 to 14 inches tall.  This approach can supplement the residual weed control about the time the herbicides applied at planting are losing effectiveness.

#4.  One of our areas of emphasis always is the appropriate management of giant ragweed in soybeans, and early planting makes this more of a concern.  Giant ragweed can emerge well into June, making it difficult to manage with one POST application.  The reality is that moderate to high infestations of giant ragweed, and even fields with patches at this level, are most consistently controlled with two POST applications.  It is possible to obtain adequate control with one POST application, where the PRE herbicides have reduced the size and density of the population considerably.  Where the population has evolved any loss in response to glyphosate, a two-POST approach is more likely to provide control.  We conducted a study in four grower fields last year that showed the value of the two-application POST approach in Roundup Ready soybeans.  A brief report on this research is available on the OSU weed science website here.

This research verified that giant ragweed populations are more effectively reduced when POST herbicides are applied twice, and the first application occurs when plants are no more than about 6 to 10 inches tall.  The approach that many growers use – making a single POST application to larger plants to avoid making a second POST application – results in reduced control and increased survival and seed production.  Early planting makes the two-application POST system even more appropriate, because in a stretched out season, it’s impossible to time one POST application appropriately to ensure that plants are not too large, and the application is late enough to control the plants that are still emerging in June.

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 Midday: Cattle Futures Surge Higher11-21

    A Closer Look at Impacts of Olympic Averaging of Prices and Yields11-21

    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

    DTN Livestock Open: Cattle Futures to Start Mixed11-21

    Changing Weather Brings Challenges to Florida, Iowa Farms — DTN11-21

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

    DTN Grain Open: Lower Start Across Board11-21

    Keith Good: What’s Next for Meat Labeling?; Sugar Prices Take Tumble11-21

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

    Grain TV: Prices Rally on Strong Demand11-20

    DTN Livestock Close: Feeder Futures Pressured by Corn Rally11-20

    Doane Cotton Close: Exports Continue Well Ahead of Pace11-20

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

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

    AFB Grain-Soybean Close: All Markets Bounce Higher11-20

    AFB Cotton Close: Futures See Renewed Pressure11-20

    AFB Rice Close: Prices Continue to Climb11-20

    DTN Grain Close: Exports Boost Prices11-20

    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

    DTN Cotton Close: Gives Back March Gains11-19

    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

    AgFax Rice Review: Iraq Passes on U.S. Rice; Australia, China Sign FTA11-18

    USDA: Weekly National Peanut Prices11-18

    DTN Fertilizer Trends: Prices Show Little Movement11-18

    North Carolina: Bt Resistant Armyworms Migrating North11-18

    Georgia Cotton Commission Meeting, Production Workshop, Tifton, Jan. 2811-18

    Harvest Progress Slows with the End in Sight – DTN11-17

    Brazil Soybean Planting Catches Up – DTN11-17

    Kansas Wheat: Multi-Disease Resistance Subject of New Research11-17

    Good On Grain: Big Gap Between NASS, FSA Should Close Soon11-17

    DTN Midday Grain: Wheat Lifts Soy, Corn Off Today’s Lows11-17

    Farmers Without Working Capital: 6 Steps To Take Immediately – DTN11-17

    Commentary: 60 Minutes Targets California Water Use11-17

    Louisiana Rodeo: ‘Goat Dressing’ is a Tradition11-17

    St. Louis Fed: 3Q Farm Income Down; Farmland Values Up11-17

    Flint on Crops: Everything Begins with the Soil11-17

    Rice Market: Iraq Snubs U.S. Again, Discouraging USDA Reports11-14

    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