Farm/Ranch
Talkin' cotton
By NTOK Cotton
Jul 23, 2007
HORSEWEED CONTROL in cotton continues to be a major problem. A weed control project conducted by Oklahoma State University's Extension service last spring is reported on here by Shane Osborne, OSU asst. extension specialist.
"Regardless of the latest and greatest technological advances in the cotton industry, weed problems still plague cotton farmers. Weeds in cotton can rob the soil of both moisture and essential nutrients. Although Roundup Ready Flex cotton varieties (which allow broadcast applications of approved formulations of glyphosate for most of the growing season according to the label) have simplified most producers weed control programs, new problems continue to emerge.
"Horseweed (often referred to as mare's tail) has quickly become one of the biggest weed problems across much of the cotton belt. For the past several years, glyphosate-resistant populations of this weed have grabbed headlines at one time or another in agricultural publications. Even the plants that do not have true resistance to glyphosate (currently the case for most of Oklahoma) can still be very difficult to control.
"Cotton Inc., through the OSU State Support Committee, funded a project held by OSU's Extension Cotton Program this past spring. Two trial locations were chosed, one in Tillman County at the Roger Fischer farm and one at the Doc and Danny Davis farm in Washita County. Both locations were no-till dryland cotton production systems with heavy populations of horseweed.
'"Data from other regions suggested that pre-season control was essential to get a clean start and most programs included either 2,4-D or Banvel. In these tests, four treatments were applied approximately 45 days prior to planting At the Tillman County location, Banvel plus glyphosate plus Valor provided excellent control of horseweed. At the Washita County location,since a cover crop was still growing at application time, glyphosate was dropped out of the mix. However, Banvel plus Valor was again very effective in horseweed control.
"The key to controlling this particular weed is in application timing. Typically, very effective control can be achieved when horseweed is the rosette stage or just beginning to bolt upward. Most successful applications are made on small horseweed less than six inches tall. When there is drought stress, control improves as plant size decreases.
"Detailed information on chemical appplication rates, along with all the treatments evaluated, can be obtained by calling the OSU Southwest Research and Extension Center south of Altus at 1-580-482-2120 or email shane.osborne@okstate.edu. We would like to thank the Cotton Inc. State Support Committee for project funding and Roger Fischer and Doc and Danny Davis for their cooperation."
TALKIN' COTTON is a feature of NTOK Cotton, a cotton industry partnership which encourages increased cotton production in the Rolling Plains of North Texas, Oklahoma and Kansas. For more information on the cotton scene, check out these websites, okiecotton.org. and ntokcotton.org. For comments or questions about Talkin' Cotton, contact us at eventerprise@hughes.net.