Sandy Stewart, Chaney, John A. | 4/22/2005 12:32:04 AM
Farmers and industry representatives are learning how the new Roundup Ready Flex cotton can help them control weeds and be competitive in producing a crop.
The reports on Roundup Ready Flex Cotton are among the topics LSU AgCenter experts have covered early this year in a variety of meetings designed to provide cotton producers with research-based information on the latest developments available to them.
Traditionally, Roundup Ready cotton technology allows farmers to control weeds by spraying the herbicide glyphosate over-the-top of the transgenic cotton plants in the efficiently early stages of growth – up to the four-leaf stage. It also allows them to direct the spray underneath the cotton in later stages of growth.
The herbicide controls weeds and lets the resistant cotton flourish in the field with less competition during the early stages of growth.
This year a limited supply of Roundup Ready Flex cotton will be available for farmers to plant. The new Flex system will allow growers to apply higher rates of glyphosate over-the-top – until the 14-leaf stage of cotton growth – which will help control even more difficult weeds.
"Herbicide applications should be timed by weed size and not the size of cotton," said LSU AgCenter cotton specialist Dr. Sandy Stewart, adding, "Roundup Ready Flex technology will allow farmers to control weeds when they need controlling."
This technology should help farmers reduce labor, eliminate some cultivating trips across the field, avoid purchasing additional specialized application equipment and reduce the loss of soil from the field, the experts say.
Research shows that cotton yields are maximized with eight weeks of weed-free growth following germination. In addition, the increased plant resistance of the Flex cotton to glyphosate will allow farmers to use higher rates of the herbicide to control difficult weeds.
LSU AgCenter researchers are testing Roundup Ready Flex cotton technology to assist farmers when they need help.
"We’ve been conducting research on Flex cotton in hopes of answering farmers’ questions when the technology is commercially released," said LSU AgCenter associate professor Donnie Miller.
With selected plantings of Flex cotton occurring this year and commercial release in 2006, researchers will continue testing programs for the control of weeds at different application timings with complimentary herbicides and glyphosate-only programs. They also are checking for the compatibility of glyphosate applied with other spray tank mixes of insecticides, micronutrients and plant growth regulators on some of the more common weeds.
"With all weeds tested, there was no problem with the co-applications," Miller said. "We observed great control and no negative effects when compared to glyphosate applied alone – regardless of weed growth stage."
Last year, about 489,000 cotton acres were planted in Louisiana – most of which were transgenic varieties, Stewart said.
Roundup Flex cotton technology, with its broader application timing and stronger resistance to injury from glyphosate, is another tool for cotton farmers to control difficult weeds emerging from traditional technologies, the experts say.