Theses and Dissertations

Issuing Body

Mississippi State University


Reynolds, B. Daniel

Committee Member

Shaw, R. David

Committee Member

Tomaso-Peterson, Maria

Committee Member

Barber, Thomas

Date of Degree


Document Type

Graduate Thesis - Open Access


Weed Science

Degree Name

Master of Science


College of Agriculture and Life Sciences


Department of Plant and Soil Sciences


Due to reduced reproductive tolerance, current Roundup Ready cotton only allows for over-the-top glyphosate applications through the fourth leaf stage of development. To combat this issue, Roundup Ready Flex cotton was introduced in 2006, offering both vegetative and reproductive tissue tolerance to glyphosate. Roundup Ready Flex cotton offers a wider window of application timing, without risk of plant injury. The primary objectives of this research were to test Roundup Ready Flex cotton against current Roundup Ready cotton technology at various application rates and timings and to test various elite varieties of Roundup Ready Flex cotton for glyphosate tolerance. Roundup Ready Flex cotton tolerance was unaffected by application rates or timings. Roundup Ready Flex cotton varieties were unaffected by glyphosate applications. Roundup Ready Flex cotton exhibits both vegetative and reproductive tolerance to glyphosate and is an effective alternative to current Roundup Ready cotton cropping systems.