ARS | Publication request: CONTRIBUTION OF TILLAGE, RYE COVER CROP AND HERBICIDE PROGRAMS TO WEED CONTROL IN GLYPHOSATE-TOLERANT COTTON

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 27, 2006
Publication Date: June 30, 2006
Citation: Molin, W.T. 2006. CONTRIBUTION OF TILLAGE, RYE COVER CROP AND HERBICIDE PROGRAMS TO WEED CONTROL IN GLYPHOSATE-TOLERANT COTTON. Southern Conservation Tillage Meeting, Amarillo, TX, June 26-28, 2006.

Technical Abstract: The effects of a rye (Secale cereale L.) cover crop, tillage, and glyphosate, applied alone or in combination with preemergence herbicides, were investigated on weed populations in glyphosate-tolerant cotton. The rye cover crop and tillage reduced the populations and occurrence of winter annual weeds with the exception of horseweed (Conyza canadensis) and cutleaf evening primrose (Oenothera laciniata). Weed control provided by the rye cover crop was sufficient to eliminate the use of preemergence herbicides. Glyphosate treatments reduced weed populations to near zero between applications. However, in the time from the last glyphosate application to cotton defoliation, weeds, especially browntop millet (Brachiaria ramose (L.) Stapf), re-grew beneath the cotton canopy and became the most prevalent weed. Browntop millet populations were highest in treatments having the rye cover crop. This added weed pressure could allow more competitive weeds to become established and also complicate mechanical harvest and effect the lint color grade and trash content.