In the southwestern U.S., grasses are a severe problem in many cotton growing regions. The introduction of POST graminicides has made a substantial impact on grass weed control in cotton. It is often desirable to apply herbicides in a mixture to broaden the weed control spectrum and to reduce application trips across the field. Studies have been conducted to evaluate the activity of various POST broadleaf and grass herbicides when applied in a mixture. Reduced grass control through antagonism often is a result of applying these combinations.