Field studies were conducted in 1997 and 1998 to evaluate weed control with the tank mixture of Staple and Roundup Ultra in Roundup Ready cotton. The objective of the study was to determine the additive postemergence activity of the two herbicides as well as to determine the benefit of Staple soil residual activity when applied postemergence in a tank mixture with Roundup Ultra. Tests were established throughout the southern cotton region of the United States by both DuPont and University scientists.

Results indicated an increase in pitted morningglory, entireleaf/ivyleaf morningglory, yellow nutsedge, pricky sida, and sicklepod control when Staple at 0.6 ounces product per acre was tank mixed with Roundup Ultra at 1.5 pints per acre as compared to either of the products applied alone. The tank mixture resulted in longer term weed control and a reduction in the number of emerging small seeded broadleaf weeds, as compared to Roundup Ultra alone.