NEW AUXIN HERBICIDE TOLERANT COTTON AND SOYBEAN VARIETIES ALLOW FOR THE USE OF 2,4-D AND DICAMBA (AUXIN HERBICIDES) TO BE APPLIED OVER-THE-TOP OF THE CROP, RESULTING IN EFFECTIVE BROADLEAF WEED CONTROL. THESE HERBICIDES REQUIRE THE ADDITION OF A GRASS CONTROL HERBICIDE IN ORDER TO CONTROL GRASSES IN THE FIELD. GROWERS HAVE EXPERIENCED SIGNIFICANT REDUCTION IN GRASS WEED CONTROL WITH THE ADOPTION OF THESE VARIETIES WHICH COMPRISE OVER 80% OF COTTON AND 95% OF SOYBEAN ACRES IN THE SOUTH. THE RESULT OF THE POOR GRASS WEED CONTROL IS DUE TO HERBICIDE ANTAGONISM. HERBICIDE ANTAGONISM IS WHERE ONE HERBICIDE REDUCES THE EFFECTIVENESS OF ANOTHER, REDUCING WEED CONTROL. THIS PROJECT SEEKS TO SCALE UP A PROVEN METHOD OF USING NOVEL METHODS TO APPLY HERBICIDES WHICH RESULT IN OVERCOMING HERBICIDE ANTAGONISM WHEN APPLYING AUXIN HERBICIDES WITH GRASS CONTROL HERBICIDES. OUR RESEARCH AND EXTENSION OBJECTIVES ARE TO 1) FINE-TUNE THE NOVEL APPLICATION METHODS TO OVERCOME HERBICIDE ANTAGONISM 2) ELUCIDATE THE TYPE OF ANTAGONISM OCCURRING WITH THE AUXIN HERBICIDE IN COMBINATION WITH THE GRASS CONTROL HERBICIDE 3) DISSEMINATE THE INFORMATION FOR GROWERS TO CHANGE THE APPLICATION METHOD THEY USE TO APPLY THESE HERBICIDES TO RESULT IN MAXIMUM CONTROL OF GRASS WEEDS IN COTTON AND SOYBEAN. BY USING APPLICATION METHODS TO OVERCOME HERBICIDE ANTAGONISM, THIS PROJECT WILL BE A GAME CHANGER FOR WEED CONTROL ACROSS THE US. THE PROJECT WILL RESULT WILL CREATE A NETWORK OF GROWERS WHO ADOPT THIS TECHNOLOGY CREATING AN ON-GOING AND IMPACTFUL CONTRIBUTION TO IMPROVING WEED CONTROL IN SOUTHERN CROPS.