Current commercial sprayers apply herbicides uniformly across the entire field, even though extensive research has shown that weeds are patchy in distribution and found on less than 40% of the area. There is a commercially available weed-sensing sprayer (WSS) that can discretely detect and treat weeds, but cannot differentiate between weed and crop plants. Therefore, the WSS sprayer can currently be used for weed control only in the area between crop rows. The objectives were to 1) evaluate site-specific weed control and herbicide usage in a site-specific management system to find temporal and spatial relationships within and across years, 2) utilize and modify a decision support system, and 3) develop and disseminate weed biology and management information for producers, extension personnel, and consultants.