Rimsulfuron {N-[[ 4,6-dimethoxy-2-pyrimidinal)amino ]carbonyl]-3-( ethylsulfonyl)-2-pyridinesulfonamide} is a new sulfonylurea herbicide under development by E.I. Dupont de· Nemours & Company Inc. for preemergence and postemergence grass and broadleaf weed control in Solanaceous vegetable crops. The efficacy and selectivity of rimsulfuron were determined in potatoes, transplanted tomatoes, and transplanted peppers in field studies in 1991, 1992, and 1993. Treatments included rimsulfuron and metribuzin alone and in combination in potatoes and tomatoes, rimsulfuron alone in peppers, and sequential applications of rimsulfuron in tomatoes and peppers. Application timings included preemergence and postemergence in potatoes, while only post-transplant applications were evaluated in tomatoes and peppers. Preemergence applications of rimsulfuron controlled weeds if rainfall was received within a few days following application. Control was often greater in potatoes and tomatoes than in peppers. These differences likely relate to more frequent rainfall events in potatoes and tomatoes than in the later-planted peppers. / Master of Science