Several fungal and oomycete pathogens take their toll on vegetable crops grown in Arizona, causing such diseases as Sclerotinia drop, downy mildew and powdery mildew on lettuce, downy mildew on broccoli and related crops, powdery mildew on melons and other cucurbits, and Phytophthora crown rot on chile peppers.  These diseases are managed by application of fungicides as well as implementation of other disease control tactics. New products are in development that could provide disease control by novel modes of action compared to existing materials. The efficacy of these developmental products is being determined through rigorous field testing, followed by development of application programs that will maximize the level of disease control achieved.