Fungicide resistance in cucurbit powdery mildew : Experiences and challenges

Fungicides are an important tool for managing cucurbit powdery mildew, which is a major production problem in many areas of the world. Unfortunately, these fungicides generally have a high risk of developing resistance because they have specific modes of action, and powdery mildew fungi have a high potential for resistance development. This has been especially true for the predominate cucurbit powdery mildew fungus, Podosphaera (sect. Sphaerotheca) xanthii (Castagne) U. Braun and N. Shishkoff (also known as Sphaerotheca fusca (Fr.) S. Blumer and S. fuliginea.