Downy mildew of Cucurbits
Oomycetes and related to Pythium and Phytophthora. They survive as oospores. From these oospores or surviving mycelium sporangia are formed, structures in which [...] Pseudoperonospora cubensis is a plant pathogen causing downy mildew on cucurbit crops like cucumber, cantaloupe, pumpkin, watermelon and squash. Damage symptoms [...] infect mostly the leaves but occasionally also stems and fruits. They cause lesions on the upper leaf surface, bordered by the veins, which are first yellow