Downy mildew of Cucurbits

Downy mildew affects plants of all ages. Although the disease only infects foliage, a reduction in photosynthetic activity early in plant development results in stunted plants and yield reduction, especially in cucumber. Premature defoliation may also result in fruit sunscald due to overexposure to direct sunlight. Symptoms of downy mildew infection exhibit themselves differently on the various cucurbit crops.