downy mildew of watermelon

Downy mildew Figure 1. Chlorotic lesions of downy mildew on a watermelon leaf. Note that a few of the lesions are starting to become necrotic.
Downy mildew Figure 2. Chlorotic and necrotic lesions on watermelon leaf.
Downy mildew Figure 3. Underside of watermelon leaf with downy mildew. Note sporulation of downy mildew-see red arrows.
Downy mildew Figure 4. Severe outbreak of downy mildew on watermelon. Note that stem and fruit of watermelon are not directly affected.