When the youngest leaves are infected, they may be stippled with dead and yellowish spots. They may even be bunched into a rosette, resembling virus-infected leaves. The growing tips of young plants, especially melons, can be killed. Fruit may be infected at any stage but is most susceptible when young. Gummy plant sap may exude from the spots, especially if the skin is damaged.
Spots become darker with age and collapse to form distinct craters.
Dark green, velvety, fungal growth may appear in the craters under moist conditions. Use disease-free seed. Grow plants in warmer fields, with good air and soil drainage. Avoid overhead watering. Crop rotations of at least 3 years away from all cucurbits is recommended.