Whether you are growing pumpkins as a part of an edible garden or if you have annual plans for a pumpkin patch, your cucurbits may display white mold growth as a symptom of a severe problem. White mold disease of pumpkins is distinguishable from other diseases by the black fruiting bodies that grow within the white, cotton-like mold. Caused by the fungus Sclerotinia sclerotiorum, the disease causes your pumpkins to quickly rot once infected. Beginning near the stem and traveling outward, watery areas of fruit collapse as a result of decay.
Recognize that once white mold has infected your pumpkin plant, though you can physically scrape away the white mold growth, these plants are beyond saving. Aim for the goal of saving your remaining pumpkins and eradicating this disease from your gardening space.
Use drip irrigation instead of overhead irrigation as the standing moisture on pumpkin plants encourages fungal growth of white mold. Irrigate only during dry periods as pumpkins tolerate hot temperatures and arid climates, but wet conditions increase the likelihood of infection.
Avoid wounding pumpkins as these openings act as entry points for fungal pathogens.
Remove and destroy pumpkins infected with white mold. Avoid planting other highly susceptible plants like cabbage or beans, which can promote spreading or re-introduce fungal disease to your pumpkins.
Rotate your pumpkin crops to corn or grass in order to move pumpkins out of potentially infested soil unless only a few pumpkins are infected and removed.
Ensure that pumpkins are planted with sufficient space between plants in rows spaced 10 to 15 feet apart as open growth decreases the likelihood of infection.