Sclerotinia (White Mold)

Sclerotinia (white mold) Common name Sclerotinia Cottony rot Watery soft rot Stem rot Crown rot Blossom blight Causal agent Sclerotinia is a fungal disease caused by three species of fungi in the genus Sclerotinia. It is more common in cool, wet areas with high humidity. Scientific name Sclerotinia sclerotiorum Sclerotinia minor Sclerotinia trifoliorum Symptoms & Signs White mold is characterized by brown lesions, with white fluffy growth on the infected plants. The fluffy white growth (mycelium) produces hard and black sclerotia. It also shows water-soaked lesions on the stems, fruits, and leaves that enlarge to girdle the stem. As the disease progresses, the leaves wither, wilt, and fall off. This causes the collapse of the entire plant. Transmission The fungal asci produce ascospores that travel via air and water to other plants and infect healthy plants. Periods of heavy rain with cool temperatures between 12-24 °C favor the spread and growth of spores. The spores initially infect the flowers, but the infection gradually spreads to other parts as well. Time of concern Spring to late summer Common hosts Beans Carrots Peas Pumpkins Sunflower Canola Tobacco