Bell peppers are a staple in many vegetable gardens. Many varieties are disease resistant but most are not. Fungi can cause a number of problems, often killing the plant or spoiling the peppers. Good maintenance practices such as removing volunteer plants and leaf debris from around the base of plants can help prevent infection. The application of a fungicide according to manufacturer's instructions can further protect crops.
White mold is a fungus that grows in the soil known scientifically as Sclerotinia sclerotioru. The fungus overwinters as hard, flattened, black raisin-shaped growths and can survive for years in the soil. It develops in the stems or on the outer surface of the plant as a white mold. It thrives in temperatures around 52 degrees, especially when conditions are damp.
Ripe Fruit Disease
Anthracnose or ripe fruit disease is suspected to come from three different fungi: Colletotrichum: C. capsici, C. coccodes, and C. gloeosporioides. Sunken lesions appear on maturing fruit though at times they can appear on stems, leaves or immature fruit. The lesions can change to black or black with a salmon-colored spore mass in the center. The fungus can live through the winter in the soil and can remain viable for several years.
This fungus is at its worst during moist periods of cool weather. Peppers near the ground, individual leaves and lower parts of the plant nearest the ground are usually affected. The peppers rot until becoming a watery mass. The fungus survives for many years in the soil around the plant area.
Also known as Southern wilt or scientifically as Sclerotium rolfsii, this fungus causes the stems to rot at the soil line and causes the pepper plant leaves to wilt and yellow. White thread-like fibers or mycelium appear on affected areas and develop salmon-colored centers. Damp conditions and warm temperatures are optimal growing environment for this fungus.
Choanephora cucurbitarum is a fungus which affects both mature and immature fruit, leaves, stems and buds. It can cause blossoms to wilt and develop stiff, whisker-like threads with black tips. The fruit will rot on the plant. The fungus , like many of the others, overwinters in the soil and thrives in moist environments.