White mold—Sclerotinia sclerotiorum
White mold first appears as a watery rot on stems, leaves, and pods. Under moist conditions,
white mycelium is often visible on the surface of rotted tissue. The development of black, irregularly
shaped sclerotia is the best diagnostic feature. The disease may occur on the stem near the soil
line or on pods, leaves, and stems. Affected tissue may appear bleached.
White mold is favored by a wet soil surface. Use of raised beds and careful furrow irrigation
that does not overflow onto bed surfaces can help limit damage. Space plants well enough to allow
good air circulation. Remove and destroy entire infected plants and crop residues as soon as you
see them. Two years rotation out of susceptible crops (legumes, lettuce, cole crops, cucurbits)
would be required for control of heavy soil infestations. Resistant varieties may be available.
mold on common bean pod
mycelium and bleached stems