Guide For Tomatoes

T O M AT O E S
White mycelium and
sclerotia are usually
observed in and on
infected fruit.
Disease Cycle
The fungus infects fruit that comes into contact
with infested soil. Fruit lesions appear sunken and
slightly yellow with a ruptured epidermis. Lesions are
water-soaked, soft and often star-shaped. Infected fruit
collapses within three to four days. Brown lesions with
surface mycelium appear on foliage that contacts
infected soil. The fungus can survive for several years
as sclerotia in soil and on host debris. Sclerotia serve
as the primary inoculum. The pathogen may be
disseminated through soil movement by equipment
or by water. Southern blight is a monocyclic disease.
Conditions for Development
Optimum conditions for infection include moist
air and temperatures between 86º to 95º F.
S O U T H E R N B L I G H T
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