Alan
McNab
Professor of Plant Pathology |
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| EGGPLANT
DISEASES |
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Verticillium
Wilt, caused by the fungus Verticillium spp., is a prevalent
and destructive eggplant disease. It causes stunting of plants and
interveinal yellowing, wilting, and rying of leaves. Plants usually
survive in this condition, but a few may die. Woody tissue in the
lower stem is discolored brown. The disease is caused by the same
soil-borne fungus that causes wilt of tomatoes, potatoes, strawberries,
and brambles. The fungus is able to persist in soil for many years.
Presence of root knot or root lesion nematodes may increase disease
severity. |
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Southern
Blight, caused by the fungus Sclerotium rolfsii, is characterized
by softening of crown and external root tissue. Fungus mold and tiny
brown sclerotia (fungus reproductive structures) grow over the base
of the stem and nearby soil. This disease is discussed with pepper
and tomato diseases. |
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Phomopsis
Blight, caused by the fungus Phomopsis vexans, affects all
above-ground plant parts at all stages of development. Spots generally
appear first on seedling stems or leaves. Spots may girdle seedling
stems and kill the seedlings. Leaf spots are clearly defined, circular,
up to about 1 inch in diameter, and brown to gray with a narrow dark
brown margin. In time the center of the spot becomes gray, and black
pycnidia (fungus reproductive structures that appear as small specks)
develop in this area. Affected leaves may turn yellow and die. Fruit
spots are similar to those on leaves but are much larger; affected
fruit are first soft and watery but later may become black and mummified.
Phomopsis persists on and in seed, and overwinters in residue from
diseased plants. It is spread by splashing water. Disease is promoted
by wet weather and high temperatures |
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Anthracnose
Fruit Rot, caused by the fungus Colletotrichum sp., appears
as small spots on ripe fruit. Fruit spots are sunken and, although
variable in size, usually are less than 1/2 inch in diameter. Fruit
with many spots will drop from the plant, leaving the pedicel still
attached. The anthracnose fungus overwinters in soil and in residue
from diseased plants. |
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Alternaria
Blight, caused by the fungus Alternaria solani, occurs on eggplant
as well as tomato. Leaf spots are dark and leathery and range up to
1-3 inch in diameter. When spots are numerous, leaves die prematurely
and drop. Fruit also may be spotted. |
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