U UNIVERSITY of
2006 Florida Plant Disease Management Guide: Eggplant1
Ken Pernezny and Aaron Palmateer2
Specific Common Diseases
Bacterial Wilt (Ralstonia solanacearum)
Symptoms: Plants wilt and die rapidly with slight
or no leaf yellowing prior to death. Plants cut at the
soil line will exhibit brown, slimy pith in
cross-section. Bacterial streaming can be observed
from the vascular tissue when the lower several
inches of stem section are suspended in ajar of water.
Cultural Controls: No economical controls are
available. Avoid land with a previous history of this
disease. Rotate out of susceptible solanaceous crops
into grass, legume or cucurbit crops.
Damping-Off (Fusarium spp., Pythium spp.,
Symptoms: Soil-bore pathogens such as
Fusarium, Pythium and Rhizoctonia species will
infect newly planted seed through the seedling stage.
These pathogens will feed off lateral roots and may
rot the hypocotyl above or below ground causing
Cultural Controls: Plant in well-drained sites
when soil moisture and temperature are conducive to
rapid germination and emergence. Do not plant in soil
with a high percentage of recently incorporated,
undecomposed plant debris. Employ a seed treatment
fungicide and consider soil fumigation of seedbeds.
Chemical Controls: See PPP-6.
Early Blight (Alternaria solani)
Symptoms: Small, light-colored lesions will
occur on leaves, with minimal concentric ringing
characteristics of early blight on potato or tomato.
Very occasionally, leathery spots may be seen on
fruit. The incidence of early blight is often greater in
the presence of mites.
Cultural Controls: Plant as far from tomato and
potato fields as possible.
Chemical Controls: See PPP-6.
1. This document is PDMG-V3-39, one of a series of the Department of Plant Pathology, 2006 Florida Plant Disease Management Guide, Florida Cooperative
Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised December 2005. Please visit the EDIS Web site at
2. Ken Pernezny, professor, Plant Pathology Department, Everglades Research and Education Center, Belle Glade, FL; Aaron Palmateer, assistant professor,
Plant Pathology Department, Tropical Research and Education Center, Homestead, FL; Florida Cooperative Extension Service, Insitute of Food and
Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the
products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and
other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex,
sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service,
University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry
2006 Florida Plant Disease Management Guide: Eggplant 2
Phomopsis Blight (Phomopsis vexans)
Symptoms: Seedlings exhibit dark brown lesions
that become gray in the center and form on the stem
slightly above the soil line. The stem soon becomes
girdled and the plant topples over and dies. On
established plants, brown, round or oval spots may
develop on the leaf and stem becoming irregular in
shape as they enlarge. The center becomes gray and
contains small black dots (pycnidia) while the
margin is a narrow, dark brown zone. Foliar infection
is minor compared to fruit infection. Fruit are infected
while on the plant. The spots are pale, sunken areas
and may finally cover the entire fruit. The small black
pycnidia are present in abundance in the fruit spots.
Cultural Controls: Florida Market and Florida
Beauty are resistant to the "tip over" stage of seedling
blight, but the leaf and stem blight and fruit rot stages
are still serious problems. Maintain a fungicide
program in the transplant bed. Only disease-free
plants should be set into the field.
Chemical Controls: See PPP-6.
Phytophthora Blight (Phytophthora
nicotianae and other Phytophthora spp.)
Symptoms: Severe losses from this disease have
been recorded in southern Florida during wet winter
vegetable seasons. Symptoms include damping-off of
young seedlings, spotting of lower leaves, and decay
at the base of older stems. Advanced stem infection
leads to wilting and collapse of plants. Fruits may
become infected at any time in their development.
Individual fruit spots enlarge rapidly and significant
portions of the fruit may become decayed and soft.
Premature fruit drop often results.
Cultural Controls: Plastic mulch substantially
reduces infection caused by spores of the pathogen
splashed up onto fruit surfaces. Avoid planting
eggplant behind pepper, especially if the pepper crop
has had a confirmed outbreak or a history of
Chemical Controls: Use a pre-plant soil
Pythium Fruit Rot (Pythium spp.)
Symptoms: The blossom end bleaches white, and
then turns tan and wrinkled. The flesh becomes
watery and light brown in color. The white, cottony
mycelium of the pathogen eventually covers the
surface of the fruit-especially during moist periods.
Cultural Controls: Discard all fruits that show
brown discoloration at harvest. The causal agent can
spread by fruit-to-fruit contact and can contaminate
Southern Blight (Sclerotium rolfsii)
Symptoms: This disease occurs during hot, moist
weather. Plants exhibit a progressive wilt with leaf
chlorosis and necrosis beginning with the lower
foliage. The causal fungus infects the root system and
stem at the soil line until the plant is killed. Fruit
borne low on the plant may become infected.
The causal fungus becomes obvious as a coarse
weft of white mycelium on the stem at the soil line
during humid and wet weather. Small
mustard-seed-sized fruiting structures (sclerotia)
form on the mycelium. These are initially white,
maturing to a tan color. These overseasoning
structures fall to the soil and can survive for years
under Florida conditions.
Cultural Controls: No economical control exists
for this disease under Florida conditions. Deep
plowing infested land will reduce disease severity by
burying sclerotia. Crop rotation with a non-host such
as a grass crop is advised.
Verticillium Wilt (Verticillium albo-atrum)
Symptoms: This wilt disease progresses slowly
on eggplant. Plant vigor is affected to the point of
stunting. Lower foliage will exhibit slight yellowing
while plants exhibit progressive daily wilt until death.
Slight vascular discoloration will be evident when
lower stems are slit lengthwise. The degree of
browning is slight compared to bacterial wilt while
the pith is not affected.
Cultural Controls: Do not crop land with a
history of this soilbome fungal disease. Choose
non-susceptible rotation crops such as cucurbits,
2006 Florida Plant Disease Management Guide: Eggplant 3
beans or grasses. The plants of the Solanaceae are
quite susceptible to this fungus.