Pepper Diseases
Choanephora Blight
Choanephora cucurbitarum
Found in tropical to temperate areas with hot-wet seasons
World Vegetable Center
Symptoms
This fungus is a weak parasite; it colonizes dead or
dying tissue before it actively invades living pepper
tissue. Pepper plants are susceptible from seedling to
early flowering stage. Fruit infection is observed
predominantly around the calyx. Most of the time, it
starts in senescing flower petals. Once established,
entire flowers are overgrown, resulting in a brown to
black mass of soft tissue. Flower stalks, buds, and
leaves may subsequently be invaded.
In the field, the diagnosis is based on the
appearance of a stiff silvery mass of whisker-like or
hairy strands of the fungus growing out of the affected
pepper tissue, topped with a black ball made of great
numbers of spores. This is visible with a hand lens.
Infected young fruit may abort. Individual branches
of a plant may be infected and die back. Individual leaves
on entire plants may wilt. Stems that are infected
appear wet and green and the bark peels off easily in
shreds.
Conditions for Disease Development
The disease usually attacks flowers after they have
fallen and began to decompose; this does not damage
crops. But under extended periods of high rainfall, high
Tip dieback of lateral branches
How to Identify Choanephora Blight
Written by Ray Cerkauskas, Visiting Scientist from Agriculture and Agri-Food Canada. Edited by Tom Kalb. Photos by Glen L. Hartman
and B.H. Chew. Published by AVRDC – The World Vegetable Center; P.O. Box 42, Shanhua; Taiwan 741; ROC
tel: (886-6) 583-7801; fax: (886-6) 583-0009; email: avrdcbox@avrdc.org; www: www.avrdc.org
Silvery whiskers grow out of infected areas, topped
with black spore masses
humidity, and high temperatures (25–30°C), pepper
flowers may remain attached to the young fruits. The
fungus may invade the old flowers and advance into the
fruits. Infection can occur with or without wounding of
host tissue caused by insects or mechanical means.
However, the disease ma