Anthracnose Symptoms
Anthracnose (fungus - Colletotrichum obiculare): First symptoms
are spots on the foliage that begin as yellowish or watersoaked areas. Spots enlarge
and turn brown to black in color. Diseased tissue dries and the center of the
spots fall out, giving the leaf a "shot-hole" appearance. Symptoms on fruits consist
of circular, black, sunken, cankers varying in size depending on the host plant.
When abundant moisture is present, the center of the spot is surrounded by a gelatinous
pink mass. The fungus overwinters on old cucurbit vines and residues. It may also
be seed-borne. Plants may be infected at any stage of growth. Disease appearance
in the field depends mainly on rainy, cool weather for a period of several days.
All above ground portions may be infected. Seed treatment, crop rotation and destruction
of crop residues are important practices for the control of this disease. Preventative
fungicide applications, as recommended for downy mildew control, should be made
if weather conditions are favorable for disease development. Preventative fungicide
applications will protect plants against infection.
December 20, 1995
