Gummy Stem Blight Symptoms
Gummy Stem Blight (fungus - Didymella bryoniae): This fungus infects
leaves and stems, and is more prominent in the crown at soil level. Leaf symptoms
begin with irregular spots that dry and drop out giving the lesion a ragged appearance.
The most conspicuous phase of the disease is the brown exudation in the crown
of infected plants. Vine cankers are found near the soil line, producing a gummy
brown ooze. The fungus overwinters in the soil and on crop residue. The fungus
is seed-borne. Once the fungus becomes established, millions of spores are produced
which can be readily disseminated to other plants by rain, wind or mechanical
equipment. Crop rotation should be practiced. Spraying with fungicides
has also shown to be effective.
December 20, 1995
