Bulletin 208, Cucumber Diseases in Florida


up to the present time in Florida except in small late summer
garden patches.
 The fungus lives from one season to the next on wild host plants
and on old leaves and vines that have not been destroyed. The
spores are scattered by the wind and rain and germinate quickly
in water from rain or heavy dew.
 Description: The first noticeable evidence of macrosporium
blight on the cucumber is a small brownish spot. These spots
enlarge and become dark brown, showing concentric zoning as
they develop, often enlarging to almost a centimeter in diameter.
At this time the brown, dried central portions often crack and
fall away, leaving holes in the leaves. When there are numerous
spots on the leaves they coalesce and quickly kill the whole leaf.
The disease has not been observed on the stems but has caused
some infections on the fruits, especially those sunburned or
otherwise injured. It has not been important, however, on the
fruits.


 Fig. 29. Albino cucumber fruits probably the result from reversion to
white spine types.