Bulletin 208, Cucumber Diseases in Florida


on the roots. The vines seldom show lesions, whereas the leaf
petioles and blades are the most severely attacked. The disease on
the fruits is more or less sporadic. Under certain conditions it
causes severe infections and serious losses; whereas in other
instances when the leaves are almost killed the fruit still remains
free from the disease. (Fig. 8.)
 The first symptoms of the disease are slightly yellowish areas
on the leaf blades. This yellow color rapidly spreads in the central



 -












 Fig. 8. The general effect of anthracnose on a cucumber plant.

portion, becomes darker and in a short time turns black. The
spots gradually enlarge in a more or less circular manner. If the
infection is severe these spots coalesce and cause the premature
death of the leaf.
 Anthracnose can be distinguished from other important leaf
spots of cucumber by the more or less circular spots that are not
delimited by the veins. (See Fig. 7.)
 The spores develop on the spots and are readily scattered to
other plants by the many disseminating agents. On the petioles
and stems the lesions are usually sunken and linear in outline.
(See Fig. 9 B.) The tissue is killed and in many instances the
stem is completely girdled and the portion beyond the spot dies.
Spores form on these lesions in a very short time and can be seen
in the form of small groups of pinkish bead-like masses in the
central portion of the lesions.
 On the fruits the infections first appear as more or less circular
or oval water-soaked spots. As the lesion enlarges the central