Bulletin 208, Cucumber Diseases in Florida


 The disease is infectious and will spread from one plant to
 another; further than this very little is known as to the nature of
 the cause. No fungus or bacterial organism has been consistently
 associated with the disease. The disease can be artificially
 produced, however, by rubbing leaves of healthy and diseased
 plants together. In this process there is an exchange of sap of
 the two plants and the sap from the diseased plant has the ability
 to produce the disease in the healthy plant. The symptoms of the
 disease will show up on the inoculated plant after five or six days.
 This process is carried on in nature with the assistance of in-
sects, principally the aphid and common cucumber beetle. The
former is by far the more important in spreading the disease. It
is a sucking insect and after feeding on a diseased plant it may
feed upon a healthy plant, in this way transmitting the disease.
Cultivators and pickers also transmit the disease in the field by
stepping on or brushing first diseased plants and then healthy
plants.
 It has been found that a large number of plants closely related
to the cucumber are susceptible to the disease. There are also a


 Fig. 19. Typical mosaic symptoms on growing cucumber runner, namely
short internodes, small, mottled deeply-notched leaves.