Florida Agricultural Experiment Station


are at the extreme tips of the runners. If the plant is infected
upon the main stem all the tips wilt, but if the infection is on a
single runner some distance from the main stem, the wilting
gradually works back toward the base of the plant and then all
runners are affected and show the wilt, which becomes more
severe each day until the plant is unable to recover and soon dies.
(Fig. 23.)
 Control: It is necessary to control the insects in the field, espe-
cially the striped beetle if present in a field showing wilt. If they
are not present, then the plants showing the symptoms of the
disease should be rogued out and removed from the field. The
disease is transmitted primarily by the injury and inoculation of
plants by biting insects that have fed previously on wilt-diseased
plants.
 BLACK ROT
 This disease, caused by the fungus Mycosphaerella citrullina
 (Sm.) Gross, is found on the fruits, and causes a wilt of the
young seedlings. It also causes a leaf spot, especially on the coty-


Fig. 24. Cotyledons attacked by black rot.