Bulletin 214, Cotton Diseases in Florida


 Another rather common leaf spot in Florida is known gener-
ally as areolate mildew, and is caused by the fungus Septocylin-
drium areola (Atk.) P. & C. The disease causes little damage,
but because of its conspicuousness should be mentioned. The


 Fig. 15.-A leaf attacked
 by Septocylindrium arcola.
 Note the white color and
 angular shape of the spots.


spots are angular in shape, being limited by the veins of the leaf,
and are white in color, though darkening somewhat with age. The
spots may become as large as one-half inch in diameter, but are
usually considerably smaller. A leaf attacked by this fungus is
shown in Fig. 15.
 A true rust, Kuhneola gossypii Arth., has been reported from
Florida on cotton leaves, but it is rare and of no economic impor-
tance.
 A disease that occurs in Florida, though usually to a small ex-
tent, is the Ascochyta disease of cotton caused by Ascochyta gos-
sypii Sydad. On at least one occasion, however, this disease