Bulletin 214, Cotton Diseases in Florida


jured bolls, but the wounds caused by insects and the lesions of
other diseases furnish ample means of entry. In some fields in
Florida the Fusarium boll-rot has been found in almost as great
abundance as the previously discussed Diplodia, though ordinarily
it is of much less importance than Diplodia.
 F. moniliforme is also capable of causing a seedling rot and a
root rot. The general importance of these two types of injury is
















 Fig. 10.-Bolls showing different types of Fusarium injury. Bolls infected
 with Fusarium offer no characteristic appearance, as the fungus usually
enters bolls already injured by other causes.

as yet not determined. The fungus can maintain itself in the
soil for indefinite periods of time, and can remain viable in the
seed for several months at least, though infected seed do not
usually germinate.
 The damage to the bolls is the most serious type of injury.
 Bolls attacked by this fungus rot and soon become covered with a
 velvety mass of mycelium and spores, varying from pink to al-
 most white in color. The spores are formed in extremely large
 numbers and serve to further spread the disease. The lint of bolls
 rotted by this fungus becomes stained a pink or yellow color, the
 fibers stick together tightly, and are abundantly covered with the
 fruiting stage of the fungus. Such lint is weak, easily broken, and
 of little value. Probably the greatest injury from the disease
 results from the fungus growing into the lint of partially open
 bolls, or those that have been somewhat injured by other causes.
 Rotting of the lint in the manner described above then follows.