Bulletin 229, Diseases of Citrus in Florida


has taken place, in which case they remain on the tree, giving
the attacked twigs and branches much the appearance of having
been scorched by fire (Fig. 37). This is soon followed by the
dropping of the fruit on the affected branches and the dying of
many of the twigs and smaller branches, and even good-sized
branches in severe cases of the disease. Ordinarily, after travel-
ing down the twigs and smaller branches a greater or less dis-
tance, a slight exudation of gum occurs and the disease becomes
self-limited, ending at a sharply defined line which separates the
ain A6:If 7 -1*,


Fig. 37.-Outbreak of withertip on orange tree. The foliage of several
 branches is drying up as though scorched by fire.
diseased from the healthy tissue. After the diseased wood dies
the characteristic, minute black pustules, or fruiting bodies, of
the fungus develop abundantly (Fig. 38).
 Outbreaks of a trouble resembling withertip often develop
during the winter months after the root systems of trees have
been injured by drought or fluctuations of the water table and
run their course within a month or two. The leaves and fruit
may fall from the affected branches but the branches and some
of the twigs often remain green and may develop new leaves