42 
FLORIDA STATE HORTICULTURAL SOCIETY 
move all dead twigs and branches and 
any sickly or weakened growth. Large 
patches of dead bark or inner branches 
should also be removed as far as it is 
possible to do so. This rubbish should 
be removed from the groves and burned 
as it may prove a source of future infec¬ 
tion if allowed to remain under the trees. 
In many cases a thorough application of 
Bordeaux Mixture would be advisable, 
following the pruning especially where 
trees have set fruit. This should be made 
as a clean-up spray and the inner branches 
should be well covered with the fungicide 
as well as the foliage. 
In extreme cases further spraying may 
be necessary. Trees that have been badly 
injured may contain many small patches 
of dead bark on the inner branches which 
are filled with the fungus and these may 
become active centers in spreading the 
disease. Such patches may not be easily 
detected and they will be difficult to handle 
under the most favorable circumstances. 
If the inner branches of such trees can be 
kept covered with a fungicide during the 
rainy season the injury from such sources 
may be largely avoided. This would 
probably require a thorough application of 
Bordeaux Mixture 4-4-50 strength, 
once a month during the rainy season, 
applied only to the interior of the trees 
and avoiding the outer twigs and foliage 
as much as possible. This system of 
spraying, however, will invite trouble 
from scale insects and it may be made 
use of only in extreme cases. There are 
many groves in which a thorough prun¬ 
ing may keep the disease sufficiently in 
check and there are others in which more 
drastic measures will be necessary. 
In general I would suggest that a 
thorough pruning be made at once to re¬ 
move all dead wood from the trees and 
that an application of Bordeaux Mixture 
should follow immediately as a means of 
disinfecting the same. 
WITHERTIP 
(Colletotrichum gloeosporioides Penz.) 
In conjunction with other troubles, 
Withertip will also do its share of injury 
to citrus trees during the present season. 
This is a fungus disease that kills the 
twigs and branches and it often causes 
serious damage when it becomes fully es¬ 
tablished in the citrus tree. The fungus 
is a weak parasite and attacks only trees 
of low vitality or those that have been 
severely injured. Owing to their weak¬ 
ened condition, citrus trees will be very 
susceptible to attacks of Withertip for 
several months and trees that have been 
severely injured by the cold will require 
extra care during this period. 
By improving the vigor of such trees, 
much can be done to prevent attacks of 
Withertip. Where the disease has es¬ 
tablished itself in the tree a thorough 
pruning will be‘necessary to eradicate it 
following about the same method that 
has been advised for Melanose. Trees 
that have been pruned for the disease 
should be watched through the season and 
if Withertip becomes active again, further 
pruning will be necessary. 
