Observations of Diseases and Insect Pests of Citrus 
C. W. Lyons, Tampa 
My observations have been confined 
more to foot-rot and gummosis than to 
other diseases. I have, however, found 
a great amount of withertip in old seed¬ 
ling trees and also in budded trees. 
Withertip, It is important to cut back 
trees affected by withertip. I had occa¬ 
sion two years ago to visit a grove where 
I recommended that two trees affected 
with this disease be cut back. This was 
not done, and now there are about thirty- 
five trees affected, which will have to be 
cut back practically to the trunk to save 
them. This quite clearly demonstrates 
the importance of pruning and above ev¬ 
erything else, burning the limbs cut from 
these trees. 
Foot-rot. I have encountered this dis¬ 
ease frequently among the old seedling 
trees, and the greatest benefits which 
have been derived from treatment have 
been accomplished by removing the dirt 
from the base of the tree, back about 
twenty-four inches, and down under the 
crown roots, allowing the air and sunlight 
to penetrate. I have seen more good re¬ 
sults from the air and sunlight cure than 
from any other method. A great many 
growers use some good disinfectant. 
However, if the. tree is badly affected 
there is no use treating the roots and al¬ 
lowing the dead and sick wood to remain 
in the top of the trees. I have seen this 
tried, and it has proven a failure for the 
reason that you cannot expect live sap to 
circulate through half dead wood. 
Sourness. Another disease that goes 
hand in hand with foot-rot is that of 
sourness, which is caused from the fer¬ 
mentation of leaves and trash, etc., which 
are allowed to accumulate and remain in 
the forks of old budded and seedling 
trees. If the hollows in the trunks of 
these trees are not taken care of, it is only 
a question of time until there will be no 
trees. I observed one grove where this 
rubbish or solid matter was removed with 
a small garden trowel, and a hole bored in 
the trunk of each tree, at the bottom of 
the cavity, thereby allowing the water to 
drain out. This treatment benefited the 
trees greatly, and in the same grove where 
there were trees that were not treated, 
a great many limbs were either blown off 
or fell down from being badly decayed. 
This is really a first aid method that costs 
very little, but naturally the cost of treat¬ 
ing a great many trees in a large grove 
has to be given some consideration. It 
should not be necessary to have a special 
man brought in to do this work, as it is 
very simple, and the grower should have 
very little trouble in doing it himself. 
Some growers may contend that this is 
only a makeshift and would not be a per¬ 
manent cure, for the tree, but from ob- 
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