The Palatka news and advertiser. [volume] (Palatka, Fla.) 1908-19??, 1910-07-15
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SUMMER PRUNING
FOR WlTHERTlP,
Press nulletin University of FLORIDA.
B y H. S. FAWCETT.



Press bulletin University of Florida.
Withertip is one of the worst fungus
diseases of citrus trees in Florida. In
the summer, trees affected by it may be
distinguished by the following and fall
ing of leaves on certain branches Ii
the disease is in an active condition, the
bare limbs from which the leaves have
recently fallen will be seen to be grad
ually dying back, suggestive of a slow
poisoning. The inside bark and cam
blum, nearer the body OF the tree than
the part already killed, will be abnor-
mally yellow, and sometimes the limbs
will be considerably stained. The
calyxes and peduncles of fruit dropped
in the spring turn brown, and under the
hand lens show small raised points.
How to Prune
1t is of the highest importance in pru-
ming for withertip to cut out so much OF
the wood as to get rid, not only of the
bare branches, but also of all the
branches that show even slight sign of
the disease. In severe cases OF withcr-
tip there are seen, in addition TO bare
branches, many limbs on which the yell
lowish leaves are about to fall. Close
examination will show that the disease
is slowly making its way back and poiS-
oning these limbs. This poisoning may
start from an infection at the tip, or
from an infection on a side branch
lower down, from which the poisonous
effect has spread TO the main limb.
Sometimes only one side OF a tree, or
only one branch, is severely affected;
while the remaining part OF the tree is
uniniured. The distance TO which the
disease has progressed can frequently
be seen by the presence of new shoots
with a sickly yellow color. Frequently
the leaves fall from such shoots before
they are half grown, leaving the bare
young shoots 10 dry up. Whatever may
be the conditions, ii is important TO get
rid of all these poisoned limbs. To
prune only half-heartedly usually makes
matters worse, rather than better.
When pruning, care should be taken to
make smooth cuts, usually at the base OF
a branch or limb, so as not TO leave any
projecting stubs. This precaution should
be rigidly carried out, because infection
in these stubs is almost certain TO occur
when the withertip fungus is present.
After pruning, paint the larger cut sur
faces with carbolineum, pine tar, or
grating wax.
The grove should be given unusual
care after severe pruning of this kind.
1t should be we'll fortified with a we'll
proportioned formula so as to bring
about vigorous healthy growth, and to
render the trees resistant to further at.
lacks of the fungus.
When to Prune
Summer pruning for withertip should
be done in July. 1t is important not
to delay the work beyond this date. Do
not prune while new growth is putting
out vigorously, for this is almost sure to
result in injury rather than benefit.
Begin the work at once, and do moi
consider the looks of the trees, but take
out everything that shows the presence
of the disease.
The beneficial results already obtained
on hundreds of acres of groves treated in
this way, under the direction of Expert
ment Station workers, have proved the
effectiveness of this treatment.
Other Effects of Withertip
Different results of the attack of the
withertip fungus are seen at other sea
sons Of the year. These vary according
10 weather conditions and the part of the
tree affected, and need different treat
ment. Some of these effects OF the dis