PRESS BULLETIN No. 96.
Florida AgrICultural ExperimentH Stalon.
BY P. H. ROLFS.
The first symptom of the disease that is noticed is the oozing of gum from
wounds occurring near the ground. Later on, the gumming ceases and the
bark dries, the portion that has become diseased breaking off. These foot-rot
wounds after they begin to heal are so characteristic, that when once seen
they are rarely mistaken. The extent to which the wounds spread depends on
a variety of circumstances. Sometimes they are very small, being not more
than a fraction of an inch in diameter and more or less circular in outline;
while at other times they may extend nearly or quite around the tree at the
ground. In such cases the wound is of an irregular shape.
Since we have known that the disease is infectious and understood the
conditions which favor its spread, a remedy can be much more successfully
applied. The following brief rules, if followed carefully and conscientiously,
will eliminate the disease from a grove, and in many cases save trees that
otherwise would be lost.
1. Remove the soil from about the crown and the crown-roots, at least as
far back as any disease occurs. The greatest care should be exercised not to
wound the roots in removing the soil. By wounding the roots, opportunity is
given for the microbes to enter, and it is altogether possible that some virus
of the disease may be on the implement used in removing the soil. A very
small, even an invisible amount of this virus, is capable of starting the dis-
ease in a new place; consequently, any tools or implements used about a foot-
rot tree should be thoroughly disinfected before-being used on a healthy one.
2. After the soil has been removed from the crown, cut out the diseased
parts. For this purpose a large pocketknife with a strong blade is a handy
instrument. The bark should be cut away as far as the disease occurs, which
can be easily told by a yellowish or dark discoloration of the inner bark. As
the disease rarely penetrates into the wood, it will be sufficient to remove the
8. After the diseased part has all been cut out, apply an antiseptic wash.
One of the most readily obtainable, and also one of the best, is crude carbolic
acid-using one part of the acid to one part of water. This may be applied
with a paint-brush, or with a swab. Most people find the latter the handier
of the two, and it can be readily made by wrapping the end of a stick with
some old cotton cloth.
August 29, 1908.
When the disease makes its appearance early in the year, it may be neces-
sary to repeat this operation a second time, or even more frequently. The
frequency with which the operation should be performed will depend upon cli-
matic conditions and on the severity of the infection.
4. After the above remedy has been applied, and no new cases of foot-
rot have been discovered for a period of two or three months, the following
wash may be applied to the trunks of the trees and to such larger roots as are
exposed: Three parts of slacked lime, mixed with one part of flowers of sul-
phur. The ingredients may be easily mixed by passing them through a sieve,
or by working them on the floor, very much as fertilizers are mixed. After
they are evenly mixed, place the powder in a tub or barrel, and add enough
water to bring it to the consistency of paint. The right amount of water can
easily be determined by trial. If the wash covers the surface well and flows
easily from the brush, it will be about right. The trunks of the trees and all
of the exposed roots should be given a thorough coating of this material.
In groves where foot-rot is just starting and where the wounds are all very
small, this wash alone will frequently be found sufficient. In groves where
foot-rot occurs on a considerable percentage of the trees, it will be best to
apply the wash to the trunks and larger roots of all the trees-those that are
not affected as well asithe diseased ones.
State papers please copy.