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FLORIDA STATE HORTICULTURAL SOCIETY"' 
SOME WAYS OF SPREADING CITRUS CANKER 
A. M. Henry 
Mr. President, Ladies and Gentlemen : 
It is hard to comprehend the ease with 
which citrus canker may be carried. If 
some one had made the statement a year 
agO' that as much care would be exercised 
in handling citrus trees as the surgeon ex¬ 
ercises in performing a major surgical op¬ 
eration, he would have been smiled at, 
yet such is the case today with the groves 
in the canker-infected districts. 
When the grower, upon waking in the 
morning, hears a mocking bird singing 
outside the window, he wonders if it has 
flown from the infected grove across the 
road. The grower, on going out to feed 
the mule before breakfast, finds that it 
has kicked the barn door down and wan¬ 
dered through his neighbor’s infected 
grove, and then decided the grass at home 
is better. Has he brought some canker¬ 
ous spores back with him ? In the morn¬ 
ing, when: the grower goes out to work 
in his grove, he notices that the insects are 
flying with the wind from the nearest in¬ 
fected grove. How many spores of the 
disease do they carry on their feet and 
mouth parts? In the afternoon a friend 
visits the grower, and after he is shown 
over the grove with a nice crop of young 
fruit on it, the friend innocently remarks 
that he hopes there is no danger, as he 
has just been looking at canker in the 
grove of Mr. Jones, where the inspectors 
have just found it, and it looks as if it 
might be a bad thing to have in a grove. 
The friend manages to get away without 
serious damage, if he is lucky. After sup¬ 
per, when the grower sits down to enjoy 
a quiet smoke, he hears a yellow cur chas¬ 
ing a rabbit through the canker-infected 
grove across the road and then through 
his. He gets out his gun and takes a 
chance shot, hoping that the rabbit in his 
haste left all canker spores. Finally 
the growler lies down to sleep, but a 
cricket so persistently chirps outside of 
his window that he dreams canker has 
been carried into his grove by crickets, 
and twenty-seven trees burned. Woe is 
the grove owner in the canker-infected 
district. 
As examples of the ways in which can¬ 
ker has been spread, the following are 
characteristic. From grove to grove: An 
ice wagon spreads canker to several 
groves along his delivery route from one 
infected tree that rubs the wagon. A 
flock of blackbirds are responsible for the 
scattering of canker to the yard trees in 
a small village. A wagon in which can¬ 
ker-infected nursery stock was hauled 
held spores for several days until some 
clean nursery stock ,was hauled in it, 
which later developed canker. A cow in 
the habit of following a path through two 
groves spread the canker along her trail 
from the infected grove to the clean 
grove. Important is man in the spread of 
canker by carrying it. “Typhoid Mary” 
has nothing on “Canker John,” who 
while himself not affected by it, yet seems 
saturated with it. In actual life “Canker 
