FLORIDA STATE HORTICULTURAL SOCIETY. 
29 
tain diseases are caused by unfavorable 
soil or fertilizer conditions. In short, 
they are the results of improper physio¬ 
logical surroundings. This line of re¬ 
search has been lately taken up by Pro¬ 
fessor Floyd, who will later tell you about 
gum disease, melanose, dieback, etc. 
WHITEFLY STUDIES. 
In combating our enemies we have 
two methods of proceeding; first, by 
artificial means; and, second, by en¬ 
listing in our (service the natural ene¬ 
mies or some other natural condition. In 
combating scale insects, many of us have 
conducted an uneven warfare by using 
insecticides and spraying machinery at a 
very considerable cost. Later it was dis¬ 
covered that we could enlist the fungi 
which are natural enemies of the scale in¬ 
sect, and so do this work at much less cost 
to ourselves. 
It will be remembered that Dr. Webber 
about twelve years ago reported to the 
Horticultural Society that he had discov¬ 
ered a fungus which grew parasiticallv 
upon the whitefly. This was a very 
great surprise to all of us and was eager¬ 
ly received. In connection with this work 
however, a great many difficulties arose 
which prevented a sufficiently rapid dis¬ 
semination of the fungi to annihilate the 
whitefly. Dr. Berger has reported to you 
from year to year his success in devising 
means for increasing the efficiency of the 
fungi and making it it easier to distribute 
them. We now know at least seven spe¬ 
cies of fungi that are parasitic upon the 
whitefly, and the indications are that there 
are still undiscovered species that will 
work for us if we will but give them the 
proper opportunity. 
Over 1,200 acres of citrus groves have 
been treated with whitefly fungi and vis¬ 
ited by members of the experiment sta¬ 
tion staff. In addition to this we have 
received letters from owners of several 
times as many acres stating that they are 
using this method. The whitefly fungi 
are being used in the following locations: 
Winter Park, Boardman, Titusville, 
McIntosh, St. Petersburg, Candler, Au- 
burndale, Orlando, Bartow, East Palatka, 
Plymouth, Palmetto, Ybor City, Fort 
Myers, Gainesville, Jacksonville, Alva, 
Buckingham, Bradentown, Manatee, De- 
Land, and Dunedin. 
CO-OPERATIVE EXPERIMENTS. 
These experiments are carried forward 
jointly with the citrus or vegetable grow¬ 
ers. As a general rule, the Experiment 
Station bears the expense of its agent, 
and a part of the expenses of making the 
experiment; the citrus or vegetable grow¬ 
er bearing the expense of maintaining the 
field and a part of the expense incident to 
carrying on the experiment. 
Co-operative citrus experiments are be¬ 
ing carried on at Lanepark. These are 
expected to' be continued for a period of 
ten years. Pineapple fertilizer experi¬ 
ments have been carried on at Jensen for 
a period of eight years. Citrus disease in¬ 
vestigations are being carried on at Bay- 
view. Celery fertilizer experiments have 
been carried on at Sanford, and celery 
disease experiments at Orlando and 
Bradentown. 
Co-operative whitefly experiments are 
in progress at Gainesville, St. Petersburg, 
Leesburg, DeLand and New Smyrna. 
The advantages to the Experiment Sta¬ 
tion can readily be seen from the fact that 
