FLORIDA STATE HORTICULTURAL SOCIETY 
permanently to sleep. There is really 
little to be desired so far as insecticides 
are concerned in the direction of killing- 
insects. We have now arrived at the 
point where it is not so much a matter of 
the medicine to be used as the method of 
administering it. 
DISEASES THIRTY YEARS AGO. 
We have already discussed the discov¬ 
ery of kerosene emulsion, which intro¬ 
duced the period when rapid development 
occurred in the scientific study of insec¬ 
ticides and fungicides. 
At the beginning of This period we find 
that mal-di-goma, or foot-rot, was the 
disease uppermost in the minds of citrus 
growers. This disease raged in all its 
fury in the Azores from 1832, when in 
about a ten-year period, 25 per cent of the 
trees were destroyed by it. Then came a 
quiescent period and in 1873 t ^ e disease 
had nearly disappeared, due to handling it 
by preventive and curative methods. In 
1845 it spread to Portugal and eastward, 
reaching Messina about 1863, thence to 
Sicily. It is conservatively estimated that 
at least $2,000,000 damage was done by 
it. Prof. Briozi, an Italian plant patholo¬ 
gist records publishing on the disease and 
regarding the fungus Fusisporium limoni. 
Since the curative and preventive methods 
have been so well worked out and the 
treatment so successful no very serious 
attempts have been made in this country 
to establish the identity of the causative 
agent. 
This disease does not appear to have 
reached California, my investigations 
there lead me to believe that what is fre¬ 
quently called foot-rot in California is 
quite a distinct disease. Prof. Fawcett, 
who has spent a great deal more time in 
the study of citrus diseases in California 
than I have, concurs in this conclusion. 
In Australia the disease was found to 
be destructive around Sydney as early 
as 1867. 
The disease seems to have been absent 
from the Asiatic countries, Japan, China 
and India, during the time when it was 
quite prevalent in Europe, America and 
Australia. This rather indicates that the 
disease was of European origin. 
The first printed authentic notice of it 
in Florida dates back to 1876, and as late 
as 1880 it was of rather rare occurrence. 
From that time on the disease seems to 
have made rather rapid progress and has 
been disseminated to every citrus growing- 
region of the State. During the middle 
nineties it appeared to reach its culmin¬ 
ation of destructiveness. 
Scab is produced by the fungus known 
as Cladosporium citri. This was de¬ 
scribed by Prof. Lamson Scribner. 
The origin of this disease is pretty cer¬ 
tainly Asiatic. It was not noticed to any 
great extent until the latter part of the 
eighties. 
Dieback has probably been with us from 
the beginning since it appears to be due 
to physiological conditions. In the early 
part of the studies it was confused with 
other troubles. In one publication, for 
instance, we have a fine colored plate of 
dieback and the suggestion that it is due 
to insect attacks. 
The earliest information that we can 
Bull. Torr. Bot. Club, Vol. XIII, p. 181. 
