76 
FLORIDA STATE HORTICULTURAL SOCIETY 
ulation experiments carried on at the Ex¬ 
periment Station laboratory. To find out 
just how the decay could be transmitted 
to sound fruit I started a number of dif¬ 
ferent experiments. 
First we placed pure cultures of the 
fungus on the stem end and on other 
parts of the surface of sound fruit. We 
also placed pieces of previously rotted 
fruit on the stem end of other fruits. We 
also wished to determine whether or not 
the fungus could get into the fruit 
through the attached stems. For this 
purpose we had oranges shipped in from 
a point where we had been unable to find 
a trace of the stem end rot, with stems 
of various lengths from 3 inches to 1-2 
inch. 
The accompanying table shows the re¬ 
sult of these tests. We kept check in ev¬ 
ery case. This experiment shows that 
infection may be produced easily through 
the stem end, but with more difficulty 
through other parts of the surface. In 
most of these tests the oranges were kept 
at a temperature of 85 degrees F. in an 
incubator. In my last press bulletin I 
said that infection seemed to take place 
only through the cut end. This was based 
on some preliminary experiments at room 
temperature during the month of Decem¬ 
ber. At the cooler temperature at that 
time no infection took place except at the 
stem end of the fruit. Since that time I 
have found that infection may take place 
through other parts of the orange. In¬ 
fection also takes place easily under labo¬ 
ratory conditions through stems 3 inches 
and shorter. 
Table No. 1. 
Manner of Inoculation. Percentage of Decay 
Cultures on blossom end. 
Cultures 
on 
calyx, cut end 
waxed. 
Cultrues 
on 
end 
of 
stems. 
stem 
3 inches long... 
. 45 
Cultures 
on 
end 
of 
stems. 
stem 
2 inches long. . . 
. 50 
Cultures 
on 
end 
of 
stems, 
stem 
1 Vz inches long. 
.100 
Cultures 
on 
end 
of stems, stem 1 
inch long. 
.100 
Cultures 
on 
end 
of 
stems. 
stem 
Vz inch long. . . . 
.100 
Cultures 
on 
end 
of 
stems. 
stem 
0 inch long. 
.100 
This table shows the percentage of de¬ 
cay in oranges from inoculation with 
pure cultures of Stem-End Rot fungus. 
The figures are taken 3 weeks after in¬ 
oculation. Small bits of fungus were 
placed on parts indicated and a piece of 
wet cotton placed over them. The or¬ 
anges were then wrapped as for shipment 
and kept at 85 degrees Fahrenheit. 
We also wished to determine whether 
infection took place from the fungus in 
water. Fruits were soaked in water con¬ 
taining cultures, for varying lengths of 
time, and others in water containing 
pieces of diseased fruit and still others in 
soil from under diseased trees. 
As checks some test fruits were also 
soaked in pure water under identical con¬ 
ditions to those above. The second table 
shows the results of these experiments. 
These experiments show very clearly that 
infection may take place through the me¬ 
dium of water by means of pure cultures 
of the fungus, by means of pieces of pre¬ 
viously rotted fruits, and by means of 
soil from under infected trees. 
Table No. 2. 
Oranges. 
Manner of Inoculation. Percentage of D'ecay. 
With cultures in water, 4 hrs. 25 
With cultures in water, 7 hrs. 50 - 
With cultures in water, 24 hrs. 40 
With diseased fruit in water, 4 hrs. 50 
With diseased fruit in water, 7 hrs.100 
With diseased fruit in water, 24 hrs. 90 
With soil from under infected tree, 3 lbs. in water 
24 hrs .. 75 . 
Soil, air dried 16 days, 3 lbs. in water, 24 hrs_12 
Check. In water only—24 hrs. 00 
Lemons. 
With cultures in water, 24 hrs. 64 
43 Check. Ip water only.—24 hrs. 00 
