FLORIDA .STATE HORTICULTURAL SOCIETY. 
77 
This table shows the results of soaking 
oranges and lemons in water with pure 
cultures of fungus, or with pieces of dis¬ 
eased fruit, or with soil from under in¬ 
fected trees, as compared with soaking 
oranges in pure water. After soaking for 
stated time, each fruit was wrapped as 
for shipment and kept at about 85 degrees 
Fahrenheit. The figures show percent¬ 
age of decay from Stem End Rot in 3 
weeks after inoculation. Those soaked 
in pure water showed no decay from this 
cause. 
Having found out something about the 
habits of the fungus, how it infected the 
fruit, etc., the next question was to try 
some experiments to see what would pre¬ 
vent infection. Since the disease was 
somewhat similar to the Brown Rot of 
lemons in California we planned an ex¬ 
periment similar to one that had been 
carried out for that disease. We placed 
cultures of the fungus in jars of water 
and at the same time put into it certain 
disinfectants. We used copper sulphate, 
formalin, potassium permanganate, iron 
sulphate and ammoniacal solution of 
copper carbonate. The experiment indi¬ 
cated that the copper sulphate, copper 
carbonate and potassium permanganate 
would prevent infection, but it was not 
at all conclusive since it was found that 
the oranges on which the experiment was 
tried proved afterwards to have been af¬ 
fected with stem end rot before being 
treated. 
TREATMENT. 
Treatment or preventive means that 
suggest themselves as a result of study 
of the fungus and our experiments in in¬ 
fecting oranges and in preventing infec¬ 
tion are of two kinds: (1) Treatment in 
the grove to prevent the infection of fruit 
on the trees, and (2) in case oranges must 
be washed, treatment at the packing house 
to prevent oranges from infecting one an¬ 
other at the washer. Probably the most 
feasible treatment in the grove will be to 
use the ammoniacal solution of copper 
carbonate. This should probably begin 
as early as the first of September or 
sooner, judging from; the reports we have 
of the time when the decay begins. Bor¬ 
deaux mixture could be substituted for 
the ammoniacal solution at this time, and 
the ammoniacal solution used later when 
there was danger from staining the ma¬ 
ture fruit. I tried some experiments 
with the ammoniacal solution of copper 
carbonate in December, but this was prob¬ 
ably too late to get any marked results. 
However, the treatment did show some 
results, about 10 per cent, less stem end 
rot being found on sprayed than on un¬ 
sprayed trees. 
This next summer and fall I intend to 
take up some more extensive experiments 
in some orange groves. The second line 
of treatment will consist in treating the 
wash water with some disinfectant to pre¬ 
vent the fruits from infecting one another 
in the process of washing. It seems to 
me this may be done either by throwing 
into the tank a fungicide as is done for 
Brown Rot in California or perhaps bet¬ 
ter in allowing a spray of some fungicide 
to play over the oranges as they leave the 
washer. 
To sum up, the facts about stem end 
rot are that it is caused by a fungus re¬ 
lated to the water moulds. It attacks or- 
