74 
FLORIDA STATE HORTICULTURAL SOCIETY. 
looked in good condition, it was estimated 
that one-third of the grapefruit dropped, 
due largely to the stem end rot. One- 
fourth o^the oranges were said to have 
been lost in the same grove. In another 
grove ten miles from this one, io to 50 
per cent, of the fruit was on the ground 
by the first of December and a large per¬ 
centage of this fruit developed the stem 
end rot, mostly after they had fallen from 
the trees. 
HISTORY. 
The first knowledge that I had of the 
existence of this disease was in November 
of last year when 4 specimens of grape¬ 
fruit were sent from Volusia county. 
Two of these fruits showed a softening 
at the stem end, without at first any dis¬ 
coloration on the outside. On examining 
the interior of the rag and pulp cells un¬ 
der the microscope, large fungus threads 
were seen which appeared to be quite dif¬ 
ferent from any that were known to oc¬ 
cur in connection with other decay of 
fruits. Cultures of this fungus were ob¬ 
tained from these fruits by the ordinary 
laboratory methods. 
The fungus when it grew up in the cul¬ 
ture dishes was different from any I had 
before seen in connection with citrus 
fruits. In a day or two letters came from 
two or three other places indicating that 
the trouble was more general. We then 
began to realize the seriousness of the sit¬ 
uation and I began some preliminary ex¬ 
periments to see if I could infect healthy 
oranges with this disease. I began first 
with grapefruit and then oranges, and 
found that almost invariably the fruit on 
which cultures of the fungus or on which 
pieces of diseased oranges were placed at 
the cut end of the stem, began to soften 
in from a week to three weeks’ time. 
DESCRIPTION. 
The fruit begins to soften and sink a 
little round the stem end, without the rind 
changing color. There is no blackening 
or moulding at first, and the rind remains 
intact over the softened interior. The rot 
proceeds inward along the fibers of the 
rag, and then outward to the pulp cells. 
At first both the inside and the outside of 
the fruit remain almost unchanged in col¬ 
or; but, as the softening goes on, the 
rind turns dull brown. Finally the rag 
and the pulp cells are disintegrated, and 
the entire fruit becomes soft and mushy. 
This rot usually occurs on full-sized 
fruits after they have colored. Though 
the softening may begin while the fruit 
is still hanging on the tree, it usually de¬ 
velops after the fruit has dropped or after 
it has been picked. 
The stem end rot is mainly but not en¬ 
tirely a decay of fully mature fruit and 
is usually seen on fruit after they have 
dropped or have been picked. The char¬ 
acteristic softening does sometimes oc¬ 
cur while the fruit is still hanging to the 
branches. This shows beyond doubt that 
the fruit may be attacked while yet on 
the tree, that in some way which we do 
not yet know, the fungus gets to the or¬ 
anges on the tree. How early in the de¬ 
velopment of the oranges the fungus may 
attack them I do not know. One grower 
who has had some stem end rot for two 
or three years past said that he first noticed 
