FLORIDA STATE HORTICULTURAL SOCIETY 
131 
it. Young twigs, not the youngest, but 
the next to the youngest, are first at¬ 
tacked. Its first appearance is shown by 
a yellowing of the bark. Several of these 
spots, which soon become slightly de¬ 
pressed may appear on the twigs. As the 
disease progresses the outer layer of the 
bark turns brown and finally ashy-gray 
. in color. The diseased areas are now 
spotted with fine black specks. These may 
be the fruiting bodies. At this stage of 
the disease the only part remaining alive 
in the affected part is the inner or grow- 
. # _ 
ing part of the bark. Even this cambi¬ 
um layer is interrupted and has the ap¬ 
pearance of new bark that is being formed 
over a cut. When the twigs are girdled 
the leaves turn yellow and finally ashy- 
gray in color and drop off. Even leaf 
stalks may show separate infections. By 
this time, especially if the infection in the 
top is considerable, the bark in the region 
of the crown roots is found to be rotting 
away, and sloughing off from the tips of 
the small roots. At this stage of the dis¬ 
ease it is practically impossible to save the 
tree. In the earlier stages cutting back 
to the second large leader and painting 
cuts with carbolineum has checked the 
progress of the disease and apparently 
effected a cure. I have under observation 
two three-year-old trees standing adjacent 
to each other in a grove where the disease 
had advanced far enough to partially gir¬ 
dle the trees at the top of the ground. All 
of the diseased tissue was removed and 
burned. Likewise the entire top was re¬ 
moved and burned. All cuts were paint¬ 
ed with carbolineum. These trees now 
seem to be recovering. New bark is 
growing over the affected area about the 
crown roots, and a new top is being- 
formed. Professor Stevens has made re¬ 
peated cultures of the affected twigs. So 
far he has isolated only the withertip fun¬ 
gus. This, however, does not prove that 
the disease is withertip, though in some re¬ 
spects the two diseases are similar. This 
disease seems to single out vigorously 
growing trees. Prof. Stevens also said this 
same disease appeared when Prof. Faw¬ 
cett was in the State and from the same 
localities where it is now appearing. 
I have appended data to show that a 
systematic plan of spraying pays not only 
in increase of price received, but in the 
quality of fruit--'gathered from the trees. 
These two groves last year produced 
grapefruit that was badly scarred with 
lemon scab and shark-skinned, to say 
nothing of the rust mite action. The fol¬ 
lowing figures speak for themselves. 
Grove A for the season of 1913 and 14 
on 2^4 
acres of grapefruit produced as 
follows: 
Per cent 
No. Boxes 
each kind 
Blue 
2 
.607 
Red 
- 79 
24.OI2 
Yellow 
194 
58.966 
Plain 
- 54 
16.413 
3 2 9 
99.998 
For the season of 1914" 
15 the produc- 
tion was 
as follows: 
Per cent 
No. Boxes 
each kind 
Blue 
• - 2 93 
27.430 
Red 
721 
67.509 
Y ellow 
- 54 
5-056 
1068 
99-995 
