414 MANUAL OF FRUIT DISEASES 
the cluster. The fungus evidently hibernates as pycnospores 
in pyenidia; in the spring these spores ooze out on the bark. 
Dead and decaying canes are sources of the inoculum. It has 
been shown that the fungus may live as long as four years on 
fallen dead canes. It is believed that the pathogene is carried 
in the soil particles on nursery-stock. Furthermore, the prac- 
tice of laying down and covering of canes with soil in the fall to 
protect them from winter-injury, is thought to spread the or- 
ganism. A perithecial stage has been discovered, but its réle 
is unknown. 
It is peculiar that the fungus may cause most serious damage 
in dry seasons. This is explained on the grounds that canes 
become infected during the first season of their growth, but 
do not show effects until the following year. Weather condi- 
tions have a positive influence on inoculation and incubation, 
but not on the growth of the fungus in the cane. 
Control. 
No definitely established remedial measures are at hand. 
Ordinarily plantations may be expected to recover, even if 
badly diseased for one year. As a precautionary measure, 
plants should not be selected from nurseries in which the cane- 
blight is present to any great extent. Since the fungus may 
live on fallen canes for four years, it is inadvisable to replant 
on soil within this time after a severe attack. In any case the 
old canes should be burned. Dead and diseased canes should 
be removed soon after the fruiting-season, and again in the 
early spring. If the disease is particularly troublesome, look 
for any wild blackberries and wild red raspberries in the vicinity 
of the plantation. Their destruction is one step toward elimi- 
nating the fungus. 
According to present knowledge, the application of fungicides 
is not promising. In some cases bordeaux mixture has been 
applied as follows: (1) when the canes are a few inches high; 
(2) subsequently at intervals of two weeks until the middle of 
