412 MANUAL OF FRUIT DISEASES 
lesions are found most commonly on the canes (Fig. 120), 
although the berries may be directly affected. All or only a 
portion of a cane is involved, in which case the foliage suddenly 
wilts and becomes dry. Often only a single branch wilts; 
the remainder of the plant then continues normal activities 
and appearances (Fig. 120). Frequently only a portion of a 
cane is blighted, such symptoms becoming evident as soon as 
the leaves unfold 
in the — spring. 
Lesions commonly 
center about a 
wound left in prun- 
ing, from which 
point they extend 
downward. There 
is a tendency on 
black varieties for 
the disease to affect 
only one side of a 
cane. The dis- 
eased area is brown 
and the cane be- 
comes very brittle 
Fic. 120. — Raspberry cane-blight; healthy plants t 1 
on right, blighted canes on left. a such points. 
Very early in the 
blighting of a cane, black fruit-pustules of the pathogene 
appear on the lesions (Fig. 121); from these pustules 
masses of reproductive bodies ooze out on the bark, giving the 
affected portion a brownish smoke-colored appearance. The 
spots are not always limited in extent; in some cases they 
are generalized, the wood cracks, and the bark peels off at the 
lower portion of the affected cane. 
The cane-blight disease may be confused with the work of 
the raspberry-cane borer (Oberea bimaculata). But in cane- 
