RASPBERRY CANE BLIGHT AND RASP. 
Bi Wwhoye YF EleOW S* 
F. C. Stewart AND H. J. Eustacs. 
SUMMARY. 
I. Cane blight is a disease of raspberries which causes the 
plants, either wholly or in part, to suddenly die, about the time 
the fruit is ripening. It is caused by a fungus which attacks 
the canes at some point, killing and discoloring the bark and 
wood, thereby causing the death of the parts above. It occurs 
more or less abundantly, and often destructively, in most of the 
raspberry plantations in New York. It attacks nearly all 
varieties of the raspberry, both red and black, and perhaps also 
the dewberry; but the blackberry is exempt. 
Inoculation experiments have shown that it is caused by the 
fungus Coniothyrium sp. Both new and old canes succumb to 
inoculation within two months. Natural infection occurs on 
new canes during summer and autumn, and, probably, also on 
fruiting canes in the spring. Infection often takes place in 
wounds, particularly those made by the snowy tree cricket and 
in “heading back” the new canes. 
The fungus is disseminated by means of infected nursery stock ; 
by wind, rain and washing of the soil; and in picking, pruning 
and laying down the canes. 
The bluish-black areas so common on new canes of red rasp- 
berry in August and September, and once thought to be the early 
stage of cane blight, are now believed to be due to the fungus 
Sphaerella rubina and comparatively harmless. Perhaps this 
is Miss Detmar’s bacterial disease. 
In an experiment at Charlotte, N. Y., Cuthbert raspberries 
sprayed three times during the spring with bordeaux mixture 
*A reprint of Bulletin No. 226. 
