282 



The Ohio Naturalist. 



[Vol. XIV, No. 6, 



tion of its symptoms. In a later report (1911, p. IS), he speaks 

 of spraying experiments in connection with "Project III Rasp- 

 berry Yellows." 



He does not clearly distinguish between raspberry "yellows" 

 and raspberry cane blight. Interpretation of his results indi- 

 cates that spraying with Bordeaux mixture controlled both 

 diseases — a conclusion which is not in accord with the writer's 

 experience with raspberry curl. 



Fig. 1. Plants affected with raspberry curl showing the stunted growth 



and bushy appearance. 



Lawrence (1911), assigns various factors as a possible cause 

 of raspberry yellows, among them fungi, poor grainage, lack of 

 soil fertility etc. A "bacterial disease" of raspberries was re- 

 ported by Detmers (1S91) in Ohio. From the description of the 

 disease, the malady is undoubtedly the one under discussion. 



The name "raspberry yellows" has been and is used indiscrim- 

 inately to cover a multitude of syinptoms. In some instances 

 in which people have heard that there is such a disease as "rasp- 

 berry yellows," a case definitely diagnosed as such, because a 

 few yellow leaves happen to be ])rcsent. The true ras])berry curl, or 

 "yellows", has very definite, striking, characteristic symptoms 

 and should not be confused with unthriftiness of plants due to 

 cultural conditions nor to a drying or blighting of the leaves and 

 canes as brought about by raspberry cane blight. 



