144 Report ok the Department of Botany of the 



THE DISEASE. 



The disease under consideration is one which is better known 

 as wilt, blight or cane blight. It is the disease first brought 

 to notice by Fair-child 1 in 1891 and described, in 1899, by 

 Stewart and Blodgett 2 in Bulletin No. 167 of this Station under 

 the name cane blight. In Technical Bulletin No. 18 of this Sta- 

 tion Grossenbacher and Duggar 3 have given an account of the life 

 history, biology and parasitism of the causal fungus, Botryo- 

 sphceria ribis Gross. & Dug. Presumably, the currant disease 

 studied by Durand 4 was the same ; if so, he was in error in ascrib- 

 ing it to Nectria cinnabarina. 



Briefly, the symptoms of necrosis are as follows: On certain 

 canes or portions of canes the leaves wilt, turn brown and die. 

 This may occur at any time while the plants are in foliage. An 

 examination of an affected cane will reveal, somewhere, a section 

 of dead wood one to four inches long. Here is the seat of 

 the trouble. The bark has been killed and the wood and pith 

 invaded by the mycelium of the causal fungus. This hinders 

 the ascent of sap and thereby causes all parts of the plant beyond 

 the point of injury to wither and die. To the casual observer the 

 symptoms of necrosis resemble those shown by canes attacked by 

 cane borers; but the difference is seen at once when an affected 

 cane is split open. The cane borer forms a conspicuous burrow 

 in the pith and, frequently, the larva itself is present; while in 

 canes suffering from necrosis neither burrow nor larva is to be 

 seen. By close observation one may detect a fine, whitish, cob- 

 webby mycelium in the discolored pith at the point of attack. 

 Its presence can generally be determined with the unaided eye 

 and nearly always with the aid of a good hand lens. 



1 Fairehild, D. G. Notes on a new and destructive disease of currant 

 canes. Bot. f,'a.~ 16: 2(52. 1891. 



2 Stewart. F. C, and Blodgett, F. H. A fruit-disease survey of the Hudson 

 Valley in 1899. N. V. (State) Sta. Bui. 167: 292-4. ISO!). 



3 Grossenbacher, J. G., and Duggar, B. M. A contribution to the life 

 historv, parasitism and biologv of Botryosphceria ribis. N. Y. (State) Sta. 

 Tech. Bui. 18. 1911. 



4 Durand, E. J. A disease of currant canes. N. Y. (Cornell) Sta. Bui. 

 125. 1897. 



