352 Bush-Fruits 



This has led to different classifications and names at different times. 

 The first indication of the disease is the wilting of the leaves on certain 

 canes or parts of canes. These soon turn brown and die. A section 

 of dead wood will be found, from one to four inches in length, where 

 the bark has been killed and the wood and pith invaded by the 

 fungus. This prevents the movement of sap and the parts above 

 wither and die. The general appearance is much like that of the 

 work of cane-borers, but no burrows or insects are present. The 

 whitish mycelium within the pith can be detected by the aid of a 

 hand lens and sometimes even with the naked eye. 



The disease is known in different localities but has proved particu- 

 larly destructive in the Hudson valley. It is there considered one of 

 the chief obstacles to successful currant-culture. The plants are 

 rarely killed outright, but as they grow older more and more of the 

 canes are affected until so little fruiting wood remains that the planta- 

 tion no longer pays. While it varies in intensity somewhat from 

 year to year it never disappears from a plantation once attacked. 



A point of interest in connection with this fungus is that it appears 

 to be the favorite food of the American currant-borer, Psenocerus 

 supernotatus, which feeds upon the spores and growing parts, both 

 in the field and in collected material. 



Control. No practicable means of controlling the disease seems to 

 be known. Careful experiments in cutting out the diseased wood 

 at frequent intervals during the growing season failed to hold it 

 in check, in experiments made by the Geneva, N. Y., Experiment 

 Station. 

 References. 



Geneva, N. Y., Expt. Sta. Bulls. 167, 357 and Tech. Bull. 18. 



Cornell Univ. Expt. Sta. Bull. 125. 



CURRANT FELT-RUST 



Cronartium ribicola, Fisch, de Wald. 



This fungus, like some other rusts, passes one of its stages on one 

 plant and one on another. The other host-plant of this one is usually 

 the white pine, though other five-leaved pines may be affected. The 

 fungus lives from year to year in the pine, but the spores which are 



