RASPBERRY DISEASES 



1773 



part of infection which occurs upon the 

 canes and leaves in the fall. Since very 

 little experimentation for the control of 

 this disease, particularly on the logan- 

 berry, has been carried on under Oregon 

 conditions, the above remarks on spray- 

 ing should be considered as suggestive 

 rather than as definite recommendations. 

 It is hoped that careful experiments may 

 be carried out by the Department of 

 Plant Pathology at an early date. 



Crown Gall 



The disease known as crown gall or 

 root knot is a common one on a large 

 number of trees and small fruits as well 

 as upon many herbaceous plants. 



On the cane fruits crown gall is known 

 particularly as a serious disease of the 

 loganberry, blackberry and raspberry. 

 See under Apple. ' 



Mushroom Root Rot 



The trouble known as mushroom root 

 rot, which has attracted so much atten- 

 tion as a disease of apples and prunes in 

 some sections of the Northwest, is known 

 also as a disease of cane fruits. This dis- 

 ease has been reported as a serious 

 trouble on cane fruits only in the North- 

 west. See under Apple Diseases. 



Raspberry Cane Blight 



Coniothyrium fuJcelii 

 P. J. O'Gara 



In 1910 the attention of the writer 

 was called to what appeared to be a new 

 disease to those engaged in growing 

 blackberries, raspberries, loganberries 

 and other related varieties in the Rogue 

 River country. The disease has shown 

 marked virulence in some places and 

 with some varieties. 



Causes of the Disease 



The disease has been named raspberry 

 cane blight, although it attacks blackber- 

 ries, loganberries, and other related vari- 

 eties of the blackberry family. It is 

 caused by a fungus (Coniothyrium fu- 

 Jcelii J, which produces minute spores in 

 enormous numbers. 



These spores when blown about by the 

 wind, or carried in any other way to the 



raspberry canes, are capable of germina- 

 tion when the proper temperature and 

 moisture is present. Once the spores 

 germinate and send their little root-like 

 threads into the canes, destruction of the 

 canes begins. After the fungus has vege- 

 tated within the canes for some time, it 

 is found that the canes begin to wilt, 

 and dead areas from which new spores 

 come may be seen. When the spores are 

 being expelled the dying canes often have 

 a smutty appearance on account of the 

 presence of countless numbers of these 

 minute globular bodies. A close inspec- 

 tion of the diseased cane shows that the 

 diseased patches on it are covered with 

 minute pimples or pustules. 



Varieties Diseased 



Observations in the field show the fol- 

 lowing varieties to be affected: Gregg, 

 Mammouth Cluster, Cumberland, Cuth- 

 oert. Amongst dewberries, Lucretia and 

 Primus. The loganberry. Amongst black- 

 berries, Mercereau and Blowers. The 

 Gregg seems to be most susceptible, while 

 the Golden Queen, a yellow variety, and 

 the Phenomenal are least affected. 



Fij?. 1. Raspberry Cane Blig:ht. Badly dis- 

 eased blackcap (Grej^s Variety). Note the 

 small size of leaves and berries, and wilted 

 condition. 



