of years after It had been discarded elsewhere. At the present time, the Taylor 

 variety which is also very susceptible to virus infection can be grown success- 

 fully in the hill tovms at higher elevations although at lower levels elsewhere 

 in the state it quickly declines. 



Winter injury and disease, particularly virus infection, have been the two 

 chief causes for the decline of the red raspberry industry. Winter injury was 

 discussed in the January 1962 issue of Fruit Notes . 



Of the several diseases which attack raspberries, virus is undoubtedly the 

 most serious both because of its effect on the plant and because of the wide- 

 spread prevalence of the virus troubles. Popularly, two types of virus are 

 recognized, mosaic and leaf curl. These are complexes but not all the entities 

 which make them up have been identified although this is now being studied in 

 several places. 



The seriousness of the situation can be appreciated from the consideration 

 of its several aspects. Wild raspberries are very common in New England and are 

 probably universally infected. Virus is spread by aphids which are also common 

 in New England, at least at certain times of year. Aphids with virus in them 

 need to feed only a short time to transmit it to uninfected plants. Most stocks 

 of commercial varieties of raspberries are virus infected. Some are more tolerant 

 of virus than others and, therefore, are not so quickly or seriously affected. 

 There is no known source of virus-free Latham plants, our most important commer- 

 cial variety. 



Serious as the situation is, it is not hopeless. It has been found that 

 some varieties are much less attractive to aphids than others. This together 

 with greater tolerance of some varieties opens the way for the breeding of 

 varieties which are less likely to become infected and will be less seriously 

 affected if infection occurs. 



Research workers in the U.S.D.A. and Canada have been searching for virus- 

 free stocks of raspberry varieties. Those now available in virus-free condition 

 are: 



Red raspberries: 



Canby Muskoka 



Carnival Newbury 



Comet Ottawa 



Cuthbert Rideau 



Durham September 



Indian Summer Taylor 



Lloyd George Trent 



Madawaska Willamette 

 Milton 



Black raspberries: 



Bristol Morrison 



Cumberland New Logan 



Dundee 



