REPORT OF THE SOCIET"X 67 



leafroll caused by Fusarium sp. Bacterial stem-rot or black leg (B. phytophtho- 

 rus) was present in one range, but was not serious. 



No late blight (Phytophthora infestans) appeared until September, when 

 during the last two weeks of the season we had heavy warm rains. As a result 

 of these rains there was a heavy loss of potatoes in storage principally from Fusa- 

 rium rots — combined with some late blight. This may be explained on the 

 basis that owing to warm rains in the latter part of the season the tubers did not 

 mature sufficiently before harvest and very slight injuries to the skin consti- 

 tute, under these conditions, a fertile source of trouble in storage. 



Raspberries, especially Cuthbert, suffered severely from curl and yellows- 

 At the same time many plants showed typical mosaic symptoms with no signs 

 of curl. There are two possibilities — the curl may be an advanced stage of 

 mosaic, or they may be two different diseases. Symptomatically they are 

 distinct and results of histological studies of the mosaic type agree with those 

 in tobacco, tomato, etc. Further work is in progress on this phase. 



Currants again developed the uredinal and telial stages of Cronartium 

 rihicola. This has occurred for the last six years without a diseased Pinus 

 strohus being found in the vicinity. 



Greenhouse. — As in the field, tomatoes, especially Livingston Globe and, 

 to a lesser extent, John Baer, suffered from mosaic. Septoria lycopersici, cau- 

 sing leaf spot, was present but was not serious. 



Seedlings of Chamaecyparis obtusa and Pinus Koraiensis were damped off 

 by a Fusarium. 



Snapdragon rust (P. antirrhini) becaume so serious that new seed had to 

 be obtained and all old stock discarded. 



Storage. — Mention has already been made of potato losses in storage owing 

 to unfavourable weather conditions and infection by Fusarium spp. 



In apples black rot was fairly common, some excellent mummies with pycni- 

 dia being obtained. 



Many complaints were made from the Montreal market that apples were 

 packed so that the stalk of one apple pierced the skin of the one above. The 

 injury was followed by infection with Penicillium glaucum, which rapidly 

 caused a soft rot. 



