— 27 — 

 During the past two seasons (1918-1919) an effort has been made to im- 

 prove the potato crop in Southern Ontario. This involved disease surveys of the 

 potato growing sections of Southern and Northern Ontario ; a system of inspec- 

 tion and certification for disease in seed potatoes, and the testing for disease and 

 yields of potato seed grown in Northern Ontario, Southern Ontario and New 

 Brunswick. 



The seed from these sources was grown side by side on eighty different plots 

 in forty counties of the Province during the past two years, and records kept of 

 the percentage of serious disease and yield per acre. The results obtained and the 

 observations made during the carrying on of this work may be summarized as 

 follows : — 



Seed potatoes grown in Northern Ontario are freer from Leaf Roll and 

 Mosaic and give larger yields per acre than those grown in Southern Ontario and 

 New Brunswick. Leaf Roll is especially prevalent and severe in the Southern 

 and South Western portions of Southern Ontario. In most sections of Southern 

 Ontario, Leaf Roll appears to spread and cause more loss each year that the same 

 seed is used. In Northern Ontario, Leaf Roll does not seem to spread nor to in- 

 crease appreciably in amount from year to year in the same stock. Under climatic 

 conditions such as we have in Southern Ontario, Mosaic appears to be suppressed 

 some years. That is, when seed from Mosaic stock is planted in some seasons, no 

 Mosaic is observed in the resulting crop. In Northern there appears to be no such 

 suppression of Mosaic, it apparently appears in infected stock year after year. 

 Mosaic evidently spreads in the one year from diseased to healthy plants and one 

 of the chief agents in its transmission appears to be the Leaf Hopper (Empoasca 

 mali Le Baron.) 



"A neiv disease of the poplar", by A. W. McCallum. 



A disease, well-known in Europe, caused by N apicladium Tremulae {Frank) 

 Sacc. is recorded for the first time on this continent. It is characterized by the 

 death of young shoots and the shrivelling of the leaves. Only the conidial stage 

 "has been observed as yet, this being common on Populus tremul aides and P. 

 grandidentata in Ontario and Quebec. 



"Some data on peach yelloivs and little peach in Ontario" , by L. Caesar. 

 The first appearance of yellows in Ontario was about the year 1874 and of 

 little peach about 1895. The outbreak reached its culmination in 1911 when there 

 was a loss of approximately $1,000,000. Experiments to prove transmissibility of 

 the disease gave varying results but orchard inspection and past experience tend 

 to show that the removal of diseased trees is by far the safest plan, especially as 

 a safeguard against an epiphytotic. 



At the close of the session Dr. Rankin and Prof. Eraser were named a com- 

 mittee to consider the taking of a plant disease survey of the Dominion. 

 The following officers were elected for 1920: 



President Dr. A. H. R. Buller 



Vice-President Dr. J. H. Faull 



Sec.-Treas Dr. R. E. Stone 



Councillor Prof. J- E. Howitt 



Councillor F. L. Dravton 



