REPORT OF THE SOCIETY 63 



Silver Scurf. It is confined to the skin of the potato tuber and makes 

 its appearance as ashy-grey spots on the surface. These become larger as 

 time goes on, and several spots may become confluent, thus covering a large 

 area of the tuber. The outer layers of the skin are killed by the fungus 

 and take on a different colour from the healthy skin. Owing to the silvery 

 sheen of the dead skin, and to the fact that it dries up and peels off readily 

 the disease has been given the appropriate name of "Silver Scurf." In many 

 cases, there is present, in addition, on the surface of these silvery spots 

 small black specks which are just visible to the naked eye. These are the 

 "sclerotia" of the fungus, that is, each consists of a dense mass of closely in- 

 terwoven fungus filaments, and by means of this the disease is reproduced. 



If a tuber affected with Silver Scurf be washed and kept fairly moist 

 for a few days the surface of the silvered spot appears as though a very 

 thin layer of soot were dusted over it. 



Summary of Controls Recommended. 



By Spraying: — Late Blight, Early Blight and leaf infections. 



By Treating Seed: — Common Scab, Rhizoctonia, in slight cases. 



By Selection of Seed: — Common Scab, Rhizoctonia, Blackleg and 

 Fusarium Wilt. 



By Roguing: — Rhizoctonia, Blackleg, Fusarium Wilt, Leaf Roll, Curly 

 Dwarf and Mosaic. 



With regard to the work which we are endeavouring to do along the 

 lines of disease work at the present time, potato inspectors are endeavouring 

 to show the farmers of the Maritime Provinces the above symptoms of dis- 

 eases, and also from actual experiments carried out in various districts 

 what can be done by spraying. Last season we carried on experiments 

 in many sections of New Brunswick with spraying and in every case had 

 increased yields from spraying of from 50 to 100 bushels per acre, showing 

 them on their own farms how Late Blight and other diseases may be control- 

 led even in bad seasons. 



