300 AGRICULTURE OF MAINE. 



through scabby seed and through manure which contains hv- 

 ing spores of the scab fungus. 



On account of the importance of this disease it has been 

 made one of the chief hues of investigation. Methods have 

 been perfected for the disinfection of seed so that land which 

 is free from scab may not become contaminated by the use of 

 seed carrying the fungus. Experiments are under way which 

 are intended to throw hght on the cpiestion of the length of 

 time the scab fungus, under different systems of soil manage- 

 ment, will persist in the soil thus causing the production of a 

 scabby crop even though clean, disinfected seed is planted. 

 Soil which produced a very scabby crop from clean seed in 

 1909 has been secured and is being kept under control condi- 

 tions to determine how long the organism will live when no 

 plants are allowed to grow and in other cases when certain 

 plants which are not known to serve as hosts for this fungus 

 are grown. This is a question which it will probably require 

 many years to answer as it is well known that scab frequently 

 <:auses great damage to crops from clean seed on land which 

 has not grown potatoes for long periods of time. 



Uncooked, scabby potatoes are frequently fed to farm ani- 

 mals. Work is being done in order to determine the extent to 

 which the manure of different kinds of farm animals carries 

 living material of the fungus when fed in this way. So far 

 this work has been confined to experiments with the horse and 

 cow. 



BLACKEEC DISEASE OE THE POTATO. 



The blackleg disease of the potato has become of great 

 importance in Maine. The amount of actual loss in the crop 

 caused by this disease is not so great as that caused by some 

 others in this State but when Maine potatoes are shipped South 

 for seed, blackleg does much more damage in that section. 

 Therefore, it has become necessary, if Maine is to retain the 

 southern seed trade, that the potato growers should know and 

 apply methods for the elimination of this disease. 



Field and laboratory studies upon this disease and upon the 

 organism causing it have been under way for about 5 years. 

 The results of the past season's experiments give every reason 



