A New Forest Problem 



When the white pine blister rust was discovered in 

 one or two spots in Minnesota in the spring of 1916 

 very little was known about the disease or its distri- 

 bution in this state. Its life history was known from 

 European studies and its spread in New England had 

 attracted some attention, but the extent of that spread 

 was not definitely known. It was thought that if the 

 infections found that summer were the only ones in 

 the state there might be a chance of stamping out the 

 disease. 



This attempt at eradicating the disease and the 

 search for further infections was clearly a problem 

 for the plant pathologists. But since the authority to 

 carry on such work was vested in the state entomolo- 

 gist the two departments were obliged to cooperate 

 in' the work. This policy was followed during the 

 summers of 1917, 1918 and 1919. 



By the fall of 1919 it had become quite evident that 

 the disease could not be stamped out of the state. It 

 had, however, been pretty clearly established that it 

 could be controlled to a certain extent. That is, the 

 disease could be kept out of certain definite patches 

 of timber wherever the currants and gooseberries the 

 alternate hosts of the rust were eradicated from the 

 timbered area and from a zone of 1,000 feet wide 

 around the timber. This, of course, could be done 

 only where the pine was valuable enough to warrant 

 the expense. 



This possibility of control brings it withiu the realm 

 of the forester and presents it as a new problem in 



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