280 MANUAL OF TREE DISEASES 



expected to spread as rapidly in a given season as it would in 

 more open country. 



Control. 



Although repeated attempts had been made since 1896 to 

 seciu"e a federal law which would prevent the entry of foreign 

 stock likely to harbor and introduce dangerous fungi and in- 

 sects, such a law was not enacted urftil 1912. The blister-rust 

 fungus had by that time become established in various locali- 

 ties in northeastern United States. The extermination of the 

 fimgus was attempted where it was known. In New York 

 all the known areas where foreign white pine stock was planted 

 were inspected yearly. The diseased trees and sdl cmrant 

 and gooseberry bushes within five himdred feet of them were 

 destroyed. When the fungus was found prevalent in western 

 jNIassachusetts in the fall of 1915, more extensive surveys were 

 planned for 1916 and as the result, the fungus was found to be 

 generally prevalent throughout the territory east of the Hudson 

 River and Lake Champlain. In 1917 it was found practically 

 throughout New York state. Despite the previous attempts 

 at its eradication in isolated areas and any efforts that may 

 be made at general control in the future, the fungus is now so 

 well established in this country that it will continue to spread 

 and exist wherever conditions are favorable. 



In certain regions in which the white and other five-needle 

 pines are important as ornamentals, the native wild species of 

 gooseberry and currant are very scarce. Such conditions 

 exist in the lower Hudson River valley and on Long Island. 

 In these regions this disease could easily be controlled if the 

 cultivated garden varieties of gooseberry and currant were 

 eliminated. However, when one neighbor grows one of these 

 plants and the next has five-needle pines to protect, no generally 

 satisfactory agreement will be reached in most cases. The 

 elimination of currants and gooseberries for a distance of one- 



