76 DEPARTMENT OF AGRICULTURE. [Pub. Doc. 



zinnia, hollyhock, and cut flowers or entire plants of gladiolus 

 and dahlia, except the bulbs thereof without stems. 



New towns have been placed under quarantine as soon as 

 they have been found infested. To date, the borer has been 

 located in 126 towns, although in many of these the infestations 

 are very light. 



The Department has co-operated with the United States 

 Department of Agriculture in the enforcement of the quaran- 

 tines, the inspectors of both departments having been deputized 

 by each other, thereby increasing the efficiency of the inspec- 

 tion. 



White Pine Blister Rust. 



The white pine blister rust is quite generally distributed 

 throughout the State, but wherever control work has been 

 performed very satisfactory results have been noted. This 

 fungous disease is peculiar, in that it cannot spread directly 

 from pine to pine but must pass through intermediate stages 

 of development upon the leaves of its alternate host; that is, 

 any species of a currant or gooseberry which is technically 

 known by the Latin generic name of Ribes. This character- 

 istic offers a method of preventing the spread of the disease, 

 namely, the eradication of one of the hosts, the less valuable 

 in most localities in this State being the Ribes. 



In protecting stands of white pine from this disease, there- 

 fore, it is necessary to remove all wild and cultivated Ribes in 

 the immediate vicinity of the pines to be protected; in other 

 words, to establish a Ribes-free zone or area. The width of 

 this protective zone is a variable factor and depends upon 

 many conditions, such as exposure, relative elevations and 

 the presence or absence of a screen of vegetation. Recent ex- 

 tensive experiments conducted for the purpose of determining 

 the necessary extent of such a protective zone have demon- 

 strated that the disease can be effectively controlled locally by 

 destroying all Ribes within a radius of from 200 to 300 yards 

 from pine. 



Control work has been conducted by this Division in co- 

 operation with the Bureau of Plant Industry, United States 

 Department of Agriculture, the government matching dollar 

 for dollar all expenditures by the State and its co-operators for 



