FEDERAL HORTICULTURAL BOARD. 611 



The Parlatoria scale is so destructive to the date pahn that tlie 

 experts of the Bureau of Plant Industry and all others who have 

 studied the matter agree that dates can not he grown in this country 

 profitahly unless the Parlatoria scale is completelv eradicat<^d. The 

 whole future of this promising industry, which is so admirably 

 adapted to the irrigatea valleys of the .Southwest, is therefore tied 

 up with the success of the Parlatoria eradication work. Several 

 million dollars have already been invested in date culture and the 

 industry is a rapidly growing one. 



During the past year a very efhcient corps of date-scale inspectors 

 has been trained, and rapid progress is being made in the work of eradi- 

 cation of the scale. The State and county ofTicers of California 

 and Arizona have ^iven most thoroughgoing cooperation in this 

 campaign of eradication. 



THE PINE BLISTKR RUST. 



The Federal quarantines on account of this disease are being 

 administered in cooperation with the Bureau of Plant Industry. 

 The important development in the v»-hite pine blister rust situation 

 was the discovery in the fall of 1921 of the establishment of this 

 disease in southwestern British Columbia and in the Puget Sound 

 region of Washington. The department, in cooperation with State 

 and Canadian authorities, took prompt action to determine the ex- 

 tent of the infected area and to control or eradicate this new outbreak. 

 The condition of the infected pines indicates that the disease must 

 have been present in British Columbia as early as 1911. The infec- 

 tion is widely distributed on native western white pine and cultivated 

 black currants in British Columbia, the most unportant location 

 being at Revelstone, about 120 miles north of Idaho. This year 

 cultivated black currants infected with the rust have been found 

 in Washington in the counties of Whatcom, San Juan, Skagit, Island, 

 Clallam, Pacific, and a single mfected planted pine (Pinus monticola) 

 was found at Blaine, Wash. In 1921 two small pines infected with 

 blister rust were found in a nursery at Mount ^'e^non, Wash. 



A Federal quarantine was established, coinciding with the Wash- 

 ington State quarantine and including the known infected area, to 

 prevent the movement of five-leafed pines, currant and gooseberry 

 plants out of that portion of Washington lying west of the summit 

 of the Cascade Mountains. ^ 



As to the eastern areas of blister rust invasion. Federal Quarantine 

 No. 26, which -prohibits the movement of blister rust host plants 

 from States east of and including Minnesota, Iowa, Missouri, Arkan- 

 sas, and Louisiana interstate to points west of the quarantine line, 

 has been continued to prevent the introduction and spread of the 

 disease into uninfected regions. In the enforcement of this quaran- 

 tine 70,180 shipments of nursery stock were examined for blister 

 rust host plants during the past year. There were intercepted 135 

 shipments in violation of the quarantine, 93 per cent of which were 



1 Owing to a recent change in Ihe Washington State blister rust quarantine, it has become necessary 

 to extend the Federal quarantine to the entire State of Washington, instead of only that portion of the 

 State west of the summit of the Cascades. 



