REPORT OF THE FEDERAL HORTICULTURAL BOARD. 375 



The five-leafed pine districts of the eastern United States have 

 already been invaded or the disease has become so widespread that the 

 further protection of such areas by quarantine is impracticable. 

 There remained, however, the vast five-leafed pine areas of the Rocky 

 Mountain and Pacific slope regions so far uninvaded by this disease 

 and the problem was particularly to protect this area from infection 

 if possible. Inasmuch as no definite quarantine lines could be drawn, 

 the alternative was taken of securing a voluntary agreement from all 

 the nurserymen in the Eastern and Mississippi Valley States not to 

 ship any white pine, currant, or gooseberry stock west of the western 

 line of the following tier of States: North Dakota, South Dakota, 

 Nebraska, Kansas, Oklahoma, and Texas. 



LIFTING OF QUARANTINES ON ACCOUNT OF POWDERY SCAB. 



The domestic quarantine on account of powdery scab of potatoes 

 was lifted, effective September 1, 1915, by an order issued by the 

 Secretary of Agriculture, August 30, 1915. This action was taken as 

 a result of a thoroughgoing survey conducted by the board of all the 

 principal potato-growing regions of the United States which had been 

 subject to possible contamination by the receipt of seed potatoes from 

 infected districts in Maine and New York or from foreign sources either 

 prior to the establishment of a quarantine or as a result of the move- 

 ment of certified potatoes. This survey indicated conclusively that 

 the disease is limited by climatic conditions and normally is to be 

 feared only in restricted localities of the northern areas of the United 

 States. The survey made by the board in cooperation with the 

 Bureau of Plant Industry of this department has determined that the 

 disease now occurs, in addition to the previously known regions in 

 Maine and northern New York, in three places in Oregon, one in the 

 State of Washington and five in Minnesota. In view of the imprac- 

 ticability of determining by inspection the complete absence of the 

 disease from commercial shipments of potatoes and the apparently 

 little danger from the shipment of such potatoes to the principal 

 regions where these potatoes find their known markets for food or seed 

 purposes, it was deemed that there was not adequate justification for 

 the continuance of the quarantine restrictions on the movement of 

 potatoes from the infected districts. 



A corresponding order lifting the foreign quarantine on account of 

 powdery scab was promulgated December 8, 1915, effective January 1, 

 1916. 



NURSERY-STOCK IMPORTATIONS. 



The system of control of imported nursery stock established during 

 the first year of the enforcement of the plant-quarantine act has been 

 continued without material change. 



The regulations were revised, effective July 1, 1916. The most 

 important change is the provision that permits to import nursery 

 stock from countries which maintain nursery-stock inspection, and 

 permits to import orchids and tree seeds from countries which do 

 not maintain nursery-stock inspection, instead of being reissued each 

 year as hitherto, will be valid until revoked. This will result in a 

 great saving of clerical labor, and wnll otherwise facilitate matters 

 both for this office, the offices of the collectors of customs, and the 

 importers and foreign shippers as well. 



