BLISTER RUST APPEARS IN THE PUGET SOUND REGION 



By S. B. Detwiler 



npHE first evidence of white pine blister rust was found 

 -*- last September, when diseased cultivated black cur- 

 rant bushes were located at Vancouver, B. C, by the 

 Provincial plant pathologist. The scouting which fol- 

 lowed brought to light infected cultivated black currants 

 at a number of points on Vancouver Island and on the 

 mainland as far south as Chilliwack, B. C. A few in- 

 fected planted white pine and Cembran pine were found 

 at Vancouver. In the State of Washington, during No- 

 vember and December, rust-infected cultivated black 

 currants were found near Sumas City, Mount Vernon, 

 Everett and Port Townsend. At Mount Vernon three 

 small western white pines showed signs of young 

 cankers. 



The presence of diseased black currants is a serious 

 matter because it is only 

 through the agency of cur- 

 rant or gooseberry buslies 

 that the blister rust spreads 

 from one pine tree to an- 

 other. Fortunately, in the 

 Puget Sound region, to 

 which the rust infection 

 appears to be confined, 

 planted white pines are few 

 and the native western 

 white pines are sparsely dis- 

 tributed, forming less than 

 one per cent of the forest. 

 Wild currants and goose- 

 berries are present through- 

 out this region, but the one 

 that is most common is 

 known to be highly resist- 

 ant to rust infection. Plants 

 of other species are scarce 

 except in marshy places. 



All kinds of currants and 

 gooseberries harbor the 

 rust to a greater or less ex- 

 tent, but cultivated black 

 currants are particularly 

 susceptible to infection. At 

 practically all points where the blister rust was found 

 in the Far West, it was confined entirely to cultivated 

 black currants. Only two bushes of wild currants were 

 found diseased out of thousands examined, and the ma- 

 jority of black currants examined were free from the 

 disease. This fact, and the age of the cankers found on 

 the diseased pines, indicates that the blister rust was 

 introduced recently. This is borne out by failure to find 

 the disease previously, although considerable scouting 

 has been done each year in the Puget Sound territory 

 since 1917. At Vancouver the rust was present as early 

 as 1916, before the establishment of the quarantine pro- 



DISTRIBUTION OF FIVE-NEEDLE PINES 

 & WHITE PINE BUSTER RUST IN THE WEST. 



KsWM White IjImesCRmonticola., 

 P.lamhrtiana,.'Palbicaulis, P 

 floilis.P arista ta.Pbalfouriana 



L..,.. 



hibiting shipments of nursery stock of white pines, cur- 

 rants or gooseberries. 



A conference to consider the best means of dealing 

 with the blister rust situation was held at Portland, Ore- 

 gon, on December 19-20, 1921. The conference was 

 called by H. P. Barss, chairman for the Western Advisory 

 Board of American Plant Pathologists, and was com- 

 posed of about seventy-five representatives of lumber- 

 men's associations, forestry and conservation associa- 

 tions, state foresters, agricultural commissioners, plant 

 pathologists, railway officials, nurserymen and timber 

 owners. Officials of the Canadian and British Columbia 

 governments and members of the United States Depart- 

 ment of Agriculture were in attendance at the invita- 

 tion of the conference. The conference first 



gave consideration to all 

 the 



available facts on 

 situation, and through a 

 number of committees, 

 worked out a plan of action 

 uniting national, state and 

 private agencies toward 

 preventing the further 

 spread of infection, and if 

 possible, to stamp out the 

 disease entirely on the Pa- 

 cific Coast. Some of these 

 measures consist of addi- 

 tional quarantine restric- 

 tions in Washington and 

 British Columbia, the gen- 

 eral destruction of culti- 

 vated black currants as a 

 public nuisance in the 

 Northwestern States, and 

 the conduct of necessary 

 investigational and scout- 

 ing work as soon as pos- 

 sible. (Zultiivated valleys 

 and a wide arid belt form 

 a natural barrier to the 

 spread of the rust from the 

 Puget Sound region to the 

 principal commercial white pine forests of Idaho and 

 western Montana. British Columbia has already placed 

 the needed quarantines, and is contemplating scouting 

 and other action to determine the best means of cooperat- 

 ing effectively with the western states. 



The Western spirit of cooperation prevailed at the con- 

 ference. The Pacific Coast Nurserymen's Association 

 and railway officials offered aid in scouting for the dis- 

 ease and in quarantine enforcement. Several nurserymen 

 voluntarily offered to destroy all black currants and white 

 pines in their nurseries. State officials in Washington, 

 Oregon, California, Idaho and Montana offered the serv- 



