THE WHITE-PINE BLISTER RUST. 7 



tliis country. Indeed, if it is not eradicated it will finally spread 

 by natural means throughout the range of the eastern white pine from 

 Minnesota eastward and from Canada to northern Georgia and 

 Alabama. 



DANGER TO THE WESTERN STATES. 



The white-pine blister rust, however, also threatens two of the 

 most important lumber species of the western forests, namely, sugar 

 pine and western white pine. The mature stand of these two is esti- 

 mated to be worth $240,000,000. Both of these trees have been 

 seriously attacked by this disease in Europe. They are little grown 

 in the Eastern States where this disease is present; hence, we have 

 absolutely no experience to show what the disease may do in this 

 country to them. Aside from the consideration of the total valuation, 

 these two species reproduce readily, and the prospects are good that 

 they will form a very important part of the future forests of their 

 regions. Any reforestation which may be done within their range 

 is likely to consist largely of these two species. 



The limber pine, which is distributed throughout the Rocky 

 Mountain region, is known to take this disease in Europe. It, 

 together with the two above-mentioned pines, would furnish a means 

 for the spread of this disease over the entire Pacific coast and Rocky 

 Mountain regions. 



There can be no doubt regarding the danger from this disease if it 

 once reaches the Pacific coast or the Rocky Mountain regions, as it 

 has been found by experiment that the wild currants and gooseberries 

 of these sections are susceptible to the disease. Conditions in the 

 natural forests are such that if the native forest once becomes infected 

 there is practically no hope of controlling the disease there; hence, 

 the outlook is especially grave. 



The writer has no positive evidence that the white-pine blister rust 

 has ever been west of Indiana. Imported white pines of suspicious ori- 

 gin are known to have been shipped as far west as Illinois and Minne- 

 sota, but not beyond the natural range of the eastern white pine. 



The western forests are so separated from the eastern forests by 

 the arid Great Plains that the white-pine blister rust can reach the 

 former only through the shipment of diseased nursery stock from 

 the East; consequently, the supreme importance of preventing such 

 shipments. All 5-needle pine stock should be grown from seed in 

 the general locality where the trees are to be planted. Each State 

 west of the Missouri River should immediately enforce an absolute 

 prohibition of the shipment of 5-needle pines or of currants or goose- 

 berries from the section east of the Missouri and Mississippi Rivers. 

 Seed may be shipped with entire safety, so far as this disease is con- 

 cerned. The importance of such State quarantines can not be too 

 strongly urged. 



