THE PROBLEM OF THE IMPORTED PLANT DISEASE 



AS ILLUSTRATED BY THE WHITE PINE 



BLISTER RUST 



HAVEN METCALF 



Bureau of Plant Industry, U. S. Department of Agriculliire 



Within the last few weeks the civilized world has stood aghast at 

 the stories told by survivors of the devastation wrought by the German 

 army in its retreat from Northern France. Particularly schrecklich 

 are the stories and pictures showing the rows of fruit trees cut down 

 without being utilized for fuel, apparently with no purpose other than 

 wanton destructiveness. But if we pause to think we realize that the 

 Germans did not do the worst that they could have done. The fruit 

 trees are cut down, to be sure, but others can be planted in their places. 

 We may expect in future years to see the old orchards completely 

 rehabilitated. But let us suppose that instead of simply cutting 

 down trees in Europe, any enemy should see fit to leave them standing 

 but thoroughly incoulated with diseases which would not only destroy 

 the present stand of trees but would prevent their future profitable 

 culture in the same territory. To take an extreme example, suppose 

 that some malignant person or nation should see fit to introduce into 

 Europe from America, the Colorado beetle, the pear blight, the chest- 

 nut bark disease, and the citrus canker. Surely the world would stand 

 aghast at this if its significance was generally realized, because this 

 would not only destroy or seriously damage the present generation of 

 plants concerned but would tax the agricultural resources of Europe 

 with a perpetual burden. No more fiendish blow to the economic 

 resources of a country could be imagined. Yet this is exactly what 

 we have allowed foreign nations to do to us without resistance, through 

 our lax laws regarding the importation of live plants, or rather through 

 our virtual absence of laws on this subject. We have permitted our 

 country to be invaded by not one but many — perhaps hundreds — of 

 diseases and pests which constitute a permanent tax upon our agri- 

 cultural and forest resources, and up to the present time we have made 

 scarcely any serious effort to prevent further invasion. 



The Bureau of Entomology has issued a large bulletin entitled 

 "A Manual of Dangerous Insects Likely to be Introduced in the 

 United States Through Importations." I understand that this 



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