PROTECTION AGAINST FOREST DISEASES 



By CARL HARTLEY, J. S. BOYCE, and others l in the Bureau of Plant Industry 



CONTENTS 



Investigation 1419 



Organized control 1 423 



Service force for control application 1424 



INVESTIGATION 

 NECESSITY 



The first, and for a long time one of the principal, activities in any 

 program that can be laid down now with reference to forest diseases 

 is research. There are 180 native timber species in the country of 

 importance for production of wood, and still others that are of more 

 or less importance from the standpoint of aesthetics or watershed 

 protection, in addition to a few introduced species which demand 

 attention. To distinguish the different diseases which attack any 

 one of these tree species, determine their causes, find out what con- 

 ditions or forest management practices affect their spread and what 

 strains or varieties are resistant to them, requires many years and 

 the collaboration of mycologists, anatomists, physiologists, etc. To 

 cover adequately even the 25 most important tree species would take 

 not less than half a century with a force of investigators as small as 

 that now active in the field of forest pathology. Superficial studies 

 reveal ways in which a few diseases can be controlled or avoided, but 

 to get economically practicable methods of cutting down the losses 

 from most diseases it is necessary to know the fundamental facts 

 about them. 



SUBJECTS TO BE EMPHASIZED 



The State of New York is now beginning an extensive 20-year 

 program of acquisition and reforestation, by planting of lands suit- 

 able only for growing trees, involving the expenditure of about 

 $20,000,000. To a lesser extent, forest planting in the Lake States 

 may be increased in the immediate future and planting promises 

 to become more extensive in some of the other forest regions. This 

 planting will be almost exclusively softwoods and largely in pure 

 stands. Nursery capacity for providing stock will have to be 

 increased. Trees grown in nurseries and plantations have proven 

 more subject to disease than those naturally regenerated, so that in 

 these nurseries and plantations we can expect not only an increase 

 in the diseases at present troublesome in the wild stands, but a number 

 of new or little-known diseases which may cause serious damage. 

 These will require investigation and control. Furthermore, selec- 

 tion of seed from healthy mother trees from a locality with climatic 

 conditions similar to that of the place at which the trees are to be 



i S. B. Detwiler and W. W. Wagener, assisting. 



1419 



