A DISEASE OF PINES CAUSED BY CRONARTIUM PYRIFORME. 19 



Common salt may be applied dry, provided it is fine grained and is scattered very 

 uniformly. Salt may be applied more uniformly, however, if- it is made into a satu- 

 rated solution (1 pound to 1 quarts of water). The latter is usually the most satis- 

 factory form. It should be used at the rate of from 3 to 5 tons per acre, depending 

 upon the character and rankness of the vegetation. 



Of the petroleum products, fuel oil is about the most satisfactory, although this is 

 sometimes difficult to obtain, and then only in barrel or tank-car lots. Near the oil 

 fields, crude oil as it comes from the well can be obtained cheaply and is quite satis- 

 factory. The petroleum products should be applied at the rate of from 300 to 400 

 gallons per acre. If small areas are to be treated, so that the matter of expense is of 

 little consideration, kerosene may be used. The petroleum products seem to be the 

 most effective of all when applied to narrow-leafed vegetation, such as grass; salt 

 seems to be the next in effectiveness on such plats, and arsenic third. 



A spraying outfit is best for applying liquid material, excepting the salt brine, with 

 which a sprinkling can or sprinkler will do faster work. The petroleum products are 

 very hard on the rubber parts of spraying outfits, but it is necessary to use a sprayer 

 in that connection on account of economy of application ; with very small areas where 

 economy is not to be considered the oils can be applied through a sprinkling can. 



In the forest under our present conditions and market values it 

 is not best to advise methods of elimination so expensive as have" 

 been given for the protection of nurseries. In badly infected areas 

 of young forest trees, all diseased trees should be cut out whenever 

 possible. This often can be done by the forest officer without very 

 great expense, owing to the small size of the trees. In lumbering, 

 trees diseased with catfaces or cankers should not be left for seed 

 trees, as their vitality has been lowered and they will not produce 

 as good a crop of seed as more healthy trees, and it is also highly 

 probable that the viability of the seed produced by such trees is 

 lower than that produced by more healthy trees. Again, trees with 

 such cankers are often capable of producing seciospores around the 

 border of the cankers and if allowed to remain for seed trees would 

 become centers of infection for the younger generations of trees hi 

 the new forest. 



