THE INSECT CAMPAIGN lOI 



but this method is so impracticable as a general treat- 

 ment that it need not be described. 



The only truly practicable method of controlling the 

 scale in orchard practice is by spraying; and the cheap- 

 est and most effective spray known at this writing 

 (1908) is the lime sulphur mixture. (Formula on 

 page 137.) Very thorough spraying in early spring 

 with well-made lime-sulphur spray is plainly the best 

 treatment to be recommended. In southern localities, 

 where there is considerable open weather during the 

 winter, much of the spraying can be done at that 

 season. 



Next to the lime-sulphur mixture the best remedy 

 for San Jose scale now known in unquestionably some 

 one of the so-called "soluble oils." These are specially 

 prepared petroleum products, and for the present are 

 all sold under proprietary names. The most promi- 

 nent for the moment are Target Brand, Scalecide and 

 Kil-o-scale. These oils are put into water, with which 

 Ihcy mix more or less perfectly, and are ready for 

 immediate use. The amounts used vary from i part of 

 oil to 10 of water down to i part oil to 20 of water. 

 Under favorable conditions the mixture is perfect, but 

 in many cases the oil is only partly dissolved in the 

 water. Under such circumstances it is plain that the 

 strength of the solution will vary and that the results 

 may be seriously affected. There seems to be no injury 

 to the trees when these soluble oils are used during 

 the dormant season. 



These oils have the great advantage of being easy 

 to mix and use. They do away with many of the most 

 disagreeable features of the lime-sulphur treatment. 

 At present prices they cost from 10 to 25 per cent more 



