< 4 THE SAX JOSE OE CHINESE SCALE. " 



A year later (1901-2) very elaborate tests conducted by Doctor Forbes 

 in Illinois showed that fairly hard rains will not always invalidate 

 spraying with this mixture. A vast amount of experience of the most 

 practical kind since gained, contributed to by all the eastern experi- 

 ment stations and by the big commercial fruit growers of the Middle 

 and Eastern States, has fully demonstrated the practical merit of this 

 wash and its superiority to others in point of safety to trees and in 

 cheapness. The wash is furthermore a valuable fungicide and is nota- 

 bly useful against the peach leai curl, sprayed trees being practically 

 immune from this disease, so that the cost of treatment is often more 

 than made good bv the fungicidal benefit alone. Its disadvantiiges are 

 the difficulty of preparation and the heavy wear which it entails on 

 apparatus — objections, however, which do not ofiset its notable advan- 

 tages, particularly for commercial orchard work or where the number 

 of trees to be treated is sufficient to warrant the trouble of its prepara- 

 tion. It is, in fact, the standard spray now used in commercial orchards 

 for the San Jose scale. 



In the matter of composition of the wash scarcely an}' two experi- 

 menters agree. Salt was a part of the original composition of the sheep 

 dip and has long been retained, with the idea that it added, perhaps, to 

 the caustic qualities, and particularh' to the adhesive nature of the 

 wash. For the latter purpose a very small amount only. 1 or 2 pounds 

 to the bushel of lime, need be added, following the custom in the 

 preparation of whitewash mixtures. In practical experience, however, 

 the salt seems to have been of very little benefit and is therefore 

 omitted in the formula now given. The proportion of lime and sulfur 

 is a matter of some indifference. The mixture obtained is sulphide of 

 lime, and if an excess of lime is used it simply remains undissolved in 

 the mixture and adds to the whitewashing character of the application. 

 Too much lime is distinctly objectionable, however, because of the 

 greater difficulty of spraying and harder wear on the pump and nozzles. 

 The formula here criven is substantiallv the one which has been hith- 

 erto recommended by this Bureau, reduced to the 15 or 50 gallon basis, 

 or the capacity of the ordinary kerosene barrel commonh' used in its 

 preparation b}' the steam method. 



Unslaked lime pounds. . 20 



Flowers (or flour; oi sulfur do 15 



Water to make gallons. . 45 to 50 



The flour of sulfur, although requiring somewhat longer cooking, 

 seems to make as good a wash as the flowers of sulfur, but an hour of 

 thoro cooking is ample for either. Good quality stone lime should be 

 secured and slaked in a small quantity of hot water in the cooking 

 vessel, say one-third the full dilution. The sulfur, previously mixt 

 up into a stifi' paste, should be added at once to the slaking lime. The 



