CONTROL OF THE SAN JOSE SCALE \) 



Table 6. — Results of experiments ivith lubricating-oil emulsions made with 

 various emulsifiers, and in combination with Bordeaux mixture, on the San 

 Jose scale, Yakima, Wash., 1927 



[Approximately 2,000 scales and 1,500 apples examined in each test] 



No. 



Material used i 



Scales 

 dead 



Control 



Apples 

 scaly 



1 



Lubricating-oil (dark neutral 2 ) emulsion (1 pound of spreader to 



Per cent 

 100.0 



100.0 

 100.0 

 100.0 



100.0 



100.0 

 100.0 

 100.0 

 92.3 

 98.6 

 66.6 



Per cent 

 100.0 



100.0 

 100.0 

 100.0 



100.0 



100.0 

 100.0 

 100.0 

 77.2 

 95.8 



Per cent 

 0.38 



2 



Lubricating-oil (dark neutral 2 ) emulsion (3 ounces of spreader to 



1.72 



3 





.57 



4 





.47 



5 



Lubricating-oil (red engine 6 ) emulsion (1 pound of spreader to 

 2 gallons of oil) 3 ... .-. . . .._ _.. ....... 



.73 



6 



Lubricating-oil (red engine 5 ) emulsion (3 ounces of spreader to 

 2 gallons of oil) 3 __ . - . -.- . 



.82 



7 





1.31 



8 





1. 19 



q 



Lime sulphur, 5° B., one application 



.55 



10 





.91 



11 



Check 













i 4 per cent oil used in all of these tests. 



2 See specification No. 7 (p. 11). 



3 See formula No. 2a (p. 10). 



i See formula No. 4 (p. 10); 

 5 See specification No. 8 (p. 11). 



These experiments do not indicate that any difference may be 

 expected in commercial control from oil emulsions and from lime 

 sulphur. Neither is there any indication that the type of emulsifier 

 modifies the efficiency of the emulsion. 



COMPOSITION OF SPRAY MATERIALS 



The formulas used in preparing the oil emulsions tested are given 

 below. The characteristics of the oils used are also given. 



OIL EMULSIONS AND MISCIBLE OILS 



No. 1. — Lubricating-oil emulsion (soap emulsifier). Made accord- 

 ing to the Government formula. 5 



Oil 2 gallons. 



Water 1 gallon. 



Potash fish-oil soap 2 pounds. 



These materials are heated until the soap is dissolved and the mix- 

 ture comes to a boil. The mixture is then immediately pumped 

 twice with a bucket pump or other suitable pump, using about 60 

 pounds pressure. 



No. 2. — Lubricating-oil emulsion (casein emulsifier). Made 

 according to the Missouri Agricultural Experiment Station formula. 6 



Oil 2 gallons. 



Water 1 gallon. 



Casein spreader 4 ounces. 



The spreader is thoroughly mixed with the water, the oil is added, 

 the mixture is stirred, and is then pumped three times with a bucket 



5 ACKERMAN, A. J. PRELIMINARY REPORT ON THE CONTROL OF THE SAN .TOSE SCALE WITH 



lubricating-oil emulsion. U. S. Dept. Agr. Circ. 263, 18 p., illus. 1923. 

 6 Burroughs, A. M. Op. cit. 



