CONTROL, OF THE SAN" JOSE SCALE 



A test was also made in 1925 of the casemate oil emulsion with 

 and without additional casein spreader. The results, given in Table 

 4, are averages of two series of tests, one made on February 24 and 

 the other on March 13. The tests without additional spreader are 

 the same as tests 1, 2, and 3 in Table 3. For those with additional 

 spreader some of the same diluted material was used, casein spreader 

 being added to it at the rate of 1 pound to 100 gallons of spray. 

 The results obtained from the three dilutions are rather variable. 

 From these experiments it can not be said that the addition of the 

 spreader either increases or decreases the effectiveness of the oil spray. 



Table 4. — Results of experiments with casemate oil emulsions, with and without 

 additional casein spreader, on the San Jose scale, Yakima, Wash., 1925 



[Approximately 1,000 scales examined in each test] 



No. 



Material used 



Dilu- 

 tion 



Tests 

 made 



Without addi- 

 tional spreader 



With addi- 

 tional spreader 



Dead 



Con- 

 trol 



Dead 



Con- 

 trol 



1 



Lubricating-oil (brown neutral) : emulsion (case- 



Per cent 



oil 



2 



3 



4 



Num.- 

 ber 

 2 

 2 

 2 

 2 



Per cent 

 90.3 

 98.8 

 99.6 

 49.5 



Per cent 

 80.8 

 97.6 

 99.2 



Per cent 

 91.5 

 95.0 

 99.6 

 49.5 



Per cent 

 83.2 



2 



Do 



Do 



90.1 

 99.2 



4 



Check . 













See specification No. 6 (p. 11). 



2 See formula No. 2 (p. 9). 



Table 5 gives some results obtained with a combination of caseinate 

 oil emulsion and lime sulphur, and also with an oil emulsion contain- 

 ing coconut fatty acid. These tests were made on March 18, and the 

 scale was examined on April 18. The addition of weak lime sulphur 

 or fatty acid to the oil emulsion evidently greatly increases its effec- 

 tiveness, a kill of 100 per cent being obtained iri all cases, except 

 with the 2 per cent oil spray with fatty acid. The combination of 

 oil emulsion and lime sulphur has been used by a few growers, ap- 

 parently with good effect. In one case, 2,168 scales on a twig 

 sprayed with this combination were examined, and none was alive. 

 Unsprayed scales at that time averaged about 80 per cent alive. 

 This combination is very apt to burn the foliage and should never 

 be used except on dormant trees. 



Table 5. — Results of experiments icith lubricating-oil emulsion in combination 

 with iceak lime sulphur and with fatty acid on the San Jose scale, Yakima, 

 Wash., 1925 



[Approximately 1,000 scales examined in each test] 



No. 



Materials used 



Dilu- 

 tion 



Tests 

 made 



Scales 

 dead 



Con- 

 trol 



1 



Lubricating-oil emulsion; 1 commercial lime sulphur, 1 gallon to 



Per cent 

 oil 

 2 

 2 

 3 

 2 

 3 

 4 



Num- 

 ber 

 2 

 2 

 2 

 1 

 1 

 1 

 2 



Percent 

 100.0 

 100.0 

 100.0 

 99.7 

 100.0 

 100.0 

 53.1 



Per cent 

 100.0 



2 

 3 

 4 



Lubricating-oil emulsion; ' lime sulphur, 1 gallon to 25 gallons 



Lubricating-oil emulsion; '- lime sulphur, 1 gallon to 50 gallons 



Fatty acid-oil emulsion 2 . . _ __ . 



100.0 

 100.0 

 99.4 



5 



Do... 



100.0 



6 



Do 



100.0 



7 



Check 













1 See formula No. 2 (p. 9 ) 



2 See formula No. 5 (p. 10.) 



