8 Department Circular 263, U. S. Dept. of Agriculture. 



TESTS WITH SEVERAL BRANDS OF LUBRICATING OIL. 



Following the success with a 2 per cent lubricating-oil emulsion in 

 the experiments of December, 1921, it was decided to test several 

 different brands of oil sold in this district. For this experiment a 

 block of large Ben Davis trees, entirely incrusted with scales, in 

 the R. O. Pickens orchard at Bentonville, Ark., was available. A 

 200-gallon power sprayer with a pressure of 225 pounds, two rods, 

 and double angle nozzles was employed for this work. One man 

 sprayed from the ground and the other in the tower, spraying one 

 side of a tree row at a time. One 2(X)-gallon tank of spray material 

 was used for each plat. The results of the experiment are given 

 in Table 2. 



Plats 1 and 2 were treated, respectively, with a 1 per cent and a 

 IJ per cent emulsion of the Xo. 1 lubricating oil used in Plats 1 

 to 4 of Table 1. Plat 3 received a 2 per cent emulsion of the same 

 oil as that used in Plats 5 to T of Table 1. Plats 4 and 5 received 

 2 per cent emulsions of two other brands of oil which may be termed 

 No. 3 and Xo. 4 lubricating oils. Thus, this experiment embodied a 

 test of four different brands of heavy commercial lubricating oils 

 the analyses of which differed only slightly one from another. The 

 essential object of this experiment was to determine the comparative 

 effectiveness of several different brands of lubricating oil. For this 

 reason there was no need of an unsprayed plat for a check. Ex- 

 amination of the trees before spraying showed an abundance of 

 live scales. 



A very severe spell of cold weather occurred during the middle of 

 January, just before Plats 1 and 2 were sprayed. Again, during the 

 last of January and prior to the dates of spraying Plats 3, 4^ and 5, 

 very cold weather prevailed. On the dates of the applications rather 

 mild winter weather was encountered. Table 2 shows the mortality 

 of the scales resulting from the various oil emulsions. m 



Table 2. — Mortality of liihernating San Jose scales from spraying icith several 

 brands of luhri eating -oil emulsion, R. O. Pickens orchard. Bentonville, Ark., 

 1922. ^, 



Plat. 



Insecticide. 



Dosage. 



Date of 

 applica- 

 tion. 



Date of 

 examina- 

 tion. 



Num- 

 ber of 

 scales 

 dead. 



Niun- 

 berof 

 scales 

 aUve. 



Percent 

 of dead 

 scales. 



1 



2 

 3 



4 



5 



INo. 1 lubricating-oil 

 1 emulsion. 



No. 2 lubrioating-oil 



emulsion. 

 No. 3 lubricating-oil 



emulsion. 

 No. 4 lubricating-oil 



emulsion. 



fl^ gallons in 100: 1 per 



J cent. 



\2\ gallons in 100; U per 



I cent. 



3 gallons in 100; 2 per cent 



3 gallons in 100; 2 per cent 



3 gallons in 100; 2 per cent 



1922 

 Jan. 21 



21 



Feb. 3 



3 



4 



1922 

 Mar. 7 



7 



28 



27 



28 



3,265 



3,000 



1,500. 



2,100 



1,675 



35 

 6 



12 

 4 

 4 



P.ct. 

 98.94 



99.80 



99.21 



99.81 



99.76 



The weakened dosage of the No. 1 lubricating-oil emulsions in 

 Plats 1 and 2, respectively, gave a very good kill of scales. A 2 

 per cent emulsion of this same oil under similar orchard conditions, 

 as shown in Plat 1, Table 1, was very effective. Plats 3, 4, and 5 

 in Table 2 show a rather uniform killing of scales for 2 per cent 

 emulsions of three different brands of oil. 



