-106- 
percent DDT wettable powder (A-20) in 100 gallons of water were compared. 
One application on May 9, when the walnuts were still extremely small, 
gave exceptionally good control. Tree3 sprayed May 9 and again on June 
26 gave as perfect control as could be expected. Although the results 
are very promising, much more work is needed before DDT can be safely 
recommended for commercial use.— Michelbacher et al. (259). 
Used at the rate of approximately 13 ounces in 100 gallons of water, 
DDT gave as good control of codling moth in a Mcintosh apple orchard in 
western New York as 3 pounds of lead arsenate in 100 gallons, the 
standard spray mixture. The addition of oil to the DDT spray increased 
its effectiveness considerably. A 3-percent DDT dust gave some protec- 
tion, but it was not nearly so effective as the spray.— Anon. (17). 
In a large commercial Bartlett pear orchard in the Sa-ramento River 
LCalif J area 8 large trees were selected for the DDT experiment. "When 
the investigation was started, 2 lead arsenate sprays had already been 
applied. The composition of the spray for one series was 2 1/2 quarts 
of 20 percent DDT in oil with emulsifier per 100 gallons of water; for 
a 8eoond series, 5 pounds of 20-percent DDT wettable powder (A-20) per 
100 gallons of water. The trees in eaoh series received 2 to 4 applica- 
tions. No codling moth .injury was noted at any time. The DTT suspension 
spray caused no discernible injury and gave excellent coverage. The 20- 
percent DDT in oil showed poor wetting, and spotted-leaf injury occurred. 
Red spider injury appeared earlier and was more severe in the DDT plots 
than it was in the remainder of the orchard receiving the regular lead 
arsenate and dinitro treatments. Analyses showed a higher deposit of 
DDT remaining on the fruit at harvest when the DDT was combined with oil 
than when DDT was applied in water-suspension form. All DDT deposits 
were below 7 p. p.m.— Borden and Jeppson (91). 
Results of small-scale orohard experiments at several laboratories 
indicated that DDT (0.5 to 1 pound per 100 gallons of spray mixture) is 
equal or superior to lead arsenate, cryolite, or nicotine bentonite. At 
Vincennes, Ind., 4 ounces of DDT with half the usual concentration of 
lead arsenate or nicotine bentonite reduced the number of wormy apples 
to less than half of that resulting from standard lead arsenate or nico- 
tine bentonite alone and as good results as DDT, 1 pound per 100 gallons, 
without any other insecticide. At Kearney svi lie, W. Va., four applica- 
tions of DDT, 1 pound per 100 gallons, gave almost perfect control of 
first-brood worms. At Yakima, Wash., (6 cover sprays), 3 pounds of lead 
arsenate gave 16.6 worms per 100 apples, #iereas 1/2 pound of DDT plus 1 
pound of pyrophyllite gave only 11.4 worms per 100 apples. At Poughkeepsie, 
N. Y., a 5-percent DDT dust wa3 more effective than a 20-percent lead 
arsenate dust or 20-percent lead arsenate dusts combined with oil. Both 
here and at Vincennes DDT dusts were not so efficient as the sprays.— 
Baker and Porter (81). 
Four midseason applications of emulsive summer oil containing DDT 
(about 2 ounoes per 100 gallons) with no sprays after July 17, gave good 
control. Jonathan apples in this heavily infested, poorly cared for 
