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Graham ( 131 ) in 1939 recomrr.ended the following for control of the 
pea aphid in Maryland: 
Spray . — Three pounds of micronized cube or derris 
(U- percent rotenone), plus spreader, to 100 
gallons of water at 150 gallons per acre and 
500 pounds pressure. 
Dust. — Finely ground derris or cub^ (0.75 - to 1.0- 
percent rotenone) at 35 to Uo pounds per acre. 
The machine should not exceed 3 miles and the 
wind velocity 8 or 9 miles per hour. 
Rotenone-hearing materials used as sprays give satisfactory control 
of the pea aphid when timely and properly applied. Rotenone-bearing dusts 
are equal to rotenone sprays in reducing aphid infestation under extremely 
hot and dry conditions. The first application should he made when the 
aphid infestation is 10 per sweep of the net, with another application 
10 days later if the infestation increases. 
Graham and Cory (132) in August 1939 reported that recent experi- 
ments, consisting of large field plots, on the control of the pea aphid 
in Maryland indicate that rotenone-bearing materials have great possi- 
bilities in pea aphid control. In 193& plots sprayed with derris contain- 
ing 2.9 percent of rotenone gave a maximum increase of hoU percent yield 
over unsprayed plots. Further tests with rotenone-bearing materials in 
1937 ?nd 1938 confirm, in general, the results obtained in 1936. In 1937 
and 193s tests were made with — 
Derris (rotenone 2.9 percent) 2 or U pounds per 100 
gallons + sodium lauryl sulfate l/U or 1/2 pound 
per 100 gallons 
Ditto, h pounds per 100 gallons + Orth^x spreader (1:800) 
Ditto, 1 pound per 100 gallons + nicotine sulfate 1:3200 
+ soap 1:1600 
Derris (rotenone 3»S percent) 3 pounds per 100 gallons 
Agicide 1:200 
Bor.ide (rotenone 2 percent) 1:300 
Cube (rotenone U.U percent) 3 pounds per 100 gallons 
-+ sodium lauryl sulfate l/U pound per 100 gallons 
Fixed (stabilized) derris 3 pounds per 100 gallons 
Dust containing 0.75 percent rotenone. 
The authors concluded that 3 ye^rs of experience with derris as 
an insecticide for pea aphid control in largj field plots indicated that 
when the application is timely and thorough the results are satisfactory. 
One year's experience with cube in comparison vrith derris indicated that, 
even though the rotenone content of cube is higher than that of derris, 
the latter gives better control. Several years of experience on the tim- 
ing of sprays for per. aphid control show that the best results are ob- 
tained when the aphid infestation is not greater than 1 per tip or 10 
per sweep when the first application is made. If the- first spray is 
