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Show Nevada Letter Tells of Spray Applications Lee S. Rogers, assistant county agent, received the following letter let-ter from Robert J. Whelan, county extension agent at Lovelock, Nev., in reply to his inquiry of spraying for insect pests there. "In our trials here we tried practically prac-tically all of the insecticides with the exception of a few and found that the DDT was the most enon-omical enon-omical and also gave the best results. re-sults. We also found that the ground rigs gave us better results than the plane spraying. We made two mistakes in our initial spraying for the aphids and these mistakes were not spraying early enough and also not using enough volume. In using the DDT the colume or coverage is very important depending upon the height of the alfalfa. When our alfal'fa was 10 to 12 Inches high, we used 25 gallons per acre of the DDT mixture with very good results. re-sults. I would suggest that where alfalfa alf-alfa is not to be used for feed for 30 days, that you use 3 quarts of 25 emulsible DDT with one quart of summer oil, plus 14 to 24 gallons gal-lons of water per acre depending upon the height of the alfalfa. The summer oil will go into solution and give you a better mixture all the way through even if it is ' a little more expensive than the die-sel die-sel oil. The above reccommendation is for group rigs. In using planes I would be sure to have a plane that would at least put out 10 gallons per acre to assure complete com-plete coverage. Later on during the aphid infestation, infes-tation, we used TEPP and Lindane due to the fact that the alfalfa would be cut for hay before the 30 day period was up. We used 2 pints of TEPP plus 1 pint of Lindane Lin-dane with 14 to 24 gallons of water wat-er per acre. This mixture worked very well. However, it is quite a bit more expensive than DDT. The percentage killed ranged from 50 to 95 depending upon the heighth of the alfalfa and the type of application. The higher per centage kill occurred when using a ground rig." |