At Eldred we had two difficulties in spraying. One was the type of machine with which I was not familiar and the other the inaccessibility of some of the trees. The machine is probably more fitted for field crop work than for large trees. It is called a Mechanical Aresol Generator, manufactured by the Hessian Microsol Corporation of Darien, Conn. The engine is a Wisconsin Air cooled motor made in Milwaukee, Wisconsin. The machine was mounted on a platform and transported in the orchard on a truck. Two fifty gallon barrels constitute the tank. Due to the nature of the machine and to lack of agitation only liquid materials can be used in it. It uses a much smaller amount of material than I had been accustomed to, and my first job was to learn to what extent the materials must be concentrated to compensate for the small output and how to get a comparison with the amounts used in regular orchard sprayer. In concentrate tests on fruit trees we arrive at this by judging the number of gallons which a tree would normally receive with a standard sprayer. There was little background to go on with nut trees and the problem was further complicated by the arrangement of trees which were not planted but grafted in their original positions in the woods. A clump of trees which could not be approached individually might have to receive not much more material than one tree which could be hit from both sides. Sizes of trees also varied. It was decided to use only 25 gallon lots of material and even this small amount sprayed from 55 to 65 trees of varying sizes. It was soon seen that the tops of the moderate and large sized trees were not covered very well. For the first brood sprays at Eldred about six times as much material per 100 gallons was used as had been successful at Anna the previous season. The results are shown in Table 6. Table 6. Spittle Bug Control, Eldred, 1952 First brood, sprayed May 23, examined June 9 ========================================================= Treatment Amount in Spittle masses 100 gallons 800 terminals --------------------------------------------------------- Dieldrin 1 gal. of 18-1/2% 18 Lindane 1 gal. of 20% 27 Check ------ 189 --------------------------------------------------------- It will be seen that the reduction over the unsprayed blocks was about 90% with Dieldrin and 85% with Lindane. For second brood sprays at Eldred materials were increased to about 8 times normal in hopes of getting better results. In this test 10 trees were selected in each block that could be reached moderately well and sprayed separately before the entire block was sprayed. Records were made the day before spraying, 3 days after spraying, and 10 days after spraying. Four materials were available, making five blocks with an unsprayed check. The results of these sprayings are given in Table 7.