058 ANNUAL REPORT OF THE Off. Doc. 



been i)lanted as fillers among apples, every fourth tree being the 

 latter. This variety was chosen especially because in previous years 

 it had shown more ro( Ihan the others in the orchard, and its trees 

 were well covered with blossoms. 



OUTLINE OF THE E.XI'ERLMEXT 



The plan of the experiment involved Ihree sprayinji;s and nint^ 

 diHerejQt treatments, with appropriate "buffers" and checks. In 

 the first spraying, all plots except (he checks were trealed alike, 

 usinj,^ lead arsenate, lime and water at the rate of 2-2-50. This 

 application was aimed primarily at the curculio and was applied on 

 May 19, just as the calyces or "shucks" were shedding. The second 

 application was made a little less than a month later, on June 11 

 and 14, the "data"' trees being all sprayed on the 11th. At this 

 time the different fungicide and arsenical combinations named below 

 were applied. In the third spraying, the arsenicals ^\ele omitted, 

 the application being made on June 24. For best results in con- 

 trolling the diseases this third apidication should have been deferred 

 for )} or 4 wrecks, since the fruit proved not to be ready to pick until 

 August 2o, or about 8 weeks after our last application, when it 

 should have been only about a month between these dates. All 

 treatments were under the same conditions, however, so that for 

 purposes of comparison the experiment was not appreciably af- 

 fected. 



The materials used in the second an:l third applications (with 

 arsenicals omitted in the third l were as follows: 



Check. (Unsprayed throughout). 



"Buffer." (Three rows of trees, sprayed as in Plot 3, tliat were 

 included between the data trees and uusiirayed portions to avoid 

 undue exposure of the former to sources of infection). 



Self-boiled lime-sulphur, 8-8-50; and lead arsenate, 2 pounds to 

 50 gallons. (Made as described bv Scott, in T^. S. D. A., Bur. 

 of Ent. Cir. 120:.5-7; and B. P. I. Bui. 174. 1910). 



Lime-sulphur solution, 1,003; and lead arsenate, 2-50; applied 

 lime-sulphur solution in all cases was made as described bj' the 

 writer in I'enna. Bui. 99, 1910. A density of 1,003 is approximately 

 equal to a dilution of 1 to 100 of our best commercial lime 

 sulphurs, those testing 1.30 Sp. Gr. or 331° Baume). 



Plot V. Lime-sulphur solution, 1.003; and arsenate of lime, 2 pints to 50 



gallons. (The arsenate of lime here and in Plot VIII was made 

 as described in Penn. Bui. 99). 



Plot VI. Lime-sulphur solution, 1,003; and lead arsenate S-.oO ; applied with 



carbon dioxide gas sprayer. (Thi.s was expected to eliminate the 

 burning by precipitating the sulphur, without losing the fungicidal 

 action). 



Sulfocide, 1 to 400; and arsenate of lime, 2 pints to 50 gallons. 



w'as not advocated by the manufacturer but was tried to determine 

 results, since we had evidence that the Paris Green recommended 

 was unsatisfactory). 



Plot VIII. Sulfocide, 1 to 400; and arsenate of lime, 2 pints to 50 gallons. 

 (Tried for reasons indicated in VII). 



Plot IX. Pyrox, 5 pounds to 50 gallons of water. (This is a commercial 



preparation of Bordeaux and Lead Arsenate, which has given good 

 results on apples. It was tried here a little stronger than the 

 manufacturers recommended, but apparently is not desiiable. for 

 peaches, as later results show). 



