70 DECIDUOUS ERUIT INSECTS AND INSECTICIDES. 



of systematic care. But for various reasons, principally that of 

 neglecting to apply sprays at proper times and in a thorough man- 

 ner, the results had been very unsatisfactory. The work herewith 

 reported, and carried out in cooperation with Mr. W. M. Scott, of 

 the Bureau of Plant Industry, included the entire orchard and was 

 designed to give freedom from the codling moth and fimgous diseases 

 as well. The entire orchard was sprayed except a few trees for pur- 

 poses of comparison. 



Location of unsprayed trees used in determining results. — The un- 

 sprayed trees used for counts of fruit in this demonstration were 

 selected just prior to the first spraying. With two exceptions the 

 trees were in each of two rows running through the middle of the 

 orchard, five rows apart. Two pippin trees (one to be sprayed and 

 one to be left unsprayed) were also selected near the edge of the 

 orchard for possible comparison with other treated and untreated 

 trees. 



Treatment. — As bitter rot and apple scab had in previous years 

 caused serious injury to the fruit in this orchard, a treatment was 

 planned to control both insects and fungous diseases, namely, the 

 application of Bordeaux mixture with an arsenical added. Six 

 applications of Bordeaux mixture were made, using for the first 

 application 4 pounds of bluestone and 6 pounds of quicklime to 

 50 gallons of water, and for the subsequent applications 5 pounds 

 of bluestone and 5 pounds of quicklime to 50 gallons of water. Arse- 

 nate of lead, 2 pounds to 50 gallons of the mixture, was used with 

 the first, second, and fifth applications. 



Times of aiyplication. — The first application (4-6-50 formula of 

 Bordeaux mixture plus 2 pounds arsenate of lead) was applied just 

 after the blossoms fell, to fill the calyx cavities of the apples with 

 poison, and, owing to continued unfavorable weather, was very 

 much prolonged, from April 30 to May 9. The second application 

 was made three weeks later, about the time it was thought that the 

 moths from the over-wintering larva? would begin to deposit eggs in 

 numbers, that is, from May 21 to 27; the third application, five 

 weeks later, June 24 to 26; the fourth, July 10 to 13. The fifth, 

 containing arsenate of lead, for the second brood of larvae, was 

 applied soon after the first atlults began to emerge from the cocoons 

 of the first-brood larvae, July 25 to 29. The sixth, being the last, 

 was a treatment with Bordeaux mixture alone, and was applied 

 from August 12 to 15. 



The outfit used consisted of a large hand ])um]) with two hori- 

 zontal cylinders mounted on a 2()()-gallon tank, and two leads of 

 hose mth 15-foot extension rods, with double Vermorel nozzles. 

 A platform elevated about 4 feet over the rear end of the tank proved 

 very advantageous, especially for the first application, as it enabled 



