8 



BULLETIN 959, U. S. DEPARTMENT OF AGRICULTURE. 



In the Johnson orchard the principal part of the experimental 

 work was a test of the efficiency of coarse sprays applied with a short 

 rod and Bordeaux nozzle in comparison with mist sprays applied by 

 means of spray poles equipped with whirlpool-disk nozzles. 



The short rod referred to consisted of a piece of iron pipe about 

 1 foot in length, to one end of which was attached a Bordeaux nozzle 

 and to the other a cut-off to which the hose was connected. Under 

 a pressure of 225 to 250 pounds and with the nozzle sufficiently open, 

 the spray was practically a solid stream as it left the nozzle, but 

 broke up more or less as it reached the tree. This type of spraying 

 apparatus had been used by many Grand Valley growers for several 

 seasons in preference to the spray poles, formerly employed, because 

 it rendered spraying less burdensome and increased the speed of the 

 work. The spray gun, which was subsequently developed, is an 

 improvement over the short rod, in that the character of the spray 

 can be readily graduated from fine to coarse. 



The spray history of the experiments in the Johnson orchard will 

 be found in Tables 5 and 6. 



Table 5. — Spraying schedule for the codling moth, Johnson orchard, Grand Valley of 



Colorado, 1976. 





Calyx 

 spray. 



Cover sprays— first brood. 



Cover sprays — second 

 and third broods. 



Number of plat. 



A. 



B. 



C. 



D. 



E. 



F. 



G. 





Petals off, 

 May 2-3. 



3 to 4 

 weeks 

 after A, 

 May 29. 



14 days 

 after B, 

 June 12. 



18 days 

 after B, 

 June 16. 



14 days 

 after C, 

 June 26. 



9 to 10 



weeks 

 after A, 

 Julys. 



34 to 41 



days 



after F, 



Aug. 11-18. 



I 



First 



...do 



...do 



Second 



...do.... 



Third 





Fourth.... 

 do .. 



Fifth 



.. do 



Sixth. 



n 



.. do.... 





Do. 



ni 



...do 





Third 





Fourth.... 

 do . - 



Fifth. 



IV 



do.-.. 



. do... 





dn 





Do. 



v 



...do 



...do 







Third 



(\r, 



Fourth. 



VI 



...do 



...do 







Do. 



VII 



Check 







1 











1 



1 





Table 6. 



-Treatment of plats for the codling moth, Johnson orchard. Grand Valley of 

 Colorado, 1916. 



Num- 

 ber of 

 plat. 



Spraying materials. 



Spraying equipment. 



Calyx spray. 



Cover sprays. 



I 



II 



Arsenate of lead, powder, 



1 pound— 50. 

 do 



Spray poles and Bordeaux 



nozzles. 

 Short rod andBordeaux nozzle 

 Spray poles and Bordeaux 



nozzles. 

 Short rod and Bordeaux nozzle 

 Spray poles and Bordeaux 



nozzles. 

 Short rod and Bordeaux nozzle 



Spray poles and whirlpool-disk 

 nozzles. 



III..... 



do 



Spray poles and whirlpool-disk 



nozzles. 

 Short rod and Bordeaux nozzle. 



IV 



. ...do.... 



V 



do 



Spray poles and whirpool-disk 

 nozzles. 



VI 



do 



VII 



Check — unsprayed 













