30 



BULLETIN 500, U. S. DEPARTMENT OF AGRICULTURE. 



Table XVIII. — Cost of operation for S-men, 2-horse spraying creic. 



Spray. 



Number 



of 

 records. 



Normal 

 time. 



per 

 da v. 



per 

 acre. 



Labor 

 I cost 



tree ^ 

 iree - acre. 



Mate- 

 rial 

 cost 

 per 

 acre. 



Lime and sulphur spray 



First lead arsenate spray 



Second lead arsenate spray. . . 



Third lead arsenate spray'. 



Fourth lead arsenate spray. . . 

 Fifth lead arsenate spray.*. . . . 

 Sixth lead arsenate spray 



All lead arsenate sprays 



6.8 



35S 



3.8 



ri l 



2.07 



Total 

 cost 

 per 



acre. 



5.1 S2.38 ! SS.23 S10.61 



90 1 



7. SI 



3.8 



519 1 



7.1 



2.73 



2.15 



4.S8 



87 



7.62 



3.9 



462 | 



6.3 



2.67 



1.91 I 



4.58 



74 



7.62 



3.9 



4-0 



6.6 



2.67 



1.98 



4.65 



50 



7.83 



3.8 



514 



7.1 



2.74 



2.05 1 



4.79 



33 



7.81 



3.8 



542 1 



7.6 



2.73 



2.17 



4.90 



17 



7.98 



3.8 



585 



8.4 



2.79 



2.34 ' 



5.13 



4.78 



Table XIX. — Cost of operation for 2-men, 2-horse spraying crew 



Spray. 



Mate- 

 Number'.- , Acres Gallons Gallons L n a ^° r rial T n °*? 



of ■ t?m? P er 1 P er P er oer cost 2? 

 records. ■ day. acre. tree. **£ | per *** 



! acre - acre. acre - 





4 6.14 3.3 



324 4.6 S2.46 1 S7.45 S9.91 







First lead arsenate sprav 



23 6.21 

 26 5.53 

 23 5.60 

 17 5.38 

 12 5.27 

 5 4.97 



3.2 

 3.6 

 3.6 

 3.7 

 3.S 

 4.0 



550 

 458 

 446 

 490 

 531 

 532 



7.4 

 6.2 

 6.0 

 6.6 

 7.2 

 7.6 



2.4S 

 2.21 

 2.24 

 2.15 

 2.11 

 1.99 



2. 27 4. 75 



Second lead arsenate spray 



Third lead arsenate spray'. 



Fourth lead arsenate spray 



Fifth lead arsenate spray 



Sixth lead arsenate spray 



1.89 



1.84 

 1.96 

 2.12 

 2.13 



4.10 

 4.08 

 4.11 

 4.23 



4.12 



All lead arsenate sprays 



106 5. 61 



3-6 



491 



6.6 



2.24 



2.03 



4.27 



Table XX. — Summary of comparative efficiency data for spraying crews. 



Number 



Crew. of sprays 



; studied. 



Normal 

 time man- 

 hours. 



Cost per acre. 

 Acres per Gallons Gallons 

 day. per acre, per tree. 



Labor. Material. 



Total. 



3-2... 

 2-2... 



' 351 



106 



7.73 

 5.61 



3. 8 501 6. 8 2. 71 2. 07 

 3.6 491 6.6 2.24 , 2.03 j 



-54. 7S 

 4.27 



LIME-SULPHUR SPRAT. 



The lime and sulphur is applied during the dormant season, usually 

 during February or March, and is applied primarily for the San Jose 

 scale, and, as the growers express it, to ''clean up the trees.'' As 

 stated above, comparatively few growers were using this spray when 

 the records here presented were obtained. The average solution 

 used is 1 to 10; that is, 20 gallons of hme-sulphur and 200 gallons of 

 water. 



APHIS SPRAYS. 



Another spray sometimes applied separately, but usually in con- 

 junction with one of the lead arsenate sprays, is the aphis spray. In 

 Mesa County on the farms studied there was no record of the use of 



