COST OP PRODUCING APPLES IN YAKIMA VALLEY. 47 



Sixth lead-arsenate spray. — The sixth lead-arsenate spray, usually 

 applied during the latter part of August or the first of September, 

 depending upon the season, was made by 8 per cent of the growers 

 considered in this study. Because so few of the orchardists in the 

 valley made this spray, the comparison of the figures in Table XXXIV 

 should not ordinarily be made. It was necessary, however, to use 

 them in order to arrive at the total cost of spraying for these 120 rec- 

 ords. In considering all records for the valley, whatever the size 

 of crew, and whether the spray outfit is owned or hired, the total 

 labor and material cost for the sixth lead-arsenate spray was $0.29, 

 or 1.15 per cent of the total labor and material spraying cost. (See 

 Table XXXVI.) 



SUMMARY OF SPRAYING PRACTICES. 



There is a tendency in the valley to make a more thorough applica- 

 tion of material on orchards under clean-cultural management than 

 on those under mulch-crop management. Where owned outfits are 

 used on such orchards, more material is applied per acre, fewer acres 

 are sprayed per day, and the average total labor and material cost is 

 greater than where owned outfits are used on mulch-crop orchards. 

 However, where hired outfits are used on orchards under clean-cul- 

 tural management less material is applied, more acres are sprayed 

 per day, and the total labor and material cost is less per acre than 

 where such outfits are used on orchards under mulch-crop manage- 

 ment. As results from the owned outfits are better as a basis for 

 comparison, it would seem that orchards under clean-cultural manage- 

 ment received a more thorough application of spray material. This 

 is brought out more clearly by making a comparison of all orchards 

 where spraying is done with owned outfits with those where hired out- 

 fits are used. (See Table XXXIV.) 



It is found that for practically all the orchards studied more acres 

 are sprayed per day with a hired outfit, less material is applied per 

 acre, and the total labor cost is less than where the outfit is owned. 

 Comparing the North Yakima and the Zillah districts, it is found that 

 with owned outfits more acres are sprayed in 10 hours and more mate- 

 rial is applied per acre and per tree in the Zillah district. Consider- 

 ing the 120 orchards, the average cost for spraying labor and 

 material is $0.0256 more per box than in the North Yakima district. 

 The pro rata labor cost for spraying, considering all records for the 

 valley, was $12.93, and the material pro rata cost was $12.21 per 

 acre, making a total of $25.14 per acre, or $0.0582 per box. (See 

 Table XXXV.) 



13116°— 17— Bull. 614 4 



