-2- 



too small for the job or to failure to make the most efficient use of it. 

 Factors which affect the size and efficiency of a sprayer are suggested in 

 the following table; 



2 3 4 5 



Number of trees 

 Age of trees 

 Height of trees (ft.) 

 Spread of trees (ft.) 

 Gallons per tree 

 Total gallons 

 Hours per day 

 Output per minute 

 Size of pump 



(gals . per min.) 

 Tank size (gals.) 

 Min. to unload 

 Min. to reload 

 Total time per load(min,) 

 Number leads per day 

 Total gals, per day 

 Days to cover orchard 



In this table it is necessary to make certain assumptions. Let us 

 assume that the orchard contains 1,000 mature trees v/hich on the average will 

 require 15 gals, eaoh to obtain adequate coveragOo (The number of gallons 

 of spray required for trees of various ages and sizes is indicated in a table 

 which is published as a part of the "Spray Chart for Apples" as well as in 

 Mass. Ext. Leaflet 178.) Thus, a total of 15,000 gallons of spray will be 

 required to cover the orchard. 



In Column 1 it is assvimed that the discharge from the nozzles is 15 

 gals, per min. Thus, a 300 gal. tank could be emptied in 20 minutes. Allow- 

 ing for interruptions, it is assumed that it would take 25 minutes to unload. 

 V/ith such a piece of equipment operating 10 hours per day it would require 

 3.8 days to cover the orchard. Obviously this equipment is too small for tho 

 job. In Column 2 let us assume that the output, by the addition of more noz- 

 zles, can be increased to 20 gals, per min. The time required to cover the 

 orchard will be reduced to 3.3 days, but still the equipment is too small. 



In Column 3 let us assume that the tank is increased from 300 to 400 

 gals. This will help somewhat but not enough. In Column 4 let us assume 

 that it requires only iO minutes to reload instead of 25 minutes. Then, with 

 the same equipment as before, the orchard can be covBred in 2«2 days. Even 

 working 8 hours per day a-5 indicated in Column 5^ the orchard can be covered 

 in less than 3 days pjovided it takes only 10 minutes to reload. 



It is fully recognized that in this table many assumptions have been 

 made and no allowance has been provided for delays due to weather and other 

 caus«5. The two blsjik coluinns have been provided for the ucie of anyone who 

 •wishes to do so to fill in the actual conditions which exist in his ovm or- 

 chard or orchard.-; and hh'is datorrriineto what =jxt«i.t hir present equipment is 

 adequate to do the job. 



