46 Fruit-growing in Arid Regions 



be added to the border, and we should hardly notice that 

 the trees were any closer together. 



A simple method of determining the number of trees 

 required to plant an acre, when planted by the square 

 or rectangular plan, is to multiply together the two dis- 

 tances, in feet, at which the trees stand, and divide 43,560 

 (the number of square feet in an acre) by the product. 

 To find the number required for the hexagonal system, 

 add 15 per cent to the number required to set at the 

 same distance with the rectangular system. 



Fillers 



The advisibility of planting "fillers" (or temporary 

 trees between the others, to be removed as the others 

 mature) in the apple orchard has been argued pro and 

 con, and it probably always will be a debatable question, 

 for much depends on the man who grows the orchard. 

 The only objection the writers have to planting fillers 

 is that they too often become fixtures. The average 

 man lacks the courage to pull out a tree when it gives 

 promise of producing another crop, and, as a consequence, 

 the shape of the permanent tree is ruined before the filler 

 is removed. If we were planting an orchard, we would 

 probably plant fillers, but at the same time we could not 

 advise every one to follow our example. 



If properly selected and removed in time, fillers are 

 profitable. Peach trees as fillers are probably as profit- 

 able as any in a section where a peach crop can be 

 relied on, and, if properly handled, they should produce 

 a box of fruit the third season with an increase of two to 

 three boxes per season for the next three years, or until it 



