May, 1931] Studies in Economics of Apple Orcharding 



11 



Table 1 — Normal expected yield and mature tree equivalent at each age 

 during the life cycle of the apple tree. 



*Normal expected yield is the number of packed boxes of marketable fruit 

 which can be expected by an average orchardist on an average site. 



fMature tree equivalent refers to size of trees at different ages in terms of 

 a mature bearing tree at its prime. 



normal expected yield is satisfactory as a unit of comparison only in 

 orchards within a limited range in age; and the second unit '' mature 

 tree equivalent" was calculated, representing the comparative size or 

 total foliage at different ages, expressed on the basis of the size and 

 amount of foliage of a mature tree in its prime. One thousand mature 

 tree units would constitute an orchard of approximately forty acres, 

 trees set about 40 feet apart and all in their prime. 



Since there were no available data for comparison of size by ages, 

 380 trees of varying but known ages were measured on several dif- 

 ferent farms. From these measurements, the area of the outer sur- 

 face of the tree was calculated for each of the trees from the formula 



