12 



N. H. Agricultural Experiment Station [Bulletin 257 



for securing the surface area of a cone.^ These data were then 

 plotted on a scatter diagram by ages and sizes. Again a curve was 

 fitted by the use of the modified Reed and Holland formula ; for it was 

 thought that the growth of the apple tree would closely follow the 

 law of growth as determined for other types of plants. This 



growth 



lt> 



20 



?5 



30 

 Act 



3b 

 Years 



40 



4& 



50 



55 



M 



65 



Fig. 3. Mature tree equivalent or mature tree unit 



The actual size of trees of different ages as compared to a mature tree in its 

 .prime is indicated. ' This curve was obtained by fitting a growth curve to 

 measurements of trees of different ages. The calculated curve (dotted line) 

 was used except for old trees, some of which die and some of which lose 

 branches resulting in a decline in average size (solid line). 



I 



Table 2 — Acttial and expected normal yield on each orchard for three years. 



iThe area of the outer surface of the cone seems to be a better measure of 

 comparative size than the volume because in old trees the center contains 

 little or no fruiting wood. 



