32 N. H. AGR. EXPERIMENT STATION. [Bulletin 12 



SUMMARY. 



The relation of external factors to growth of a mature bearing 

 apple orchard seems to be quite complex and not easily analyzed. 

 Thus, trees may make a greater growth in a wet season than in a 

 very dry season but other competing factors may enter to a 

 sufficient degree to practically annul this fact. When the trees 

 are bearing an enormous crop of fruit the growth may be modified 

 even though growth conditions are favorable, and if the orchard 

 is severely pruned in the winter, the growth the following season 

 may be modified as a result. A change in cultural or fertilizer 

 treatment may also greatly modify the normal growth of the 

 trees. 



