PRUNING BEARING APPLE TREES 7 



Effect of Pruning on Growth 



Annual measurements of trunk growth have been made on three of the orchards 

 under consideration. Table 1 gives the average increases in trunk diameter of 

 the trees in Block A from 1924 to 1930. 



Table 1. — The effect of pruning on increase in trunk diameter- 

 1924 to 1930, inclusive. 

 (Millimeters) 



-Block A, 



The three groups of trees not headed back were removed in 1930, and three 

 groups, including the unpruned trees, remain. Table 2 shows the growth of these 

 trees for the period from 1924 to 1933. 



Table 2. — The effect of pruning on increase in trunk diameter — Block A, 



1924 to 1933, inclusive. 



(Millimeters) 



Study of Tables 1 and 2 fails to reveal any evidence that the uniform moderate 

 pruning given these trees since 1924 has consistently decreased trunk growth. 



Annual measurements have been made of the Wealthy trees in Block K. 

 Table 3 shows the increase in trunk diameter made by these trees during the 

 period 1921 to 1932. 



This table shows no dwarfing effect of pruning. The lightly pruned trees seem 

 to have made a little more growth, as measured by trunk diameter, than the 

 unpruned trees, also the moderately pruned trees show slightly more growth. 

 This suggests that with these trees pruning has had a slight invigorating influence. 

 It would have been possible to increase growth of these trees by different soil 

 management or more fertilizer and this would have been a more rational practice. 

 This was not done for reasons not concerned with this experiment. If the rows 

 are considered in alphabetical order as they stand in the orchard there will be 

 revealed a progressive decrease in growth from Row D to Row O. These rows 



