104 



PRINCIPLES AND PRACTICE OF PRUNING 



erate dormant pruning stimulated a greater growth than any of 

 the summer prunings, and the reduction in vigor was less in the case 

 of early summer pruning than with either repeated summer or mid- 

 summer prunings. 



The foliage is a very good index of the vigor of a tree. A 

 careful study of leaf size, color and number was made in the Lup- 

 tm and the Grimes Golden orchards. In all cases the blocks that 



FIG. 73 



BADLY DEVELOPED TREE HEAD. TOO MANY LIMBS CLOSE TOGETHER 



Never allow a tree he-d to develop in this way. Such over-crowding can be prevented 



by correct, early pruning. It is difficult to remedy later. 



had received summer pruning bore a paler or yellower foliage than 

 those pruned in the dormant season. This difference in color was 

 so distinct that there could be no mistaking the summer-pruned 

 blocks even at a distance. 



It is clear I from the data secured] that summer pruning caused 

 a great decrease in the size of leaf, number of leaves to the tree 

 and in the total leaf area on the tree. If we further consider that 

 these leaves are deficient in chlorophyll, as evidenced bv their li^h* 



