410 



FUNDAMENTALS OF FRUIT PRODUCTION 



Table 3. — Increase in Trunk Circumference under Varying Pruning 



Treatments 

 {After Tufts''') 



Kind of fruit 



Pruned 



severely 



(centimeters) 



Pruned • 

 moderately 

 (centimeters) 



Pruned 



lightly 



(centimeters) 



Apricot (Royal) . . . 

 Cherry (Napoleon) 

 Peach (Elberta) . . . 

 Pear (Bartlett) . . . . 

 Plum (Climax) . . . . 



Plum (Pond) 



Prune (French) ... 



Average 



11.7 

 10.0 

 12.0 



8.7 

 6.3 

 7.2 

 6.2 



8.9 



12.6 

 11.2 

 16.9 

 9.1 

 10.4 

 8.8 

 7.1 



10.9 



15.3 



12.3 



19.4 



9.7 



11.3 



9.4 



8.4 



12.3 



Amount and Character of New Shoot Growth. — The framework of the 

 tree is developed from its shoots of the preceding or earlier years. Since 

 the general influence of pruning is to check increase in size, it might be 

 reasoned that it results in a corresponding decrease in the amount of new 

 shoot growth produced each year. On the other hand it is possible that 

 the check to increase in size might be due largely, or even entirely, to the 

 annual removal of wood. Experimental data on this question were 

 obtained by Bedford and Pickering.^ They selected a number of shoots 

 in a tree, all as nearly as possible of uniform length (about 36 inches) and 

 thickness. Some were pruned back to a length of 6 inches, some to 

 12 inches, some to 24 and some had only their terminal buds removed. 

 Table 4 shows the relative numbers, lengths and weights of the new side 

 shoots that were formed and also the influence of these treatments on the 

 parent branch. Heavy pruning back resulted in fewer side shoots with 

 less total length and less weight than lighter pruning or than none at 

 all. The greatest decrease was in the number of new shoots, from 

 which it may be inferred that individually these shoots were somewhat 

 longer and stronger than those on the lighter pruned limbs. The differ- 



Table 4. — Effects of Pruning Back Individual Shoots Varying Amounts 

 (After Bedford and Pickering'^) 



Length of shoot after pruning, in inches 6 12 24 36 



Weight of original shoot and laterals (relative) 100 179 310 562 



Thickening of the original shoot (relative) 100 114 117 129 



New shoots formed: 



Number (relative) 100 116 198 292 



Length (relative) 100 113 145 183 



Weight (relative) 100 108 123 142 



ence in weight of old wood after a year's growth is particularly striking, 

 the unpruned trees having over five times the amount of those pruned 



