PRUNING—THE METHOD 437 



the degree of starvation of the roots through separation from their supply 

 of elaborated foods and its ultimate effect on growth and development is 

 in every way comparable to the results attending root pruning. It 

 should be mentioned also that ringing inflicts mechanical injuries that 

 sometimes heal slowly and for this reason alone it should be used with 

 great caution, if at all, on certain fruits like the plum and cherry. Appar- 

 ently with the grape alone, among the connnon deciduous fruits, should 

 this group of practices be a regular cultural treatment and even in the 

 grape only a very few of the most vigorously growing varieties can be 

 ringed with profit. Other cultural treatments may be combined and 

 employed to better advantage to bring about the same conditions that 

 these special practices induce and with far less danger of undesirable 

 after-effects. 



Summary. — In kind all top pruning may be considered either as 

 heading back or as thinning out. These two kinds produce quite differ- 

 ent results, particularly as the pruning increases in severity. In general, 

 thinning out is accompanied by less new shoot growth but more new spur 

 and fruit-bud formation than correspondingly severe heading back. 

 Heading back tends to make trees more, and thinning out less, compact 

 in habit. The different responses from the two methods of pruning are 

 due probably in large part to the distinct nutritive conditions to which 

 the practices give rise. Both methods have their places in orchard man- 

 agement, heading l)ack being more viseful in keeping the tree well shaped 

 and thinning out in developing its fruiting wood and in keeping that wood 

 in good working order. As most trees grow older they should receive 

 relatively more thinning out and less heading back. 



In kind, pruning may be coarse or fine with essential differences 

 in the attendant responses. Coarse or bulk pruning tends to disturb 

 seriously the equilibrium within the plant and generally results in the 

 production of watersprouts. Careful fine pruning, on the other hand, 

 evokes a much more general response. The ideal pruning is fine, as 

 opposed to coarse or bulk; however in practice a compromise must gen- 

 erally be made between the kind which is best for the tree and the kind 

 which is most economical. 



Root pruning has a dwarfing influence and its greatest use is in the 

 culture of dwarf trees. The supposed influence of root pruning in pro- 

 moting fruitfulness is due probably in part, if not largely, to other prac- 

 tices such as irrigation and fertilization which generally accompany the 

 culture of dwarfs. 



Girdling, notching, ringing and stripping are special practices, related 

 to pruning, which have for their object the promotion of fruitfulness 

 through interrupting the translocation of foods. Their use is attended 

 by uncertain results and they are not to be recommended under average 

 conditions. 



