THE GROWING OF THE FRUIT PLANTS 413 



to save the vitality of the tree; to enable one to combat insects 

 and diseases by destroying the injured fruit. 



The thinning is nearly always performed soon after the fruit 

 is thoroughly set. It is then possible to determine which of the 

 fruits are likely to persist. Peaches are usually thinned when 

 they are the size of one's thumb. If thinned before this time, 

 they are so small that it is difficult to pick them off; and 

 it is not so easy to see the work of the curculio and thereby to 

 select the injured fruits. Similar remarks apply to other fruits. 

 The general tendency is, even with those who thin their 

 fruits, not to thin enough. It is usually safer to take off 

 what would seem to be too many than not to take off enough. 

 The remaining specimens are better. Varieties that tend to 

 overbear profit very greatlj^ by thinning.' This is notably the 

 case with many Japanese plums, which, if not thinned, are 

 very inferior. 



Thinning may also be accomplished by pruning. Cutting 

 off the fruit-buds will have the effect of removing the fruit. In 

 the case of tender fruits, as peaches, however, it may not be 

 advisable to thin very heavily by means of pruning, since the 

 fruit may be still further thinned by the remaining days of win- 

 ter, by late spring frost, or by the leaf-curl or other disease. 

 However, the proper pruning of a peach tree in winter is, in 

 part, a thinning of the fruit. The peach is borne on the wood of 

 the previous season's growth. The best fruits are to be expected 

 on the strongest and heaviest growth. It is the practice of 

 peach-growers to remove all the weak and immature wood from 

 the inside of the tree. This has the effect of thinning out the 

 inferior fruit and allowing the energy of the tree to be expended 

 on the remainder. 



Apples are rarely thinned; but, in many cases, thinning can 

 be done with profit. 



