248 



EXPERIMENT STATION RECORD. 



pruned trees of the same variety. As a result of this lack of vigor a number of trees 

 succumbed to the cold during the preceding winter. 



A row of trees next to this has been headed back moderately 2 or 3 times, as a 

 result of which they are thick topped, with a good deal of weak, sappy growth on the 

 inside. The annual growth, however, has been much more vigorous and the health 

 of the trees better than those not pruned. More and stronger fruit buds have also 

 formed. The main fruit branches are shorter and stronger and more capable of sus- 

 taining a large crop of fruit. The experiment is believed to show conclusively that 

 the best form of peach tree can not be secured and maintained without pruning. 



During the past 3 years a special experiment has been made in heading back peach 

 trees in the spring. The conclusion reached relative to this work is that "the head- 

 ing back of peach trees in early spring is good practice and in all cases advisable. 

 In this pruning from one-third to two-thirds of the wood of the previous year should 

 be removed," depending upon the number of living fruit buds on the 1-year-old 

 wood. When from any cause there are no fruit buds advantage should be taken to 

 cut back with comparative severity- Only in extraordinary instances, however, 

 should the cutting extend back into 2 or 3 year old branches. 



Some experiments were made in summer pruning peach trees. With early spring 

 pruning it had been noticed that many weak and useless shoots grew in the center 

 of the tree. It was thought that if a considerable quantity of the new leafy shoots 

 on the outside of the tree were removed, thus admitting a reasonable amount of light 

 to the inside of the tree top, some benefit might result. 



" In no case were the results of this treatment convincing. The formation of strong 

 shoots with fruit buds on the interior branches was never visibly promoted. The 

 outside branches w T hich were allowed to remain seemed to profit somewhat by the 

 removal of their crowding neighbors, and this was apparently the chief benefit 

 derived from the work. On the whole, it does not seem to us that this practice is to 

 be greatly recommended." 



Cutting back the young growth of the outside branches to correct overgrowth did 

 not give satisfactory results. The stopping of the growing shoots was usually followed 

 by the pushing out of side buds and shoots lower down which were nearly always 

 too weak to set good fruit buds. 



Considerable winter injury was sustained by peach trees in both 1903 and 1904. 

 The damage was not serious in 1903, but in 1904 the trees were seriously weakened 

 by freezing, and some were killed outright. In treating the injured trees one block 

 was left entirely without pruning, another was pruned in midsummer after the trees 

 had started; a third was cut back from two-thirds to three-fourths of the previous 

 ^ear's growth, and a fourth was headed back near to the trunk, only the stubs of the 

 main branches being left. The following table shows the results: 



Effect of different methods of pruning frozen peach trees. 



Method of pruning. 



Trees un pruned 



Moderately cut back 

 Severely cut back . . . 

 Cut back to stubs . . . 



Living. 



Per cent. 

 93 

 99 

 81 

 52 



While a large number of the unpruned trees lived, the growth made by the 

 headed-in trees which lived was much better than that made by the unpruned 

 trees. It was the judgment of many who saw the trees that the trees moderately 

 cut back showed the best growth and were in the best condition. The experiment is 



