164 HATCH EXPERIMENT STATION. [Jan. 



annual gro^vth has been much more vigorous, and the health 

 of the trees has been much better. More and stronger fruit 

 buds have been formed, but unfortunately, the successive 

 freezes of the last tAvo winters have killed the buds, and made 

 a comparison of fruit crops impossible. The main branches 

 of the headed-back trees are shorter and stronger than those 

 of the unpruned trees, and are obviously better able to sup- 

 port a large crop of fruit. 



This experiment, which was begun b}^ Prof. S. T. May- 

 nard, and which has been continued through several years, 

 has shown conclusively that the best form of peach tree can- 

 not be secured and maintained without pruning. 



2. The Effect of Heading Back. 



Each spring, in the years 1902, 1903 and 1904, a number 

 of trees in the college peach orchards were headed back. 

 This shortening-in of the branches varied in amount : some- 

 times only one-third of the })revious year's growth was cut 

 aAvay, sometimes one-half the year's growth Avas taken off, 

 sometimes two-thirds was removed ; in a few cases the trees 

 were pruned clear back into two or three year old wood ; in 

 the majority of cases the heading-in amounted to about two- 

 thirds of the previous year's growth. The cutting back in 

 1903 and in 1904 was more severe than it would have been 

 had not the prospective fruit crop been wiped out by 

 freezing. 



In nearly all cases it was possible to compare trees thus 

 headed in with other trees of the same varieties not so treated. 

 The results were uniform and unequivocal. The trees 

 headed back alwa3\s made a more healthy and vigorous an- 

 nual growth than the trees not so treated. In many cases 

 the difference was remarkable, the growth of the pruned trees 

 being from two to ten times as much as the unpruned trees. 

 More and larger fruit buds formed on the pruned trees, and 

 the shorter, stockier branches seemed better prepared to suj:)- 

 port a possible fruit crop. The foliage on the pruned trees 

 Avas notably larger, more abundant and darker green. There 

 was some tendency to the formation of weak shoots on the 

 shaded interior branches. 



