11)05.] PUBLIC DOCUMENT — No. 33. I(i5 



The conclusion which we have reached from this experi- 

 ment, continued through three years, is that the heading 

 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 })revious year should be removed. 

 In determining the exact amount to be cut away, the judg- 

 ment of the fruit grower will be influenced largely by the 

 number of living fruit buds in the one-year-old wood. If 

 there is a crop in prospect, he will leave enough fruit buds 

 to set the desired quantity of fruit. In years when, from 

 one cause or another, there are no living fruit buds, he will 

 take advantage of the circumstances to cut back with com- 

 parative severity. Only in extraordinary instances, how- 

 ever, will he remove all the previous year's wood, cutting 

 back into two or three year old branches. 



o. Summer Pruning. 



It has been noted above that trees which were headed back 

 in the early spring pruning showed a tendency toward the 

 formation of many weak and useless shoots on the interior 

 of the head. Experiments in summer pruning were l)egun 

 with a view to the correction of this tendency, and also with 

 a view to stopping the really inordinate extension of the 

 main annual shoots of the current year. The two problems, 

 however, were met in different ways. 



The formation of weak sprouts on the interior of the tree 

 is due chiefly to the exclusion of light. The external foliage 

 of the tree top becomes so dense that the interior is shut off 

 from the light and from much of the air. To improve the 

 situation in this respect we have gone through the orchard 

 once or twice between the middle of June and the middle 

 of Jul}', removing a considerable quantity of the new leafy 

 shoots on the outside of the tree. A quantity of the out- 

 side shoots and foliaofe was thus removed sufficient to admit 

 a reasonable amount of light to the inside of the tree top. 

 The work Avas done with a i)air of hand pruning shears, or, 

 when the branches were soft, they were simply torn out 

 with the bare hands. The latter method is preferable, be- 

 cause more expeditious. 



