238 



TRlNCirLES AND PRACTICE OF PRUNING 



(luring winter. Such pruning aids in tliinning the fruit 

 (KJli), liut (Iocs not wholly ol)\'iatc summer thinning. 

 Alwa}'s the aim should be to keep the trees hnv-headed, 

 so as much fruit as possible may be gathered without the 

 aid of ladders, and when ladders arc used at all they 

 should be not more than tJ feet high. 



202. Pruning vs. p=ach bud vigor.— W. H. Chandler* experimented 

 witli peacli trees to determine the effect of pruning and trimming 

 upon bud \'igor. His main conclusions follow: 



In Missouri nearly every winter warm weather starts the buds 

 into growth more or less, b'ruit buds on trees that have made a 

 vigorous growth, caused by reasonably 

 se\ere heading back or by cultivation, are 

 the less liable to winter injury. Heading 

 back may lie too se\'erc, however, since 

 in any year the fruit buds most likely to 

 coinc through the winter safely are those 

 at the base of the whijis of new wood. If 

 the heading back has been too severe, the 

 growth will be so dense that no fruit buds 

 will be formed at the base of those whips. 

 In the experiment station orchard the 

 trees havin,g the smallest percentage of 

 buds killed were those trained to a 

 spreading, open head, and forced by prun- 

 ing and cultivation to make a vigorous 

 growth. 



The fruit on trees with spreading heads 

 does not rot so badly as that on trees with 

 dense heads. The fruit on trees making 

 a \'igor('us growth, unless the growth is 

 too vigorous, is larger than that on trees 

 making smaller growth. This is true e.x- 

 whcre a tree making a rather small wood 



HG. 220— PROPERLY CUT 



BACK PEACH 



This five-year tree had 



been severely winter injured. 



It was saved by radical eut- 



cept with early varieties, 

 growth bears the better fruit. 



Thinning the fruit enables the tree to set more hardy fruit buds 

 for the next crop [than wdiere it is not practiced]. In the station 

 orchard a tetnperature of (i degrees below zero one winter killed 

 from 5 to 40 per cent more buds on the unthinned side of a tree 

 than on the thinned side. 



In experiments conducted by F. A. Waugh in Massachusetts, 

 jicach trees left unpruned for nine years became open headed and 

 of vase form, but the lower parts of the branches were liare and 

 the fruiting wood sparse, weak and lii.gh up in the trees. The trees 

 were also much less vigorous than pruned trees of the same variety; 



-A^.issouri E.xpcriment Station Bulletin 74. 



