278 Missouri Agr. Exp. Sta. Research Bulletin No. 8 



During the season of 1908 this study was continued and we 

 have the results for the freeze of January 12, 1909, where the kilHng 

 was not caused by cold periods following warm periods, but by cold 

 periods when the buds were fully dormant. In this case there was 

 no difference in the hardiness due to thinning, as the following table 

 shows : 



Table 45. Showing the Percentage of Buds Killed on 

 Thinned and Unthinned Limbs of Trees When the Buds Had 

 Not Been Started into Growth Before the Freeze. 



During the same season artificial freezings of buds from the 

 thinned and unthinned sides of these trees were run, and in this also 

 there was no constant difference between the percentage of buds 

 killed from thinned and unthinned limbs. These results suggest 

 that thinning has its effect on the rest period rather than on the in- 

 trinsic hardiness of the buds. Where the tree is bent under a heavy 

 load and under the strain of bearing a heavy crop, as when it is not 

 thinned, the moisture supply probably being partially shut off, the 

 same condition will prevail, at least to some extent, as when the trees 

 are not cultivated; they will become dormant earlier and end their 

 rest period earlier. Thus thinning, like heavy pruning and fertiliz- 

 ing with nitrogen can be expected to increase the hardiness of peach 



