Killing of Plant Tissue by Low Temperature 



275 



Thus 18.1 per cent of the buds on these cut back trees were still 

 alive after the two freezes. These trees set practically a full crop 

 while trees around them bore not more than one or two peaches to the 

 tree. On the same year, trees heavily pruned the previous spring at 

 Doniphan, Missouri (another southern county), were more than 

 three weeks later in blooming than trees not so treated, as reported 

 by Mr. J. R. Stevens. 



The rest period can also be as readily prolonged by fertilizing 

 with a nitrogenous fertilizer, thus prolonging the growth into the 

 fall. In the Brandsville orchard mentioned above, in 1910 a plot 

 of trees was heavily fertilized with ammonium sulphate. One plot 

 of thirty trees received 100 pounds and another plot of sixty trees 

 received 100 pounds. The following table gives the percentage 

 of buds killed on those trees receiving the heavy applications of 

 fertilizer on February 22 and on March 16, and also the percentage 

 killed on adjoining trees not so treated, and on trees fertilized lightly 

 with sodium nitrate in 1909 and in 1910: 



Table 43. Showing the Percentage of Buds Killed at Brands- 

 ville, Missouri, by the Freezes of February 22 

 AND March 16, 1911, on Trees Fertilized 

 With Nitrogen and Trees 

 Not so Fertilized. 



On the trees fertilized heavily the spring before with ammonium 

 sulphate a percentage of buds large enough for a full crop was left 

 after both of these freezes, and the trees set and ripened a full crop 

 of fruit, while the adjoining trees had nothing. Trees fertilized with 

 sodium n.itrate, but not so heavily, did not show such marked results, 

 and yet there were enough buds left for a fair crop, if all the orchard 



