WINTER INJURY IN RELATION TO SPECIFIC FRUITS 327 



is recommended and that recommendation is confined to one district. 

 For the same districts 13 varieties of Duke and Morello cherries are 

 recommended. ^^^ Of 26 varieties in the catalog, 13 are recommended 

 for District 1 and of these, 10 evidently are considered worth growing in 

 District 2 which includes most of the northeastern fruit growing sections. 

 The three leading commercial varieties, Early Richmond, Montmorency 

 and English Morello, are considerably hardier than the Baldwin apple. 

 However, some of the hardiest apples appear to be hardier than the hard- 

 iest cherries. Hansen*^ states that root killing is the one great difficulty 

 in cherry growing in South Dakota. Following the February, 1899, freeze, 

 with a minimum of -27.5°F., at Madison, Wis., some root killing was rep- 

 orted, but most varieties brought their fruit buds through, Large Morello, 

 Late Morello, Shadow Amarelle, Dyehouse and Ostheim having over 

 90 per cent, live buds.^^ Curiously enough many varieties undamaged 

 in the 1899 freeze had their buds killed in the winter of 1896-1897 with a 

 minimum of — 23°F. During the summer of 1896 the trees had been in 

 sod and there was much dry weather. Considerable variation in the 

 hardiness of the embryo flowers, not alone between varieties, but on the 

 same tree and even within the same bud, has been reported. ^^ Careful 

 study showed a strong inclination toward tenderness in varieties having 

 the greater number of flowers per bud and a similar susceptibility in 

 individual buds within the variety. The periphery of the tree had 39.9 

 per cent, live buds while the central part had 69.9 per cent, alive. Goff 

 did not regard this difference as due alone to the greater number of flowers 

 in the peripheral buds but suggested that it might be due to the protection 

 afforded by the branches and to conduction of heat along the trunk from 

 the soil. Roberts, ^^^ also working in Wisconsin, reported that though 

 winter injury to cherry buds is frequent in that state, it is rarely severe 

 enough to affect seriously the yield of fruit. Frequently only one or two 

 of the four or five blossoms within the bud are killed. Studies made in 

 the spring of 1917 are interesting in several respects. All injury had been 

 confined to blossom buds. Older trees showed more injury than young 

 and the exposure appeared to have little relation to the amount of injury 

 during that winter. Trees which had been partly defoliated by the shot 

 hole fungus the previous season received less bud injury than normal trees. 

 The shortest and the longest spurs were less injured than spurs of medium 

 length and on terminal shoots there was less injury in the buds at the 

 base and at the tip than along the central portion of the shoot. Larger 

 buds were most frequently injured. 



The injury occurred early in December following a temperature of 

 -12°F. and could not have been due to development excited by warm 

 winter weather. Microscopic study showed that the buds most 

 damaged were the most advanced in their development. Late maturity 

 could not have been the factor involved as the trees and parts of trees 



