164 



time, poor pollination, or other reasons, for injury from freezing. 

 It is certainly true that a poor set of fruit is often attributed to frosts 

 when a careful observation following the frost would have shown 

 that no bloom or fruits were killed. 



KILLING OF CHERRIES AND PLUMS 



Killing of various tissues of other fruits has not been extensively 

 studied at this Station, except as described in the early part of this 

 paper. As to killing of buds, Macoun 1 states that under Canadian 

 conditions, especially in the Province of Quebec when away from the 

 protection of a body of open water, European and Japanese plums, 

 and cherries are injured more or less every winter. He lists Mount 

 Royal and Raynes as new varieties very hardy in bud. Japanese 

 plum fruit buds have killed in Missouri only after cold -periods fol- 

 lowing sufficient warm weather to start them into growth. 



In case of killing by spring freezes, the Wild Goose plum is very 

 resistant to low temperature as will be seen by reference to Table 51. 

 On April 24, 1910, when all other fruits in the Station orchard, ex- 

 cept Ingram and Ralls apples which were just in bloom, were 

 killed by a temperature of 27° F. Wild Goose plums were uninjured 

 though they had reached a diameter of 3-16 of an inch. We are not 

 prepared to say, however, that the young fruit of the Wild Goose 

 plum is not more hardy than the bloom. 



In the case of cherries observations have been made on the kill- 

 ing of the Early Richmond cherry buds to a large extent, and other 

 varieties to a small extent, especially by cold periods following warm 

 weather. On January 7, 1912, the following percentages of fully 

 dormant cherry buds were killed by a temperature of -20° F. : Early 

 Richmond, of 200 buds counted, 52.5. per cent were killed; Mont- 

 morency, of 150 buds counted, 12 per cent were killed; Dyehouse, 

 of 175 buds counted, 11.4 per cent were killed. 



Macoun holds that fruit buds of cherry, peach and Japanese 

 and European plum kill more easily than do the buds of the apple 

 and the pear because they have less protection from evaporation. 

 Goff 2 found a larger percentage of cherry buds to survive a tempera- 

 ture of -273^° F. in Wisconsin in February, 1899, in the central por- 

 tion of the tree than on the ends of the outer branches. He concludes 

 that this results because those near the center of the tree were par- 

 tially protected from drying winds. It does not seem probable 



'Canada Exp. Farms, Bpt. 1907-8, pp. 110-16. (Bibl. No. 68). 

 "16th An. Ept. Wis. Agr. Exp. Sta. pp. 283-88. 1899. (BibliNo. 46). 



