WINTER INJURY 



255 



has been reported by Whipple ^ as occurring in Montana. In 

 such cases, the axiUaiy leaf-bud will continue the growth 

 of the spur and, before the growing season is over, it is diffi- 

 cult to observe that flower-buds had been formed. 



Like the apple, the fruit-buds of the pear are not likely 

 to be injured, but the spur itself may be killed with the con- 

 sequent destruction of the fruit-bud. 



As a rule, the more commonly grown varieties of the sour 

 cheriy are hardy in buds as far north as central New Eng- 

 land, except in veiy extreme win- 

 ters or when low temperatures 

 follow after the buds have swollen. 

 On the other hand, Macoun - re- 

 ports that in the fruit-growing 

 sections of Canada the cherry, 

 like the European and Japanese 

 plums, is injured more or less 

 eveiy winter when not protected 

 1)}' some body of water. Similar 

 injuiy to the buds of early Rich- 

 mond cherries was reported in 

 Wisconsin after the winter of 

 1917-18.3 (Fig. 34). 



The sweet cherry is much less 

 reliable than the sour cherry; in 

 fact it is not much more hardy 

 than the peach. 



Varieties of the plum vary widely in their hardiness. 

 Many of the American species (such as Prunus nigra) are 

 very hardy, while others are not. Some varieties of P. 

 salicina, such as the Burbank, also are reasonably hardy 



1 ^\^lipple, O. B. Mont. Agr. Exp. Sta. Bull. 91. 1912. 



2 Canada Exp. Farm, Kept. 1907-08. pp. 110-116. 

 ' Proc. Soc. Hort. Sci. 15th Kept. 1918. p. 32. 



Fig. 34. — Fruit-bud of sour 

 cherry. Left, flower-bud 

 alive; right, flower-bud 

 killed. 



