68 



buds have been known to survive temperatures of -30° C. and lower, 

 and the tree will survive, under favorable conditions, considerably 

 lower temperature than that. In fact Macoun 1 cites an instance 

 where a Pyrus baccata — Pyrus Malus hybrid — has withstood for 

 five years a climate whose temperature frequently falls to -50° F., 

 and in 1909 it fell twice to -59° F. 



At the beginning of winter, as observed by the authors above, 

 the tree tissue generally — whether it is buds, wood, cambium or 

 cortex — will stand less cold than later in the winter. Observation 

 at this station indicates that at least some tissue increases in hardiness 

 rather rapidly for a short time following leaf fall. The following 

 table gives the temperature and result of freezing peach fruit buds, 

 beginning in summer when they are first plainly to be observed and 

 continuing until January: 



Table 22. Showing the Relative Hardiness of Fruit Buds at 

 Various Seasons of the Year. 



Kind of Buds 



Date 



Percent- 

 age 

 Killed 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Elberta peach buds 



Oldmixon peach buds. . . . 

 Oldmixon peach buds. . . . 

 Oldmixon peach buds. . . . 



Oldmixon peach buds 



Late Duchess apple buds 



Jonathan apple buds 



Jonathan apple buds 



Jonathan apple buds 



July 



July 



Sept. 



Sept. 



Nov. 



Nov. 



Nov. 



Nov. 



Nov. 



Nov. 



Nov. 



Dec. 



Dec. 



Dec. 



Dep. 



Dec. 



Dec. 



Jan. 



Jan. 



Feb. 



Aug. 



Nov. 



Nov. 



Dec. 



July 



July 



Nov. 



Jan. 



15,'13 

 16,'13 

 15,'ll 

 27/10 

 1/10 



1/11 



14,'ll 



12,'09 



17/11 



18/11 



18,'ll 



1,'09 



1,'09 



6,'ll 



6,'ll 



14,'09 



18,'09 



8,'13 



13/10 



23/10 



23/10 



26/09 



26/09 



6/09 



15/13 



15/13 



4/11 



18/12 



78.2 

 100.0 

 64.6 

 39.0 

 77.8 

 60.5 

 69.1 

 1.5 

 100.0 

 91.0 

 99.3 

 75.3 

 84.2 

 40.0 

 56.5 

 74.7 

 48.2 

 51.0 

 97.0 

 63.1 

 93.2 

 81.2 

 15.3 

 93.1 

 70.0 

 73.6 

 48.5 

 58.6 



iProcs. Soe. for Hort. Science, 1912, p. 65. (Bibl. No. 69). 



