PROTECTION AGAINST FROST 



361 



this stage, the earlier the stage of development the hardier the buds are; and in 

 general, when the fruit is setting the injury is from 5 to 10 per cent, more than 

 when they are in full bloom. 



"Sour cherries are the hardiest, and then follow in order apples, peaches, 

 apricots, and sweet cherries. "2°'* 



Field observations sometimes indicate that open peach blossoms are 

 more resistant than apple blossoms at the same stage. 



At Different Stages of Blossom Development. — Table 66 indicates 

 that the difference in tenderness of blossoms at various stages in their 

 development is well recognized. Table 67, arranged from a similar table 

 by West and Edlefsen, shows experimental data that are, in general, 

 confirmatory. 



It should be remembered that not all the blossoms on a tree are going 

 through the same stage of development at any given time and the amount 

 of damage done by a light to moderate frost will depend to a considerable 

 extent on the number of opened and of unopened buds. This is shown 

 in Table 68. 



Strawberries that are half grown, however, appear able to stand 

 more freezing than the blossoms. 



Coit" reports on this fruit: "Blossoms are injured by temperatures below 

 30° at the ground but young fruit endures temperatures as low as 24° at the 

 ground and 28° in a government shelter without injury and green fruit protected 

 by foliage endures temperatures several degrees below this. Ripening fruit 

 endures less cold, being injured by temperatures below 25° at the ground. A 

 good picking was taken from Excelsior plants Dec. 24, 1903, although the mercury 

 had fallen at the ground to 22 to 26° during 10 nights of the month. Some 



