WINTER rXJURY IX RELATION TO SPECIFIC FRUITS 325 



discolored, the youngest or outer layer of wood has been frozen until it is 

 now of a dark-walnut color and the wood is blackened throughout. 

 Many of these trees are of doubtful vitality and will probably succumb. 

 Others have enough vitality to enable them to pull through. Where 

 bark is adhering or only partially separated from the trunk the chances 

 for recovery are good. The tops of such trees are usually found in fair 

 condition, the wood brownish, but the white cambium layer uninjured 

 though lying immediately in contact with brown, dead wood. The 

 twigs, especially the 1-year wood, sometimes have been frozen so badly 

 that they will not be able to push out the leaf buds. In severe cases the 

 leaf buds themselves are killed, but, as a rule, they are still alive. Of 

 course on all such trees the fruit buds are killed. The most injured part 

 is the trunk just above the snow line. ... (3) The third class, which 

 may be described as the moderately frozen trees, in which the wood above 

 the snow line is blackened but the bark not separated from the wood and 

 with the cambium still apparently alive, although water-soaked and 

 injured, frequently has minute brown streaks in the bark immediately 

 in contact with the cambium. Such trees will almost invariably 

 recover. . . . Nearly every tree in the entire Michigan fruit belt 

 was frozen in February, 1899, so that the wood was blackened and dead 

 clear to the bark. A new layer of live white wood formed inward from 

 the white bark, the trees made a fairly good growth, having no fruit crop 

 to carry, and bore the year following a record fruit crop." 



As in the apple, the bark on the trunk near the ground seems to 

 mature late and is particularly liable to injury. After seasons favoring 

 late growth mounding of earth to cover this region somewhat has been 

 found very profitable insurance. In several instances in Ohio in 19G3- 

 1904 a few shovelfuls of earth at the crown made the difference between 

 dead trees and uninjured trees. ^^ 



Chandler^^ records an interesting case of mild injury associated with 

 immaturity. After a very rainy August in 1914 the minimum for 

 the winter, — 9°F., occurred late in December. In the following spring 

 the blossoms of several varieties were at least three weeks late in opening. 

 Examination disclosed injury to the pith of the bud, extending even as far 

 as the pith of the twig. There was very little injiny elsewhere. Usually 

 the flower parts are less resistant than the pith of the bud and of the 

 twig. The temperature evidently was not low enough to kill matured 

 buds but it did damage the immature tissues. The trees in question bore 

 a normal crop that season. Similar cases have been observed at other 

 times. ^* 



Treatment of damaged trees consists of the ordinary prophylactic 

 measures and a moderate pruning. Very heavy heading back, or 

 dehorning, has proved decidedly injurious when the bark or the wood is 

 damaged; a fair amount of pruning is, however, beneficial.*^ This 



