129 



The frequency with which winter or sjDring injury is definitely 

 known to occur gives color to a rising theory that freezing temper- 

 atures may jalay a vastly greater part in the development of the nut 

 industry over the entire country than is commonly supposed. Much of 

 the evidence of damage from this cause is of such nature as to be easily 

 over-looked or attributed to other causes. Trees and plants of many 

 kinds hive become so accustomed to injury by freezing that they are 

 able to recover without the injury always being apparent. A few illus- 

 trations of this which have come to the writer's attention might be 

 cited. 



In December 1919. a sudden drop in temperature of from 32°F to 

 24 °F occurred at McMinnville, Oregon, with fatal result to cultivated 

 trees and shrubs of many kinds. The damage was greatest in flat bot- 

 toms, especially those where neither land nor air drainage was good. 

 Under such conditions, numerous apple orchards were killed outright. 

 Prunes and Persian walnuts were so badly injured to the snow-line that 

 subsequently great numbers of trees were cut down. Both staminate 

 and pistillate buds of filberts above the snow were practically all de- 

 stroyed. Later on. the entire tops of many of the older-bearing fil- 

 bert trees succumbed. An instance of particular interest, in so far as 

 'this discussion is concerned, was afforded by the beliavior of a shag- 

 bark hickory tree in IMcMinnville, some "iO or 30 years old, which had 

 been grown from a Missouri seed. In P'ebruary, when examination 

 was made of the condition of this tree, it was found that all visable 

 buds had been killed, yet the bark on the branches l)etween the buds 

 was in apparently perfect condition. The question as to what the tree 

 would do. therefore, became one of great interest. The following 

 September, when revisited, this tree was found to have such a wealth 

 of luxuriant foliage thU the observer felt that the accuracy of his 

 February re^'ords was challenged. However, closer inspection showed 

 that growth had entirely taken place from adventitious buds, and that 

 the dead buds and spurs were still in evidence. There were no nuts 

 on the tree but otherwise the casual observer would not have suspected 

 that the tree had been affected in any way. In all likelihood, the owner 

 of the tree would deny that it had been injured. 



Another case of somewhat similar kind occurred early during the 

 present year in a pecan orchard in South Georgia. The trees had 

 been set in 1917, and in 1919, a portion selected by the Bureau of Plant 

 Industry for conducting a series of fertilizer and cover-crop experi- 



