﻿ON FROST INJURIES TO SYCAMORE BUDS. 



BY HERMANN VON SCHRENK. 



The native forest trees of the temperate zone rarely show 

 evidences of injuries due to frost. The reason for this is 

 probably to be found in the fact that most buds start to de- 

 velop at a period when severe frosts are no longer liable to 

 occur. Frost injuries, such as are commonly found, usually 

 occur in cultivated trees, particularly the fruit trees. Now 

 and then, however, cold weather and heavy frosts occur 

 during the late spring, and at such periods injuries are liable 

 to be found in even the native trees. The extent to which 

 native forest trees are subject to frost injury during the spring 

 of the year is but little known at the present time. The spring 

 of this year was characterized by extraordinarily cold weather 

 and by heavy frosts, particularly during April and May. 

 These frosts came at a time when buds on most trees had 

 ah-eady begun to open, and in many instances trees had al- 

 ready formed leaves one to two inches in diameter. As is 

 usual in such cases, fruit trees suffered very severely. The 

 blossoms on apple and peach trees were almost universally 

 killed throughout Missouri and northward, and in many lo- 

 calities in the Eastern States. 



By the middle of May, most forest trees, especially maples, 

 sycamores, elms, poplars, etc., had developed leaves of con- 

 siderable size. After the last considerable frost, notes were 

 made in the vicinity of St. Louis and in New Jersey concern- 

 ing the extent to which the various species of trees had been 

 influenced by the frost. With the exception of the sycamore, 

 most trees showed but slight injury. Some of the youngest 

 leaves were killed at the edges, but hardly any of them were 

 killed outright. The young leaves of the sycamore, on the 

 other hand, were very universally killed entirely. A few 

 days after the frost, the edges of these leaves turned reddish 

 and ultimately brown, and some weeks after, the leaves were 

 thoroughly dry and papery. Many of the buds which were 



6 (81) 



