54 maine agricuivturai, experiment station. i912. 



Winter Injury. 



Following the winter of 1910-1911 a considerable amount of 

 winter injury to the trunks of trees was noted in a number of 

 localities in the several orchard divisions. This injury took 

 the form of a severe loosening and splitting of the bark of the 

 trunk; in the less serious cases longitudinal splits occurred, ex- 

 tending through the living tissues to the wood. The bark im- 

 mediately about these splits either stood free from the wood 

 or else was very loosely attached thereto. 



These less severe cases healed to some degree during the past 

 season, to the extent that loosely adhering bark became more 

 firmly attached. In the great majority of cases the injury had 

 been severe enough to cause complete sloughing of the injurel 

 tissues with the advent of warm weather, leaving the wood 

 exposed. 



All gradations of the latter type of damage were found, from 

 cases where a small area the size of a hand had been affected 

 to a few extreme instances where the tree had been practically 

 girdled for several feet from the ground. 



Treatment has been the same as that for removal of a dis- 

 eased area, — namely, cutting away of all dead tissues, disinfect- 

 ing the exposed surfaces and protecting them with a coat of 

 paint. In this way, the greater part of the trees affected will 

 doubtless heal over; those most severely damaged, however, give 

 little hope of recovery. 



The cause of this kind of injury is not known with any cer- 

 tainty, and the question calls for extended study. The com- 

 mon assumption that the growth of the season preceding the 

 winter in which the injury occurred had not sufficiently ripened 

 before the advent of cold weather, does not apply here. The 

 trees incurring the greatest damage made, on the whole, less 

 wood growth than the vast majority that came through the win- 

 ter unharmed. Neither can sunscald be held directly responsi- 

 ble for the trouble, in view of the fact that the injury occurred 

 as frequently upon the northern as upon the southern sides of 

 the trees. 



In the absence of specific experiments bearing on this ques- 

 tion, two factors would seem to have a relation to this type of 

 winter injury. They are insufficient soil drainage and a sudden 



