284 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 



Some trees were found which clearly showed that such an occur- 

 rence actually took place. The bark on the north side of a three- 

 year-old lemon tree had been longitudinally split and had separated 

 from the wood for an inch and a half or so on each side of the split. 

 At one place it had been tied down to the tree again by a piece of 

 twine, which brought the wood and bark together at this place only. 

 Both above and below the twine the bark had remained separated from 

 the tree. The bark was not killed, and where it had been tied it had 

 reunited firmly with the tree. 



Fig. 11. Cross section of young lemon trunks on which bark was split 

 by freezing, showing the injury to the wood which is dead back to the inked 

 lines. New wood can be seen forming on the loose ends of the bark which 

 was not killed. 



In many cases where split trees were wrapped the process was so 

 thoroughly done that the moisture was held in and molding favored. 

 The best instances of recovery from wrapping were those where cord, 

 like binding twine, or narrow strips of cloth were wrapped around 

 the tree spirally, leaving the greater portion of the bark uncovered 

 and allowing the free access of the air, but holding the loose bark 

 firmly against the wood. Such wrapping to have any effect must 

 be done promptly after a freeze, while the injured surfaces of bark 

 and wood are fresh, otherwise the wrapping naturally could have no 

 beneficial effect. Where bark is split and loosened it is likely to bend' 

 outward a.3 it dries and exert a force that will have a tendency to 

 extend the injured area. Binding with cord as indicated will prevent 

 such extension of the injury and favor the bark healing on, while 



