168 The Farm Woodlot 



SUNSCALD 



Sunscald is more likely to occur in the case of lawn or 

 park trees than in the woodlot. It is caused by the direct 

 rays of the sun scorching the bark and cambium layer of 

 the trunk. Only the smooth, thin-barked trees are ex- 

 posed to this danger. Maples and basswoods are particu- 

 larly susceptible. It almost invariably occurs on the 

 southwest side where the sun strikes hottest. The burn- 

 ing kills the growing tissue just under the bark and causes 

 the bark to peel off in patches. The result is an ugly 

 wound, an easy mark for fungi, that weakens the trees and 

 sometimes causes their death. If left exposed, such a 

 wound can never heal over. In the lawn or park, the 

 trunks of these thin-barked trees should be wrapped with 

 burlap or straw until the crowns have grown sufficiently 

 to shade them. In the woodlot they can be shaded by 

 other trees or underbrush. Sprouts from the roots, that 

 do not look well on ornamental trees, can here be allowed 

 to grow to protect the trunk. Care should be taken not 

 to leave such trees exposed on the south or west side of 

 the tract. When the scalding has taken place, the in- 

 jured tree should be cut out before it becomes a breeding 

 place for insects and fungi. The lawn tree, if wrapped 

 before the scalding has spread too far, will heal the wound 

 in time, but such a healed-over wound is especially sus- 

 ceptible and should never be exposed again. 



INSECTS 



When the supply of timber in the United States seemed 

 unlimited, the comparatively insignificant ravages of the 



