21 



As infection occurs through the entrance of the spores into exposed 

 places in the heartwood of a tree, where thej' germinate and bring 

 about the changes described, the treatment should be preventive, 

 not curative. All sporophores which form on the trees should be 

 destroyed and diseased trees should be removed, as they may give 

 rise to sporophores which may escape notice. The retention of such 

 diseased trees as seed bearers does not seem desirable in the case of 

 the red cedar, as there are so many healthy trees which could serve 

 the same purpose. It is also advisable to cut trees after thev have 

 reached a certain age, as old trees are more liable to attack than 

 younger ones, the liability increasing Avith age. The best age for 

 cutting varies with localit3\ In very favorable situations, where the 

 trees grow very rapidly, theV may be cut with profit when but half 

 the age at which it would be best to cut trees growing on mountains 

 or in exposed situations, where growth is ver}' slow. A good age at 

 which to cut the trees in Tennessee is from 65 to 70 3'ears — in other 

 words, when the trunk is about 1 foot in diameter. 



