258 DISEASES OF TROPICAL PLANTS CH . 



disease spores during the long time of exposure necessary 

 before healing over has been completely accomplished. 



For treatment of such large wounds many substances 

 have been recommended, but in general an ordinary stiff 

 white lead paint will suffice. Too much oil in the paint 

 should be avoided as the free oil will often seriously injure 

 the cambium layer of the wound and prevent healing. 



If a paint is too thin it may be thickened by the 

 addition of ochre. 



Coal tar may be used, and the ordinary grafting 



FIG. 84. Tree showing proper method of removing a branch. 

 (Photo by J. J. Taubenhaus.) 



waxes are sometimes used, but they usually peel off 

 after the the first season. 



If a wound is rough, carefully pare it off smooth, 

 especially the edges. Very large wounds can often be 

 protected by tacking a piece of tin, that has been cut 

 to fit, over the wound. Such a piece of metal should 

 be a little smaller than the surface of the wound, thus 

 allowing a layer of new wood to form over its edges. 



When large decayed spots are formed in either 

 trunks or limbs of trees they can often be successfully 

 filled with concrete. In concreting a cavity great care 

 must be used to clean out all decayed and decaying 

 wood before putting in the filling. 



