PREVENTION AND REPAIR OF MECHANICAL INJURIES 141 



crotches may be treated in three ways to prevent split- 

 ting, (a) One of the branches may be completely cut 

 off at planting time or while still small. Doubtless this 

 is generally the safest and most satisfactory method 

 because it disposes at 

 once of all possibility 

 of breakage, (b) One 

 of the branches, the 

 smaller usually pre- 

 ferred, may be cut back 

 severely so as to make 

 it develop into a side 

 branch rather than in- 

 to a leader. Often 

 this is an effective plan, 

 especially if the prun- 

 ing be such as to spread 

 the tree and make the 

 side branch less erect 

 than it would be as a 

 leader, (c) The third 

 method applies or 

 should apply only when 

 the Y-crotch has not 

 been treated as above 

 suggested, but has been 

 allowed to grow for a 

 year to, say, perhaps, 

 ten years. A brace of 

 living wood may be de- 

 veloped between the two 

 arms of the Y so as to 

 form, when finished, an 

 inverted capital letter A. 



Usually the best way to secure such a brace is by 

 twining together two living branches produced by op- 

 posite arms of the Y. Preferably each branch should be 



FIG. 99 HISTORY OF A CROTCH SPLIT 

 These sections of a black cherry limb show 

 the progress of decay downward between the 

 branch and the main trunk. In the top sec- 

 tion the decay has progressed to the extent 

 of separating the two parts not so much as 

 shown, but with a distinct cleavage. The 

 middle and lower sections show the decay 

 working downward at the discolored spot on 

 each. 



