74 JOURNAL OF AGRICULTUEE OF P. R. 



stated, this consists of preventing wonnds in so far as possible, and 

 of the proper treatment of those that do occur, in order to prevent 

 infection by wood-destroying fungi. 



Mechanical wounds due to cultivation instruments, animals, or 

 other agencies should be prepared for treatment by having all pro- 

 jecting stubs, loose bark and ragged edges of bark and wood cut off 

 or smoothed down so that healing over by growth of new bark tis- 

 sues can proceed as easily and as rapidly as possible. The wound 

 itself may be treated according to recommendations given in latter 

 paragraphs. 



In those cases where foot-rot, pink disease, psorosis, or other 

 primary diseases are the causal agents more care is necessary. Dis- 

 eased branches should be removed by cutting well back to a healthy 

 limb, or to the Trunk itself. Cankers on branches and trunk due to 

 specific diseases must be carefully worked over to remove every 

 trace of diseased tissue. This involves removing not only the dis- 

 colored bark, but the diseased wood beneath as well. As a precau- 

 tionary measure cutting out should extend well into healthy bark 

 and wood, a half inch at least. All diseased material removed should 

 be buried deeply or preferably burned. A piece of sacking laid 

 around the tree will serve to catch small fragments as they are cut 

 away from the tree. 



In ordinary pruning operations for the removal of dead wood 

 and the shaping of the tree, certain precautions should be observed. 

 In so far as possible branches which threaten at some time to inter- 

 fere with others or to spoil the symmetry of the tree should be 

 removed. Superfluous limbs should be removed at as early a stage 

 as possible to avoid large w^ounds, and other difficulties attendant 

 upon their removal. Most important of all is the necessity of close, 

 clean cuts. The careless habit of leaving stubs of various lengths, 

 even if only an inch or le^s in length, is responsible for a large per- 

 centage of wood rot. To avoid splitting, the precaution should be 

 talven of removing large branches in two pieces, the first cut made 

 a foot or so above the base of the branch to be removed, and then 

 the second, final, careful cut, at tlie point of union with limb or 

 trunk. 



Where there is any tendency to bleed, further treatment of wounds 

 should be postponed until the surface is dry. Witli citrus, however, 

 this is rarely necessary. In the case of wounds resulting from foot- 

 rot, Diplodia canker or other diseases, the next step after cleaning 

 out all diseased tissues and making the edges smooth to permit of 



