162 PRINCIPLES AND PKACTICK OF PRUNING 



heartwood-destroying fungi, start in the center or pith and seldom 

 if ever affect the true sap wood, always paint from the center of 

 the wound outward. Instead of painting across the sap wood clear 

 to the bark, the ordinary way, leave a circle absolutely bare around 

 the outside from fy& of an inch to an inch in width. Remember 

 that these oils will penetrate a little farther than you paint, es- 

 pecially at the base. So you must have a care about using a too 

 heavilv charged brush. It is good practice to have a rag handy to 

 swab away any surplus. 



In using these oils, the addition of just enough coal tar to give 

 them a dull black color after drying will overcome any tendency 

 they may have to drying in or out, so that they at least appear to 

 have partly faded away. The main reason for this appearance is 

 that the oils have sunk deeply into soft, decaying spots, the result of 

 the decay traveling from some hole through the pith of the 

 parent limb to the wound affected. For best results in preserving 

 wood, two coats are usually recommended. The second may be 

 applied at any time a month after the first, but ordinarily some time 

 after next year's pruning will be most feasible. 



It is sometimes desired to stimulate quick healing. While the 

 cut or a barked place anywhere is fresh, paint the edge of the bark 

 and the sap wood only with liquid wax. This is made as follows : 

 Best white yellow will do resin, one pound ; beef tallow, one 

 ounce. Melt together, remove from the fire and stir in eight ounces 

 of alcohol. Keep and use from a wide-mouthed bottle tightly corked. 

 Through a hole in the stopper, thrust a small brush for applying the 

 solution. Perfect results have been secured by the use of this 

 material. 



135. Available antiseptic materials.* According to A. D. Selby 

 two steps in wound treatment may be found necessary in mam- 

 cases, although in the average case of pruning to remove a branch 

 with a healthy base only one may be essential. These steps are : 

 (1) Sterilization of the wound surface per se. (2) The application 

 of a dressing to protect from infection through the entrance of 

 spores or bacteria. 



(1). The sterilization consists in killing any possible spores or 

 bacteria, etc., that may be upon the surface, by the use of a torch to 

 cauterize the surface, or more easily by the application of an anti- 

 septic or spore-destroying substance. Among these germicides are 

 corrosive sublimate, gasoline, kerosene, carbolic acid, petroleum, 

 copper sulphate solution, carbolineum, formaldehyde, etc. The 

 availability of any of these processes will depend especially upon the 

 effect on the living layer of the wounded surface. If the cambium 

 is killed appreciably it will raise the question of possible injury. 



Because of such possible injury only corrosive sublimate, copper 

 sulphate and formaldehyde are apparently safe. Petroleum com- 



* Paragraphs 135 to 142 have been excerpted and condensed from Circular 12t> 

 of the Ohio Agricultural Experiment Station. 



