Callusing and Repairing 



97 



than large ones. The proper practice is, therefore, to prune 



in time, so as to avoid the cutting of large branches. 

 In order to secure a 



satisfactory proportion be- 

 tween the amount of food 



material used in making 



callus, and the supply, it 



is best not to make too 



many large wounds at 



once, and, if possible, no 



wounds larger than four 



to six inches in diame- 

 ter. Three medium-sized 



branches of from three to 



four inches in diameter 



ma}' be safely remo\'ed in 



any one year, even from 



old trees, and the wounds 



will heal in from three 



to six years, while young 



vigorous trees will elaborate enough food material to take 



care of a larger number. 



The wounds on young trees and in the younger portions 



of the trees heal more readily than those on old trees and 



those near the base, removed 

 from the food-elaborating foli- 

 age. In \-ery old trees which 

 are underfed, the callusing pro- 



FiG. 28. — Importel bill hook vu j- 



f liooK. ^ggg ^^^. gQ ^^ ^^.^^^ exceedmg 



slowness or may even be entirely suppressed. \\'ounds on 

 the lower side, shedding water more readily, are less 

 dangerous than those on the upper side of limbs. 



In general, the fewer and the smaller in extent the wounds 



Fig. 27- — An example of proper prun- 

 ing^ but with the wound left undressed. 



