224 



PRUNING 



M 

 " B C 



FIG. 203. Twigs pruned, 



Wounds and their Healing. The 



removal of a branch exposes the stem 

 tissues, and makes an opening where 

 destructive organisms, which may 

 injure or even destroy the plant, can 

 enter. Unless wounds are quickly 

 healed over, the plant will suffer. 



Since tissues that are much spe- 

 cialized, such as wood and corky 

 bark, have lost their ability to grow, 

 the meristematic tissues or cambiums 

 showing the cuts at different dis- must be depended upon to heal the 

 tances from the bud. A, the cut , -r P ,1 ,., f 



is too far from the bud. B, the WOUn(L K the condltlons are favor " 

 cut is so near the bud that the able for growth, the cambiums and 

 bud is probably injured. C, the the cells newly formed from them 

 cut is at the proper distance from develop a mass of tissue known as 

 the bud Why are the cuts made the caRus which sprea ds over the 

 obliquely? , ' ,., 



wound and forms a cap-like covering. 



The development of the callus depends very much upon the 

 nature of the wound and 

 where it is made. The cut 

 should be made with a sharp 

 tool, and so made that the 

 stem will not be split. When 

 a small branch is cut off, the 

 cut should be made just above 

 a bud, as shown in Figure 203, 

 so that the leaves developed 

 from this bud will supply food 

 for the formation of the callus. 

 If the wound is too far above 

 a bud, or if the cut is so close 

 that the bud is destroyed, 

 then there will be a dead 

 stump which will not heal. 

 Side branches should be FIG. 204. An example of bad prim- 

 pruned close to the main ing, showing the dead stubs of branches 

 , T ,, ,, , . which may lead to the destruction of 



branch, so that the cambium the tree ^ Bailey 



of the main branch can heal 



the wound. In Figure 204 is shown an example of improper 



