22 



BULLETIN 205. 



grows erect and injures the symmetry of the tree. Branches to be 

 removed should be cut off even with the trunk. This rule should 

 be invariably followed with all trees, the conifers not excepted, 

 even though the labor be increased five-fold. When large 



branches are shortened or re- 

 moved, splitting and tearing 

 may be prevented by making 

 two cuts, the one beneath the 

 branch being made first and 

 followed by another above and 

 about a foot farther from the 

 trunk. A dead limb should 

 be cut back even with the 

 shoulder at its base. 



The work of pruning is by 

 no means complete until the 

 wounds are carefully smoothed 

 down and properly dressed. 

 This treatment enables the 

 healing tissue to cover the 

 wounds in the shortest possi- 

 ble time and prevents the 

 decay of the wood while heal- 

 ing is taking place. Exposed 

 wood gradually loses water 



and cracks are produced in which dust and moisture col- 

 lect and form a substratum for the growth of bacteria and 

 moulds. Later the spores of larger fungi enter and by develop- 

 ing in this mass of decayed wood become sufficiently vigorous to 

 attack the heart-wood and thus pass into the trunk of the tree. 

 If some substance is applied to the wound which will prevent 

 the evaporation of water and the consequent checking, decay may 

 be avoided. Various mixtures have been used for this purpose, 

 of which lead paint and coal, tar are probably the best. Both 

 are antiseptic as well as protective, if applied in thick layers. 

 In the case of large wounds, which require several years to heal, 

 it is well to put on a second coat after two or three years. Thin 

 coal tar is not suitable for this purpose as it does not prevent 



FIG. 24. Pruning properly done, 

 but wound not dressed. 



