370 SEEDING AND PLANTING 



Since every cut produces a wound through which the spores 

 of fungi may gain access to the living tissues of the tree, as little 

 pruning should be done as is necessary to maintain a proper 

 balance between root and shoot. In many cases the diseased 

 condition of young stands of timber can be directly traced to 

 injurious fungi gaining access to the trees at the time of planting. 

 Plants should be lifted with the least possible injury to the root 

 system, particularly to the fine rootlets which constitute the 

 chief absorbing surface, as this precaution will usually make the 

 pruning of the top unnecessary. In cases where the trees are 

 lifted with balls of earth about the roots, there is the least dis- 

 turbance in the natural balance between root and shoot and 

 there is the least necessity for pruning the top. 



The chief advantage of nursery-grown stock over wild stock 

 lies in the fact that the former has a better root system and the 

 plants are lifted with much less damage. The pruning of small 

 nursery-grown trees can usually be avoided because with suitable 

 care they can be grown with a compact root system which can be 

 lifted with little injury. 



12. CONDITIONS UNDER WHICH PRUNING is DESIRABLE 



Under the following conditions root or shoot pruning is desirable 

 prior to planting: 



a. When for one reason or another there is not a proper pro- 

 portion between root and shoot. 



b. When certain roots have been severely injured. 



c. When the tap root is unusually long, making planting ex- 

 pensive and inconvenient. 



d. When there is more than one leader. 



e. When there are abnormally developed side roots or side 

 branches, or the trees are otherwise ill-shaped. 



It is safer to throw away ill-shaped trees and those with a 

 defective root system than it is to plant them after the necessary 

 pruning and invite the introduction of disease. 



13. INJURIES FROM PRUNING 



The injury from pruning depends chiefly upon the species and 

 the locality. On the whole, broadleaved species withstand pruning 

 better than conifers. The amount of injury is chiefly dependent 

 upon the degree of exposure to fungous diseases and the rapidity 



