INSECT PESTS 47 



fibreless appearance, and by their growth in a downward 

 direction. It should be stated that the trench need not 

 be more than two feet or so deep for small trees and 

 three feet for large ones. 



The roots must be cut back before they enter 

 the inferior or perhaps unwholesome subsoil, and 

 the manner in which the cut should be made is of 

 importance. If made in a descending direction, any 

 roots afterwards emitted will almost certainly grow 

 downwards, but, if the cut is made in. a slanting direction 

 upwards, the rootlets that in time make their appear- 

 ance will also grow towards the surface. All roots 

 found to be pushing down towards the subsoil should, 

 after they have been cut as advised, be lifted and placed 

 in a horizontal position. It may not perhaps be neces- 

 sary to have them exactly horizontal, but the idea to 

 be aimed at is to prevent their continuing to descend 

 and to enable them to get nearer the surface, where 

 they will be benefited by the warmth and air. The 

 fact of making the trench all around the tree will 

 to a certain extent be a root pruning in itself, for 

 some of the undesirable roots will most probably 

 have penetrated so far and be cut through by the 

 spade. All roots that are so cut must afterwards be 

 carefully gone over with a sharp knife and the bruised 

 ends again cut, as previously described. Fresh soil 

 placed in the trench to replace that removed, when all 

 the necessary root-pruning is finished, goes far to re- 

 establish the offending roots in their proper positions, 

 for roots will invariably find out new material if it is 

 anywhere within their reach. 



INSECT PESTS 



The apple tree is liable to the attacks of various 

 insect pests, of which the most harmful and generally 



