PRUNING PRINCIPLES 



111 



The effects of stripping were offset by those of spring pruning. 

 Stripping at the three seasons already mentioned, in the absence of 

 spring pruning, stimulated fruit bud formation uniformly. 



Not enough is yet known about the operations of root pruning, 

 ringing and stripping for the formulation of rules by which prac- 

 tical fruit growers may utilize these operations advantageously in 

 their orchards to increase the fruitfulness of their trees. 



103. 14. A constriction or a girdle on a twig or a stem 

 lends to increase and elongate growth from the buds nearest 

 below and to thicken the 

 twig immediately above 

 (Fig. 96). The bud 

 nearest above a constric- 

 tion or a girdle usually 

 becomes more or less 

 quiescent and often 

 fruitful (Fig. 95). 



This principle is based 

 upon the upward move- 

 ment of crude sap and 

 of elaborated plant food 

 (20). The influence 

 which a constriction ex- 

 erts is largely propor- 

 tional to the degree of 

 the constriction. When 

 only the tissues outside 

 the cambium are 

 affected, the buds and 

 other parts above the 

 constriction become 

 filled with elaborated 

 plant food because this 

 material cannot go low- 

 er down the stem ; when 

 the alburnum or sap- 

 wood is affected the up- 

 ward flow may be 

 checked completely, in which case the parts above will die 



FIG. 75 SHOOT GROWTH FROM STUBS 



LEFT IN MAY 



Almost as bad as winter pruning in the pro- 

 duction of increased quantities of wood. 



