270 The Commercial Apple Industry 



leader is maintained for one or more years, at which time 

 it is removed in order to open up the center of the tree. 



Small side shoots and fruit-spurs developing in the 

 middle of the tree during this time should be left. Such 

 wood is productive of early fruit. Furthermore, an abund- 

 ance of foliage and small twigs are necessary to protect the 

 main limbs from the sun and also to aid growth. There 

 must be plenty of foliage and twig growth if young trees 

 are to produce wood. 



VEGETATIVE, TRANSITORY AND FRUITAGE STAGES 



A tree may be said to pass through three distinct periods : 

 (1) formative period, (2) transition period, and (3) fruit- 

 ing period. The treatment, both in regard to pruning and 

 soil management, changes materially with each of these 

 periods. It is during the formative period that the tree 

 devotes its energies to the formation of wood growth. The 

 proper selection, distribution and training of scaffold 

 branches during this time determines the ability of the 

 tree to bear and carry heavy loads of fruit in later years. 

 The length of the formative period is usually from four to 

 six years, depending on the region and treatment provided. 



Transition period. 



Although less distinct, this period is critical. Between 

 the fifth and eighth year the tree is undergoing a change 

 from vegetative to heavy fruit production. The exact age 

 will vary with the region, variety and treatment. Some 

 varieties may not pass through this period until they 

 become ten or twelve years old. Other varieties and par- 

 ticularly when grown under irrigation begin to bear heav- 

 ily at six and seven years. 



