FOOD FOR PLANTS 139 



(1) a short central limb extending upright from the 

 trunk; (2) a tier of main branches radiating from the 

 point where this central limb joins, or rather, extends 

 out of the trunk; and (3) another tier of main 

 branches, radiating from the upper extremity of the 

 central limb and above the first tier. 



The Modified Leader is a compromise between the 

 Central Leader and Open Center types, combining 

 the good features of the two. It provides for a main 

 central limb up to a certain point, where, by careful 

 pruning over a period of years, it is diverted off to 

 the side somewhat and loses itself into the side 

 branches, thus leaving the top of the tree open for 

 the admission of sunlight. This promises to become 

 the most popular type of pruning. 



Pruning is generally done when the trees are dor- 

 mant, the period from November to April being the 

 usual pruning time. Summer pruning is practiced 

 only under special circumstances. 



Thinning. 



This is an important feature of commercial orchard 

 management. Probably the greatest advantage ob- 

 tained by it is the increase in the size of the remain- 

 ing apples. As a rule the thinning should be done 

 in the South as soon as the May drop is over, and 

 in the North after the June drop. The development 

 of seeds drains the energies of the tree. Hence thin- 

 ning at a later period will not influence the size of the 

 apples as greatly. Great care must be taken in thin- 

 ning, not to injure the fruit spurs. As a general 



