SECTION IV 

 PRUNING 



Fruit production by the trees, shrubs and vines that yield edible 

 fruits is dependent on (1) the possession of the mechanism or machinery 

 for fruit production that is characteristic of the species or variety in 

 question and (2) its proper and more or less efficient functioning. Thus 

 it is characteristic of most varieties of the brambles to bear fruit clusters 

 terminally on short shoots developing from lateral buds on year-old 

 canes. If the plant is so handled as to prevent or reduce the formation 

 of lateral shoots of this type, fruiting is correspondingly limited. It is 

 characteristic of certain varieties of the walnut to bear terminally only 

 on short shoots developing from terminal buds on the growth of the previ- 

 ous season. Obviously then the production and preservation of terminal 

 buds is a prerequisite to fruit production in those varieties. The peach 

 bears fruit on shoots of the past season but only at nodes from which no 

 lateral branches arise. 



However, some of the lateral buds on last year's raspberry and black- 

 berry canes do not produce fruiting shoots; some of the shoots from ter- 

 minal buds of the walnut are barren and many nodes on the unbranched 

 primary peach shoot do not have fruit buds. The framework, the 

 machinery, for fruit bud formation is apparently there, but no fruit buds 

 are formed. The mechanism does not function in the way it is desired. 

 This functioning or non-functioning of the fruiting machinery is to be 

 regarded as a definite response to varying conditions within the tree — 

 primarily conditions of nutrition, which in turn may be influenced by 

 age, vigor, food supply, temperature, humidity and many other factors. 



In some cases production is limited by the amount of fruiting machin- 

 ery, or, as the grower would say, the amount of bearing surface. In 

 others the limiting factor to production is the irregular, imperfect or 

 inefficient functioning of the fruiting mechanism. For the grower the 

 ideal condition is to have the plant well equipped with fruit producing 

 machinery and to have that machinery working efficiently. One or two 

 further parallels may be drawn at this point between the living plant and 

 the hypothetical manufacturing establishment with which it has been 

 compared. Good equipment with fruit producing machinery does not 

 mean the maximum amount that can be crowded into the available room 

 any more than an amount plainly inadequate for the establishment. Too 

 much fruiting wood unduly taxes the tree for its maintenance. On the 



388 



