406 FUNDAMENTALS OF FRUIT PRODUCTION 



flowering shoots or spurs. Fruit bud differentiation depends on 

 nutritive conditions in and about the terminal bud at such time or times 

 when differentiation can take place. Terminal bearing involves a definite 

 limitation to shoot or spur extension in a straight line. New vegetative 

 extension must be from lateral buds if all terminals form fruit buds in 

 one season, but this seldom occurs and those buds that do not become 

 fruit buds one year may therefore become differentiated into fruit buds 

 the next season. In this way regular annual bearing is possible if nutri- 

 tive conditions within the plant remain such that fruit bud differentia- 

 tion can occur each year. Even if all terminals were to differentiate 

 fruit buds one season and to flower and fruit the next, there would still 

 be opportunity for the formation of another set of fruit buds terminally 

 on the new shoots or new spurs. Therefore regular annual bearing would 

 still be possible provided nutritive conditions were favorable. The 

 terminal fruiting habit does not in itself lead to alternate bearing except 

 in the event that practically every terminal forms a fruit bud one season 

 and sets fruit the next while at the same time growing conditions this 

 second season prevent fruit bud differentiation on the new shoots or 

 spurs developed from lateral buds. When this extreme is encountered 

 it should be handled as a problem in nutritive conditions to be corrected 

 by the control of environmental factors. In other words, though many 

 varieties of plants which bear fruit buds terminally are much inclined 

 to alternate bearing, that tendency is not a necessary product or accom- 

 paniment of terminal fruit bud formation. 



Obviously the production of fruit buds laterally on either spurs or 

 shoots makes every provision for regular annual bearing, not only of 

 the plant as a whole, but of the individual part, if conditions within the 

 plant are favorable for fruit bud differentiation. 



Regularity of bearing, therefore, is a cultural problem, to be dealt 

 with by influencing nutritive conditions. Attention is given to this 

 phase of the question in the section on Nutrition. 



Possible Causes of Different Bearing Habits. — Knowledge of bearing 

 habits is decidedly fragmentary and little is known concerning the factors 

 which may control it or influence it in any way. However, it is known 

 that the apple with its characteristic terminal fruit bearing habit stores 

 the bulk of its starch in the pith while the peach with its characteristic 

 lateral fruit bearing habit stores the bulk of its starch in the leaf gaps. 

 Since carbohydrate, and particularly starch, accumulation is so closely 

 associated with fruit bud differentiation, at least in the apple, it is 

 possible that anatomical structure may have much to do with the region 

 of starch storage and that this in its turn may be an important factor 

 determining the bearing habit. 



Summary. — The general purpose of all pruning is to increase yields, 

 improve grades and reduce production costs. These objects may be 



