CHAPTEE V. 



OTHER FACTORS IN FRUIT PRODUCTION. 



The fruiting of a pear tree is controlled by a number of different influ- 

 ences. The question of the fruitfulness or unfruitfuluess of a given tree 

 or orchard is a complicated problem and should not be looked upon 

 from a single point of view. While the principle of cross-pollination 

 is important, it is only one of a number of factors which determine the 

 fruitfulness of a tree. Before drawing any general conclusions in 

 regard to the pollination of the blossoms it will be desirable to discuss 

 some of the other factors. 



THE EFFECT OF VEGETATIVE VIGOR. 



By vegetative vigor is meant the vigor of the tree in relation to 

 growth. A tree with large dark -green leaves and strong thrifty an- 

 nual growth has this quality well developed. It is a common experi- 

 ence among fruit growers that a tree must be in good vegetative con- 

 dition to bear a full crop of fine fruit. The vegetative vigor affects not 

 only the size of the fruit, but the per cent of fruit which sets. It is 

 true that an excess of vegetative vigor x)rev-ents the tree from forming 

 fruit spurs and fruit buds, and in case of a very young tree seems to 

 prevent the fruit from setting on the blossoms which are formed. A 

 young tree, or an old tree severely pruned back, must get over its 

 period of exuberant growth before it is in condition to bear. Some- 

 times, with certain varieties, in an orchard of bearing age the trees 

 will "go all to wood" and not bear. This is much less liable to occur 

 with dwarfs than with standards, unless the dwarfs get rooted above 

 the quince stocks. 



With the exceptions above noted, the general statement may be made 

 that with trees of bearing age the more vigorous the tree the more fruit 

 it will yield. Lack of vigor of growth is much more apt to be the fault, 

 in case of trees which do not bear well, than an excess of it. After 

 trees come into full bearing, the usual tendency is to cover them- 

 selves with fruit spurs, bloom, and bear very heavily for a year or two, 

 and then become so checked in growth as not to do well afterwards 

 mless attended to. Such trees often bloom heavily and yet set a very 

 jjmall per cent of fruit because the blossoms are not well nourished. A 

 tree in good condition should have a reasonable number of vegetative 

 shoots and fruit spurs and a pro]3er x^roportion of the latter. 



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