456 FUNDAMENTALS OF FRUIT PRODUCTION 



newly planted trees the buds within a short distance from the ground 

 often start to grow. Generally the resulting shoots are promptly rubbed 

 off or they are pruned away after they have been allowed to grow a year. 

 In either case the growth of the upper branches is very likely to be checked. 

 If these lower shoots are promptly pinched back so as to leave three or 

 four leaves apiece the upper shoots are not checked in their development, 

 the trunk is shaded and the food materials that their leaves manufacture 

 will be of considerable value in promoting a vigorous growth the following 

 season, after which they can be removed. Similarly in trees that have 

 been growing in the orchard for 1, 2 or 3 years, are formed many shoots 

 that ordinarily are removed at the following dormant-season pruning. 

 Their growth reduces somewhat the development of those desired for the 

 permanent framework. Pinching them back early in the season sup- 

 presses them and the nutrients and moisture are largely diverted into other 

 parts, but at the same time their leaf surface serves to manufacture 

 elaborated foods for the current and the following seasons. 



Summary. — On the whole but little difference is likely to result from 

 pruning at different times during the dormant season, though in certain 

 fruits early pruning is followed by earlier foliation in the spring. This is 

 a factor of commercial importance in grape culture. Very late pruning 

 generally leads to more bleeding than earlier pruning. Bleeding from 

 pruning wounds seldom harms the plant. 



Summer pruning may have a dwarfing or an invigorating influence 

 (as compared with a corresponding winter pruning), depending on its 

 severity, kind, the stage of development of the plant and on environ- 

 mental conditions — particularly nutrient supply, soil moisture and light. 

 A light summer thinning encourages fruit-spur formation through favor- 

 ing the development of larger and stronger lateral buds from which spurs 

 are formed. The same practice promotes fruit-bud formation also if the 

 work is done early enough in the season. Heading back tends to stimu- 

 late purely vegetative growth. Judicious summer pruning is more or 

 less a conservation measure. This applies particularly to the removal 

 of watersprouts and other superfluous growth. In very strong vigorously 

 growing trees 2 to 5 years old early summer pruning results in encouraging 

 a late secondary growth and this may be a means of hastening the general 

 development of the tree if there is a long growing season and other condi- 

 tions are favorable. A light summer pruning may aid materially the 

 coloration of fruit in certain species. 



Summer pinching in general encourages the development of sec- 

 ondary shoots. This is often desirable in the culture of the bramble 

 fruits. Pinching may be used also to subordinate individual shoots and, 

 in the spur-bearing species, it may result in their developing into spurs. 

 This practice is of doubtful utility, however, in the culture of standard 

 trees. 



