PRUNING—THE SEASON 453 



tion of fruit buds on the basal and median portions of those shoots. 

 Though such summer pruning may not result in any considerable increase 

 in the total number of fruit buds, it does favor fruit-bud formation 

 in more desirable places and is well worth while. 



Influence on Fruit Color. — In the apple, peach and certain other 

 fruits the development of the red colors in the skin of the fruit depends 

 mainly on sunlight. With those fruits summer pruning naturally 

 influences their coloration, particularly if the pruning consists mainly 

 in thinning out. Vincent*'' reports that summer, as compared with 

 winter, pruning the apple in Idaho resulted in an increase of 33 per cent, 

 of extra fancy apples in Jonathan, 32 per cent in Rome and 5 per cent 

 in Wagener, the grading being mainly on the basis of standard commercial 

 color requirements. The coloring of certain other fruits, as plums and 

 grapes, does not depend on light reaching the fruit itself, though pig- 

 ment formation depends on carbohydrate manufacture in near by 

 leaves. Consequently summer pruning is of less direct aid in the colora- 

 tion of these fruits. Bioletti,^ however, states that judicious summer 

 pruning may occasionally favor the coloring of the fruit in certain grape 

 varieties. Presumably this influence is exercised through the better 

 lighting of the foliage near the fruit clusters. 



Most fruits develop their color late in the growing season or shortly 

 before ripening. Consequently summer pruning to promote a better 

 coloring of the fruit may be done comparatively late. In pruning for 

 this purpose caution should be exercised; too severe or too early summer 

 pruning is likely to result in more or less sunburn of the fruit. 



Summer Pinching. — It is impossible to distinguish clearly between 

 what is termed pinching and what is usually termed topping or heading 

 back. The difference between the operations is siniplj' in the maturity of 

 the tissues at the time the operation is performed and in the relative 

 amount of new growth removed. In some species, as for example the 

 rambles, pinching leads to considerable branching of the pinched shoots; 

 in many others it may be attended by very little branching, one or two of 

 the subterminal buds promptly growing out to replace the leader. Conse- 

 quently its general effect may be concentration or dissipation and dilution, 

 depending on the species and on conditions. Summer pinching has been 

 much used in European fruit growing and in the growing of fruits under 

 glass. In this country it has been used mainly with the brambles and with 

 grapes, though occasionally it is helpful in checking or directing growth 

 in some of the other fruits. 



There seems to be much difference of opinion among growers and 

 investigators as to the wisdom of summer pinching of brambles. Both 

 satisfactory and unsatisfactory results have been reported. Apparently 

 much depends on the time of the operation; furthermore varieties respond 

 quite differently to the same treatment. Macoun^' has reported that at 



