424 



FUNDAMENTALS OF FRUIT PRODUCTION 



Table 12. — Influence of Thinning Out and Heading Back Shoots on Fruit- 

 bud Formation in the Apple 

 (After Gardner'^-) 





•SS2 



i ^ 





Grimes 

 Grimes 

 Grimes 

 Grimes 

 Grimes 

 Grimes 

 Gano. . 

 Gano . . 

 Gano . . 

 Gano . . 

 Rome. , 

 Rome. , 

 Rome . , 

 Rome . . 

 Rome. . 

 Esopus 

 Esopus 

 Esopus 



No pruning 

 Thinning 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 No pruning 

 Thinning 

 Heading 

 Thinning 

 Heading 

 No pruning 

 •Thinning 

 Heading 



1-25 

 26-50 

 26-50 

 51-75 

 51-75 

 26-50 

 26-50 

 51-75 

 51-75 



26-50 

 26-50 

 51-75 

 51-76 



41-76 

 41-76 



402 



457 



360 



322 



130 



101 



158 



158 



110 



111 



142 



43 



25 



54 



25 



635 



180 



144 



37.2 

 33.3 

 44.3 

 18.5 

 25.1 

 2.4 



103.8 

 96. 

 67. 

 81, 



107. 

 54. 

 32. 

 59. 



12,7 

 52.6 

 24.5 

 31.1 



detailed study of the table brings out a number of additional points. In the 

 first place, it is noted that thinning, as compared with an equally severe heading, 

 almost invariably led to an increased production of fruit buds upon fruit spurs. 

 The one exception to this statement is furnished by the heavily headed Gano 

 tree, a variety in which severe heading of short shoots in the interior seems often 

 to have the effect of forcing the development of strong fruit spurs from the remain- 

 ing lateral buds. The short interior shoots of other varieties do not show such a 

 tendency to respond to severe heading in this way. Heading-back was invariably 

 accompanied by a greater development of terminal fruit buds on shoots than 

 thinning out. In the case of a variety like Gano, that when young bears a 

 large percentage of its fruit buds in this way, this effect may be sufficient to give 

 the tree a larger total number of fruit buds than correspondingly thinned trees. 

 Attention is called, however, to the fact that a continuation of the winter heading 

 year after year would remove the fruit buds on all the shoots headed and thus 

 actually result in decreased flower and fruit production as compared with thinning. 



"Another point worth noting, but not brought out in the table is the fact 

 that the shoots bearing terminally average much shorter in the thinned than in 

 the headed trees. They are generally so placed, moreover, that in the thinning 

 of shoots they can be left to advantage while sterile ones are taken out. 



"Except for Esopus, winter thinning of shoots, as compared with heading, 

 led to greatly increased production of lateral fruit buds on shoots. In the case 



