422 



FUNDAMENTALS OF FRUIT PRODUCTION 



On the other hand heading back has a more stimulating influence and 

 the pruned shoots tend to give rise to as much (often more) new shoot 

 growth as would have arisen from the unpruned tree. This is well 

 illustrated by Figs. 50 and 51 which show the response of two trees of 

 Grimes to the same amount of pruning, the tree on the left having been 

 headed back and that on the right having been thinned out. 



Table 11. — Influence of Heading Back and Thinning Out on Shoot and 

 Spur Formation in Young Apple Trees 



{After Gardner^'') 



o a 



« M 6 



e-^2 





Grimes 

 Grimes 

 Grimes 

 Grimes 

 Gano . . 

 Gano . . 

 Gano. . 

 Gano. . 

 Rome. 

 Rome. 

 Rome. 

 Rome. 

 Esopus 

 Esopus 



26-50 

 2&-50 

 51-75 

 51-75 

 26-50 

 26-50 

 51-75 

 51-75 

 26-50 

 26-50 

 51-75 

 51-75 

 46-76 

 4fr-76 



697 

 731 



450 

 462 

 560 

 562 

 507 

 508 

 1007 

 682 

 444 

 461 



Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 

 Thinning 

 Heading 



4123 

 5703 

 2308 

 3328 

 4577 

 6293 

 5072 

 5846 

 3352 

 3915 

 4785 

 4474 

 2122 

 4031 



360 



322 



130 



101 



158 



158 



110 



111 



43 



25 



54 



25 



180 



144 



Influence on General Shape and Habit. — Incident to quite different 

 effects of heading and of thinning upon the amount of new shoot growth 

 and the number of new spurs are the influences of these practices on gen- 

 eral shape and growth habit. Thinning out places no check on the 

 natural tendency to grow principally from the terminal and subterminal 

 buds. Consequently plants pruned exclusively in this way grow tall 

 and wide spreading and they gradually develop a more open, "rangy" 

 habit than they would otherwise. This may be advantageous or dis- 

 advantageous to the grower, depending on a number of conditions. On 

 the other hand constant heading checks this tendency to extend out and 

 up and results in a plant compact in habit and often very dense in growth. 

 The average well kept hedge furnishes an extreme example of the direc- 

 tion in which all heading tends. Indeed much of the usual pruning of 

 the bramble fruits, which consists largely in heading back both leaders 

 and laterals and the pruning that frequently is afforded other deciduous 

 fruits — especially when they are young — results in a type of growth and 



