276 



PRINCIPLES AND PRACTICE OF PRTXIXG 



work is done in large stubs, which tend to produce far 

 longer and usually weaker growths. Apple and pear trees 

 under five years may be changed to the new variety in 

 perhaps two years, half the top each year; but mature 

 trees should not be worked over so fast not faster than 

 . , four to six years, de- 

 pending on size, age 

 and character of 

 growth. Mature stone 

 fruit trees may be top- 

 worked, but though 

 young trees may de- 

 velop good tops, little 

 if any time is gained 

 because nursery trees 

 of these specie*; come so 

 quickly into bearing. 



While proper setting 

 of the cions is impor- 

 tant, the after care of 

 the trees is at least as 

 necessary. Unless this 

 care is given even the 

 best "take" of cions 

 may prove a more or 

 less dismal failure in 

 developing a new top. 

 Usually the c\ou^ 

 which "take" develop 

 rather rank shoots 

 which, while looking 

 strong, yet if left to 

 themselves may be top- 

 heavy and therefore weak and easily blown out by wind 

 or knocked out by snow, ice, birds or accidents. They 

 should be headed in when, say, 18 inches long, so as to 

 make them branch rather low down. Sometimes the 



FIG. 236 ONE SEASON'S GROWTH ON 



TOP-WORKED APPLE 



New growth headed back after second season. 

 Compare Fig. 235. 



