256 



PRINCIPLES OF PLANT CULTURE 



of a small branch, should it occur, is less serious than that 

 of a large one. In forming the head of fruit trees three 

 or four foundation branches may be used, but these 

 should by proper pruning be made to develop other smaller 

 ones relatively close to the main trunk. Forks in the 

 trunk of fruit trees, dividing the wood into two nearly 



Fig. 164. — Unpruned apple tree, with head too dense to admit light. 



equal parts are objectionable, since one or the other 

 part is very likely to split down under the weight of a 

 heavy fruit crop. 



Main branches inclined to split down may sometimes 

 be prevented from doing so by twisting two smaller 

 branches together, to form a connection between them 

 (Fig. 166). The branches thus twisted often grow to- 

 gether, forming a tie of great strength. A main branch 



