tips of branches or the central leader is called 

 apical dominance. Notching breaks apical domi- 

 nance and induces the bud to grow into a shoot. 



Notching has been recommended occasion- 

 ally over the years by nomologists, extension 

 personnel, and growers; however, it has never 

 become a widespread commercial practice be- 

 cause of erratic and unpredictable results. Fac- 

 tors that influence the effectiveness of notching 

 never have been studied thoroughly. We specu- 

 lated that the inconsistent results with notching 

 may have been due to a lack of understanding of 

 the factors that affect bud growth following 

 notching. A series of experiments were carried 

 out during four years to identify factors that 

 influence the response of young apple trees to 

 notching. 



All notching experiments were conducted at 



the University of Massachusetts Horticultural 

 Research Center between 1986 and 1990. 

 Notching was done using an ordinary hacksaw 

 blade. Buds were notched by placing the blade 

 immediately above a bud and drawing the blade 

 horizontally across the branch. In this way a 

 strip of bark about 1/16-inch wide above the bud 

 was removed on about one third of the circumfer- 

 ence of the branch (Figure 1). It is important to 

 remove all bark down to the wood in this strip. 

 The following sections describe the results 

 from several experiments which asked specific 

 questions about notching. 



Timing 



In 1986, a block of Redspur Delicious/ 

 MM. Ill was divided into 11 groups (replica- 



10 



Fruit Notes, Winter, 1992 



