When the tiers were formed, 6 or 7 limbs were retained because 

 the extra limbs provided leaf surface and permitted a choice 

 when selecting permanent limbs. When the extra limbs were removed, 

 limb selection was made to maximize the vertical spacing of the 

 permanent limbs. The extension growth from the headed leaders 

 was longer than that on the non-headed leaders in 1976 and 1978 

 but not in 1977 (Table 2.) The extension growth of the central 

 leaders was not measured in 1979. 



Figure 6. A tree on which no heading cuts were made on 1-year-old 

 shoots. Photographed May, 1980. 



