including M.9, Mark, and M.26. Now, more 

 than fifty percent of all trees being planted in 

 New England are on fully dwarf rootstocks. 

 This trend has been seen throughout the apple 

 growing regions of North America. Throughout 

 this period when clonal rootstock material be- 

 came more important to the apple industry, 

 knowledge of rootstock characteristics became 

 essential. 



To help evaluate both new and old clonal 

 rootstock material, the NC-140 Technical Re- 

 search Committee was established. A group of 

 scientists fi"om various universities across the 

 country formed this committee in association 

 with the U. S. Department of Agriculture. Indi- 

 viduals fi-om five Canadian provinces cooper- 

 ated in the formation and participate in the 

 execution of the responsibilities of this commit- 

 tee. One of the first major plantings by the 

 committee included Starkspur Supreme DeU- 

 cious on 0.3 (Ottawa 3), M.7 EMLA (the EMLA 

 designation suggesting that the latent viruses 

 were removed fi-om the mother plant), M.9 

 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC.9 

 (later, a virus indexed version was named 

 Mark), and OARl (Oregon Apple Rootstock 1). 

 These combinations were included in random- 



ized complete blocks, each with five replications 

 at 27 sites in the U. S. and southern Canada. 

 Most sites removed their plantings after the 

 tenth growing season, i.e. after harvest in 1989. 

 In this article, we report on the Massachusetts 

 portion of this trial, including four years of data 

 beyond the termination of the joint trial. 



Materials & Methods 



Trees were planted at a spacing of 11.5 x 18 

 feet in the spring of 1980 at the University of 

 Massachusetts Horticvdtural Research Center 

 in Belchertown. Trees were trained as central 

 leaders, using minimal pruning. Some contain- 

 ment pruning was required when trees reached 

 maturity. Stakes were added for support only 

 when trees leemed past 45 degrees. Standard 

 pest and fertility management practices were 

 used. Tree size and yield were measured annu- 

 ally; however, trees were not allowed to finiit 

 until the fourth growing season (1983). 



Results & Discussion 



Table 1 gives the trunk cross-sectional area, 

 height, and spread of these trees after the four- 

 teenth growing season (1993), and Figure 1 



Fruit Notes, Spring, 1994 



