on M.26 EMLA will be the least productive and those 

 on 0.3 or Mark will be the most (on a commercial ba- 

 sis). Finally, for trees on any of these rootstocks, fruit 

 size will be good. 



Rootstock evaluations which compare the relative 

 differences related to rootstock with different scion cul- 

 tivars are important. Although this study did not show 

 any significant variation in rootstock effects from scion 

 cultivar to scion cultivar, the whole study (over 1 8 sites) 

 does show some variation. Other studies also have 

 shown some significant variations, partially related to 

 incompatibilities. We have two other cooperative 



projects dealing with the potential for the interaction 

 between rootstock and scion cultivars. One was planted 

 in 1991, again in Belchertown, Mass. and Monmouth, 

 Me., including Pioneer Mac, Marshall Mcintosh, 

 Rogers Red Mcintosh, and Chic-a-dee Mcintosh on M.7 

 EMLA, Mark, M.27 EMLA, or M.26 EMLA. The 

 second will be planted in Belchertown and Monmouth 

 this spring and includes Rogers Red Mcintosh, Pioneer 

 Mac, Cortland, and Macoun on B.491 . B. 146, P.2, P.22, 

 V.l, V.3, B.469, R16, B.9, M.9, M.9 NAKBT337, or 

 Mark. These studies should help growers select the 

 best rootstock for the scion cultivars grown locally. 



22 



Fruit Notes, Spring, 1995 



