How Does B.9 Stack Up 

 Compared to M.9? 



Wesley Autio 



Department of Plant & Soil Sciences, University of Massachusetts 



In a previous article (pp. 22-25 in this issue), the 

 various M.9 apple rootstock strains were compared. 

 These were part of the 1994 NC-140 Apple Rootstock 

 Trial, with Gala as the scion. Budagovsky 9 (B.9) was 

 also part of that trial, planted in 1994 and maintained 

 for 10 years. 



In this brief article, the data for B.9, M.9 Fleuren 

 56 (the smallest M.9 strain in the trial), and M.9 Pajam 

 2 (the largest M.9 strain in the trial) are presented 

 (Figure 1). After 10 growing seasons, trees on B.9 

 were comparable in size to those on M.9 Fleuren 56 but 



significantly smaller than those on M.9 Pajam 2. Root 

 suckering from B.9 was lower than from M.9 Pajam 2. 

 Yield of trees on B.9 was comparable to trees on M.9 

 Fleuren 56 and lower than trees on M.9 Pajam 2. B.9 

 resulted in yield efficiency and fruit size similar to the 

 two M.9 strains. 



Over the 10 years of this trial, B.9 performed well, 

 producing a small M.9-sized tree with similar yield 

 characteristics. We now have 20 years experience 

 with B.9 and have no negative aspects of the rootstock 

 to report. 



96 



-S4- 



45 



36 



27 



18 



9 - 



-aso- 



iH 



300 ■ 



240 



180 - 



120 - 



60 - 



5 - 



2 - 



-4«e- 



150 - 



120 



90 



60 



30 - 



!#:: 



Trunk cross-sect, 

 area (cm2) 



Cumulative 

 suckers per tree 



Cumulative yield 

 per tree (kg) 



Yield efficiency 

 (kg/cm2 TCA) 



Average fruit size 



(g) 



Figure 1 . Trunk cross-sectional area, root suckering, yield, yield efficiency, and fruit size of Gala apple trees on 

 B.9, M.9 Fleuren 56, and M.9 Pajam 2, after 10 growing seasons. Bars with different letters are significantly 

 different at odds of 1 9: 1 . 



Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 



31 



