O. Callesen
Twenty rootstocks were tested for the apple cultivar 'Elstar' and 16 for 'Mutsu'. The goal was to compare winter hardy rootstocks of Polish and Russian origin with the industry standards, namely M.9, M.26 and MM.106. Clones of M.9 and M.26 were also included, together with newer rootstocks, such as Jork 9, Pillnitz 80 and Bemali.

The most promising rootstock in the test was J.9. It produced the highest yields, it was among the best for fruit size, it was among the highest in specific productivity and it had the highest fruit size index. P.16, which was less vigorous than M.9, also had a higher specific productivity than M.9 and may have potential despite its suckering. Differences between M.9 clones and M.26 clones were found.

Winter hardiness could not be tested, as no severe winters have been experienced since the trial's establishment.

Callesen, O. (1997). TESTING 20 APPLE ROOTSTOCKS. Acta Hortic. 451, 137-146
DOI: 10.17660/ActaHortic.1997.451.12

Acta Horticulturae