Influence of Rootstocks on Vegetative and Generative Characteristics of the Apple Cultivar 'Topaz' According to Organic Production Conditions in Eastern Austria

摘要

In autumn 2008, in the research orchard of the University of Natural Resources and Life Sciences in Vienna, the apple cultivar 'Topaz' was planted on the rootstocks M9 (clone T337) with and without 'Rubinola' as interstem, M26, M7 grafted at 25 cm and at 55 cm respectively, M111 and 'Bittenfelder seedling', trained as spindles and tested for eight years according to organic production rules. The trees on seeding grew very vigorously, followed by MM111 and M7 normally grafted; the M7 highly grafted trees showed less vigor, comparable with M26, while the trees on M9 with and without interstem grew very weakly. Tree losses were only observed on M9 without interstem. The highest yields per hectare were found on M7 normally grafted, followed by M26, M7 highly grafted and M9 without interstem. M7 highly grafted showed the highest single fruit weights, followed by MM111, at the other end were M9 with and without interstem, and M26. The rootstock M7 grafted at 55 cm combines a medium growth with high yield and good fruit quality and therefore can be recommended for dry areas like our site. M9 without interstem showed a higher specific yield and fruit firmness after storage compared to the variant with interstem. Whether these advantages for 'Topaz' on M9 can be combined with a higher grafting height as effective preventive method to control Phytophthora cactorum, has to be examined in further research.