Siemenperusrunkojen vaikutus omenapuiden satovaihteluihin

Authors

• Jaakko Säkö Maatalouskoelaitoksen puutarhaosasto, Piikkiö

DOI: https://doi.org/10.23986/afsci.71338

Abstract

At the Department of Horticulture annotations on the yearly crop of a number of different apple varieties. In this paper are given the crop records of certain trees, grafted upon Finnish seedling rootstocks of known origin for periods of 15—21 years from planting time onwards. The general management of all these trees, such as pruning, manuring, etc., has been uniform all the time. Although the material available was rather small, it was established that the seedling rootstocks used have not had any marked influence upon the productivity of the individual trees of one and the same variety. On the contrary, most of the trees have had very uniform total crops if the periods taken into consideration have been sufficiently long. The apple varieties which start to crop rather late, such as Sugar-Miron or Lepaan meloni, may show rather large individual variations during the first years of cropping (the period from 6 to 11 years). Later, when the trees reach full cropping age, the variation begins to diminish. Some early cropping varieties, such as Snygg and Harlamovsky, on the other hand, show a striking uniformity in the yields of the individual trees even during the first period. In general, it may be stated that despite the existence of much variation in the annual cropping of the individual trees, the records of total crops from the same trees for periods of several years remain fairly uniform, as has already been pointed out. Unfortunately it was not possible to make direct comparisons between the trees considered here and others grafted upon clonal rootstocks. Reference may be made, however, to Meurman's (1953) paper on the yield records of certain apple trees upon Mailing rootstocks grown in Finland. The individual trees in trials reported in that paper revealed a very high variability in yield, in spite of the hereditary uniformity of the clonal stocks used. The hardiness of the trees grafted upon Finnish seedling stocks appears to be distinctly better than that of trees upon clonal Mailing stocks in our conditions. Apparently this is one of the main reasons why relatively great variation exists between the cropping records of individual trees grafted on clonal stocks when compared with the greater uniformity of cropping present in trees grafted upon Finnish seedling rootstocks.