Evaluation of ornamental traits of apple trees from the collection of I. V. Michurin Federal Scientific Center

Abstract

Ornamental species of apple trees have gained large popularity in landscape design. The long-term work of Russian breeders has resulted in the selection of a number of ornamental apple-tree forms; however, insufficient attention has been paid to their practical implementation. At present, the Russian market is mainly represented by European varieties, which are unstable to the harsh conditions of Russian regions. The creation of adaptive varieties of ornamental apple trees with high aesthetic characteristics appears to be a relevant research task. In this work, ornamental apple tree forms for use in landscape design are evaluated using the methodology developed by V. V. Vasekha et al. (2017). Studies were conducted in the 2015-2022 period in experimental plots located in Michurinsk, Tambov Oblast. Research objects included trees planted in 2004 with a planting scheme of 6×2 m using 54-118 rootstocks. Depending on the genotype, the bud color was found to vary from white (M. sachalinensis), bright red (M. floribunda), and purple (M. purpurea pendula, Jay Darling, etc.). The new forms 7-13, 7-29, 4-100, and Nikas were characterized by large flowers over 35 mm in diameter. The leaf color varied depending on the season, from purple and red-purple in spring to green in autumn, which was typical of the majority of the studied genotypes. In summer, the genotypes having purple leaves turn red-green with the exception for the Royalty variety and M. purpurea var. aldenhamensis and M. purpurea species, whose leaves remain red until autumn. Fruits of ornamental apple trees are small, from 8 to 35 mm in diameter. Such varieties and forms, as Royalty, Profusion, M. sargentii, M. purpurea, M. floribunda, M. sachalinensis, M. Nikita floribunda, Jay Darling, Altaiskoe bagryanoe, M. floribunda, Nikas, 7-29, 7-13, and 4-100 are characterized by fruits up to 15 mm in diameter with high aesthetic characteristics. Nikas, 7-29, 7-13, and 4-100 have a columnar crown habitus, which significantly increases their ornamental value.