An assessment of clonal rootstocks of an apple tree in conditions of the steppe zone in the Trans-Volga-Ural region

Abstract

Small stature forms of clonal rootstock in combination with recognized and appreciable varieties promote to increase productivity in one and half-two times from a unit of the area. New clonal rootstocks are characterized by increased winter- and drought-resistance, enabling the growth of rootstocks’ adaptiveness to the Trans-Volga-Ural region’s extreme conditions. Conditions of the region are characterized by low temperatures in the winter to −40 – −42°C. A deficit of precipitation and high temperatures to + 40-+ 42°C is noticed in the summer. Our research aims to study the adaptive ability of groups of clonal rootstocks of an apple tree above 30 forms of selection in Central Russia, Povolozhie, and foreign countries. Laboratory-field methods “Program and methodology of selection of fruit…” (1999) were used to estimate the adaptiveness of rootstock forms, including drought-resistant kinds. Forms: 71-3-195, MM 106, Baba-arabskaya Adzhi, Ural 5, Ural 3, elite forms 6 – 9 H, 5-4-13 are characterized by high preservation (80-90%) among clonal rootstocks for the years of the study. Forms: Ural 5, 62-223, 54-118, Ural 2, elite forms 4-5, 4-19-3, 76-23-2, К-2, 71-7-22, Don 70-456 are characterized by drought-resistance. Rootstocks of semi dwarves: 64-134, Ural 6, Ural 2, elite forms 5-4-13, 4-19-3, 5-19-1, dwarfish forms are: 71-7-22, 58-238, 64-134, 62-14, К-2, Don 70-52, have received 4-5 points according to the plantation state. All kinds listed above showed high adaptive ability in extreme conditions of the Trans-Volga-Ural region and were initial material to establish intensive plantings.