АДАПТИВНОСТЬ НОВЫХ ПОДВОЕВ ЯБЛОНИ СЕРИИ СТ К СТРЕССАМ ЛЕТНЕГО ПЕРИОДА ВЕГЕТАЦИИ

Abstract

Within the framework of the joint program of the FSBSI NCFSCHVW and the Stavropol experimental station of horticulture – Branch of Federal State Scientific Institution «North-Caucasian FNAC», for the breeding of apple tree rootstocks, hybrids of apple-tree rootstocks of the ST series were assessed in terms of their adaptability to the conditions of the summer vegetation period in the central subzone of the Prikuban horticultural zone (Krasnodar city). The resistance of apple rootstocks to the stresses was determined by the water content and water-holding capacity of the leaves, which characterize the ability of plants to maintain water homeostasis during stress. In the nursery of offspring rootstocks, the drought resistance of apple tree rootstocks was determined by the laboratory-field method during the period of the greatest intensity of the water regime of plants. The zoned rootstock MM-106 was used as a control. The leaves of rootstocks CT 20-2 and CT 18-2 retained water better, in which the water loss for 2 hours of exposure was 28.3 and 30.3 % compared to 34.7 % for the control rootstock MM-106. The high water-holding capacity of the ST 20-2 rootstock was previously noted in the dry August 2020 – water loss in 4 hours was 31.5 % compared to 53.0 % for rootstock MM-106. The most productive were trees of the Prikubanskoye variety on rootstocks SK 2U, ST 20-4, 106-3, ST 13-3. The best specific productivity for five years of fruiting was in trees on rootstocks SK 2U, SK 5 and ST 13-3 hybrid (5.28; 4.74 and 4.22 kg/m2 ). Selected and recommended f or participation in breeding programs as a source of drought resistance rootstock ST 20-2 (MM-106 x M 9) and as a source of tree productivity in the garden, rootstock ST 13-3 (rootstock 58-250 x free pollination).