Th e eff ect of Osmocote pro mineral fertilizer and plant growth regulators on the biometric parameters of clonal rootstocks 54-118

Abstract

Obtaining a standard planting material with a closed root system for establishing a basic mother plantations of clone apple clone processes using intensive technology was carried out in protected soil. During the growing season, modern mineral fertilizers and plant growth regulators were used. The aim of the research was to establish the effect of the combined use of plant growth regulators and a complex mineral fertilizer of prolonged action Osmocote Pro on plants of clonal rootstocks 54-118 with a closed root system when cultivated in protected soil. The factors of the experiment were doses of mineral fertilizer (0, 2, 4, 6, 8 gL-1 substrate) and plant growth regulators (IBA, gibberellic acid). It was established that the mineral fertilizer of prolonged action contributes to the realization of the genetic potential of the improved planting material of clonal rootstocks of apple trees to a greater extent than plant growth regulators. Plants with smaller sizes of the aboveground part gave the maximum increase (from 10 to 300 %), with an increase in the initial height of the aboveground part, the increase decreased, which allowed at the end of the season to obtain a leveled source material necessary for establishing basic mother plantations. The maximum increase, 310  % of the initial height of the aboveground part, was observed when Osmocote Pro mineral fertilizer was introduced into plant containers, a dose of 6 gL-1 of substrate and root treatment with plant growth regulator IBA. For plants with an initial height of the aboveground part of 21-40 cm, the greatest increase was obtained with the use of Osmocote Pro mineral fertilizer, a dose of 6 gL-1 of substrate, and treatment with IBA and gibberellic acid. The application of a dose of mineral fertilizer of 8 gL-1 of the substrate caused chlorosis of individual leaves and did not contribute to an increase in the height of the aboveground part of the plants. The maximum height-aligned planting material of clone rootstocks 54-118 was obtained with the combined use of Osmocote Pro mineral fertilizer 4 gL-1 of substrate by treatment plants of gibberellic acid, the coefficient of variation within the variant was 11.4 %.