GROWTH REGULATORS FOR INCREASING THE SEED PRODUCTIVITY OF HEAD CABBAGE PLANTS AT THE REPRODUCTIVE STAGE OF DEVELOPMENT

Abstract

Introduction. Belonging to different types of cabbage varieties, varietal types and maturity groups requires constant improvement of varietal technologies of seed cultivation. One of the effective methods of solving this problem is the use of growth regulators. Analysis of recent researches and publications. One of the effective methods of increasing the seed productivity of selection-valuable lines, varieties and F1 hybrids of head cabbage is the use of growth regulators. Scientific publications note the existence of certain differences in the growth response of different genotypes of white cabbage to treatment with regulators. One of the ways to overcome this problem is the creation of composite preparations, which would consist not of one biologically active substance, but of several, most susceptible to the realization of the genetic potential of cabbage-desert plants in terms of seed productivity and sowing qualities of seeds. Such compounds include salicylic acid, which, being an endogenous phytohormone, participates in the formation of plant resistance to biotic and abiotic stressors. The most diverse functions related to the derepression of development genes are performed in the plant organism by the growth regulator - gibberellic acid (GA3). Therefore, taking into account the constant changes in environmental stress factors, the issue of preserving the stable realization of the genetic potential of cabbage plants in relation to their seed productivity remains relevant and requires the planning and development of appropriate measures. One of the options for solving this issue is the synthesis of biologically active substances and the creation of composite preparations based on them, which include salicylic acid, gibberellic substances and other growth regulators. Purpose. To conduct an analysis of the regulatory properties of composite preparations of biologically active substances for their prospective use in the technological processes of growing cabbage seeds as growth regulators capable of increasing the seed productivity of cabbage plants in the reproductive stage of development. Methods. The work studied two composite preparations DSK-1A and DGURSK, which, in addition to other components, contained regulators of phytohormonal action. Biotests of the preparations were carried out on 3 varieties of cabbage (Kharkivska zimova, Yaroslavna, Paleta) of domestic breeding. To determine the regulatory activity, a single treatment of the root system of the queens with the tested preparations DSK-1A and DGURSK was carried out before planting in field conditions after the completion of the vernalization phase, which lasted in the spring-winter period. In the experiments, two statistical indicators were determined – “arithmetic mean weight of seeds from one cabbage seed” and “weight of 1000 seeds”. The calculation of the results of the experiment was carried out using the methods of variational statistics. Results. Evaluating the effect of the tested composite preparations, one should note their high efficiency in the formation of high-quality seed material of head cabbage. Compared to the absolute control, the reaction of reproductive plants of all three selected varieties of head cabbage resulted in an increase in the yield of seed mass from one seed plant by 36.30–57.47%, and the mass of 1000 seeds by 15.64–39.55% in the case of application of the drug DSK-1A. The regulatory effect of the drug DGURSK was also effective on two varieties, Paleta and Kharkivska zimova. Relative to the absolute control, the increase in the mass of formed seeds from one plant was 56.73–63.70%, but for the variety of Yaroslavna white-headed cabbage, this drug was not effective, which, presumably, can be related to the specific reaction of this variety to the action of the drug and the need to reduce his working concentration. On the formation of the weight of 1,000 seeds of a certain variety of head cabbage, the drug DGURSK had a generally consistently high effect, which was reflected in a statistically significant increase in the "weight of 1,000 seeds" indicator by 16.95–25.38% compared to the absolute control. All other modifications of the method of pre-planting treatment of head cabbage queens revealed a high dependence on varietal response. Discussion. As a result of the use of composite preparations of biologically active substances, it was possible to increase the seed productivity of cabbage plants, while minimizing the negative impact of varietal reaction to growing conditions.