ASSESSMENT OF CRITICAL PERIODS OF GROWTH AND DEVELOPMENT OF OILSEED RADISH PLANTS (RAPHANUS SATIVUS L. VAR. OLEIFORMIS PERS.) ON THE BASIS OF CHLOROPHYLL FLUORESCENCE INDUCTION METHOD

The article highlights the results of studying critical periods in the phenological development of oilseed radish varieties based on the use of basic indicators of the chlorophyll fluorescence induction curve (initial fluorescence (F0), plateau zone fluorescence (Fpl), maximum fluorescence (Fm), and stationary fluorescence (Fst). This complex was applied to oilseed radish plants of three varieties – ‘Rayduga’, ‘Zhuravka’ and ‘Lybid’ with the presentation of results for the variety ‘Zhuravka’ due to the similarity of the obtained data. phases of growth and development of oilseed radish: cotyledon phase, budding phase, flowering phase, green pod phase and yellow-green pod phase. Based on the use of a single-beam porous fluorimeter ‘Floratest’, developed by the Research and Engineering Center of Microelectronics of the Institute of Cybernetics named after V.M. Glushkova (Ukraine) formed curves of chlorophyll fluorescence induction (CFI) in the mode of 90-second fixation of parameters for each phenological phase of oilseed radish plants.The system of graphical display of regularity of formation of basic indicators of CFI curve within the main phenological phases is analyzed and generalizations and conclusions concerning dynamics of course of photochemical physiological processes of photosystem II of plants are made. in the process of phenological stage changes and the corresponding processes of morphogenesis of oilseed radish plants. The dynamics of exogenous and endogenous factors on the formation of indicators of assimilative activity of oilseed radish plant photosystems is analyzed on the basis of analysis of position and changes in time of main points of CFI schedule and substantiated obtained indicators with predicted physiological state of plants and possible assimilation activity. The values of baseline and indication indicators of CFI curve are compared to the main phenological phase of flowering, which is defined as the baseline in ensuring the realization of the productive potential of oilseed radish plants.