INFLUENCE OF HYDROTHERMAL CONDITIONS ON THE PASSAGE OF VEGETATION PHASES OF AMARANTH VARIETIES DEPENDING ON FERTILISER RATES

Abstract

Plant growth, development and yield formation are most dependent on five environmental factors: heat, moisture, light, air and mineral nutrients. The first four together form agrometeorological resources. Hydrothermal factors, such as precipitation, temperature and their distribution during the growing season, have the greatest impact on yields. The research on the peculiarities of the phenological phases of growth and development of amaranth plants was conducted at the experimental field of the Department of Plant Production Technologies of the Lviv National University Environmental during 2020–2023. The main factors influencing the growth and development of amaranth plants under conditions of sufficient moisture in the Western Forest-Steppe were determined. The duration of the growing season was determined by the varietal characteristics of the studied amaranth varieties. Increased air temperature accelerated the passage of vegetation phases of amaranth varieties. The longest inter-phase period of sowing-sowing (ВВСН 01-10) lasted 21 days in 2020 at a temperature of 10.8°C in May. The passage of the following phases of the amaranth vegetation varied depending on the rates of mineral fertiliser application and varietal characteristics of the studied varieties. The correlation coefficient between the level of fertilisation, variety and duration of the germination-budding period (ВВСН 11-50) was r = 0.93. The increased air temperature in July (21.7°C) contributed to a reduction in the duration of the budding-flowering period (ВВСН 51-60), depending on the fertiliser rate and the year of research. This is confirmed by the results of statistical analysis: a significant effect of air temperature on the passage of the budding-flowering period (ВВСН 51-60) was found, the correlation coefficient r = 53. Fertiliser rates had the greatest impact on the onset of the ripening phase and the duration of the growing season. The correlation coefficient between the level of fertilisation, variety and duration of the flowering-ripening period (ВВСН 61-89) and the length of the growing season was r = 0.88 and r = 0.97, respectively.