SPEEDS OF SPRING WHEAT GROWTH AND DEVELOPMENT DEPENDING ON HYDROTHERMAL CONDITIONS
Studies were conducted to study the effect of air temperature and the amount of precipitation on the growth and development of spring wheat plants. Analysis and quantitative description of the dependence of the duration of interphase periods was carried out by methods of correlation and regression analysis, changes in the duration of periods by calculating the coefficient of variation. For analysis, we used the results of long-term field observations (2014-2019) over the time of the onset of phenological phases in spring wheat varieties of the mid-ripe group in the Ural steppe, as well as published data of Davlekanovskiy GSU of the Republic of Bashkortostan for 1993-2016. An increase in temperature during all periods of vegetation accelerates the growth and development of plants, an increase in rainfall, on the contrary, slows down these processes. The change in hydrothermal conditions most strongly affects the duration of tillering - heading and heading - waxy ripeness periods. The coefficient of variation of their duration is 26.9 and 28.7, respectively. With an increase in air temperature by 1°C in the range of 11.3 ... 20.50С, the tillering-heading interfacial period decreases by 0.408 days, and the ripening of spring wheat grain (at a temperature of 10.7 ... 24.2°C) is accelerated by 0.424 of the day. An increase in precipitation by 10 mm in the range of 1.0 ... 126.2 mm slows the onset of heading by 0.39 days, waxy ripeness of grain (with a total of 0 ... 131.1 mm) - by 0.40 days. Statistical models of the dependence of the duration of interphase periods of growth and development of spring wheat plants on the amount of precipitation and average daily temperature can be used to predict the calendar dates of the onset of phenological phases and the operational adjustment of technological operations to care for sowing