The influence of hydrothermal conditions of the Kirov region on the productivity and quality of grain of spring soft wheat varieties of different ripeness groups

Abstract

Meteorological conditions were monitored for the period "May-August" in the Kirov region (Volga-Vyatka region) from 2008 to 2022. An increasing trend of the sum of precipitation and hydrothermal coefficient (НTC) values and a descending trend of the sum of effective temperatures was established. By the example of early-ripening (Iren, Bazhenka) and middleripening (Priokskaya, Simbirtsit, Margarita, Kamenka) varieties of spring wheat, the level and direction of variability of the main agronomic traits by changing the values of the НTC have been determined. In early-maturing varieties with an increase in the НTC of the growing season the content of protein and gluten in the grain significantly decreased, and the following increased: yield, duration of vegetation, plant height, ear density, mass of 1000 grains, density of the productive stem, the nature of the grain and the indicator of the gluten index. The elements of ear productivity were maximally expressed in the years optimal in terms of moisture. The reaction of medium-ripened varieties was similar according to the greater number of traits, except for the number of grains per ear, the weight of the grain per ear and the plant, the nature of the grain. By means of the correlation analysis, the influence of meteorological factors on the development of traits of spring wheat both for the entire growing season and for individual months has been studied. A high dependence of the duration of the growing season and the protein content in the grain on the sum of effective temperatures for May-August (r = 0.64...0.77) was revealed. The amount of precipitation made a significant contribution to the formation of traits only in critical phases of plant development. The analysis of regression equations obtained using 11 variables (weather factors by months) with a time sample size of 15 years showed that an increase in the amount of precipitation in June by 10 mm led to an increase in yield by an average of 0.13...0.14 t/ha, and a decrease in the average daily temperature of August by 1 °C provided an increase in yield by 0.23...0.26 t/ha. The duration of the growing season decreased in June by 2.2...2.4 days with 1 °C increase in the average temperature; in July – by 2.3...3.0 days; in August – by 1.3 days. The protein content in the grain most of all depended on the average daily temperature in June, with of 1 °C increase the amount of protein raised by 0.85...0.87 %.