The influence of agrometeorological conditions on grain yield of spring barley in the conditions of Middle Volga region

To determine the influence of climatic conditions on the grain yield of spring barley, 18 varieties of different scientific institutions of the Russian Federation were used to assess the plasticity and stability of varieties. The research was conducted from 1998 to 2018 on the basis of Samara research Institute. Climatic conditions in the years of research varied significantly. The most favorable for the growth and development of plants were 1999, 2003, 2004, 2007, 2017. In these years, during the growing season there was sufficient moisture (hydrothermal coefficient = 0.96-2.10). The amount of precipitation ranged from 136.8 to 207.2 mm, and the average temperature did not rise above 20.3-21.8 °C. In 2017, the maximum grain yield was observed for all years of research (40.0 - 48.8 с/ha). Poor water supply was in 1998, 2009, 2010, 2015, and 2016. On average, for the studied years it was found that the period of earing-full ripeness was characterized by an increased temperature regime and a large amount of precipitation compared to the period of germination-earing. The average air temperature was 21.7 °C, with fluctuations depending on the year 19.1-24.9 °C. Average rainfall ranged from 3.2 to 163,4 mm. of the hydrothermal coefficient amounted to 0,05-1,41. The correlation analysis revealed that the duration of the period of earing - full ripeness positively correlates with the grain yield (r=0,385). Marked by high contingency in the amount of precipitation (r=0,536) and hydrothermal coefficient (r=0,609) grain yield during the period of germination-earing and the lack thereof, during the period of earing-full ripeness, as well as a negative effect of mean temperature on grain yield in the period of germination-earing (r=-0,530) and heading-full maturity (r=-0,536). Study on the varieties in the nursery ecological testing has helped to identify varieties with different norm of reaction to changing conditions in the external environment. The varieties Berkut, Donetskiy 8, Agat, Cozak, Batik are distinguished by high grain yield (24.0-25.3 с/ha) and optimal parameters of adaptability (bi=0.96-1.05; S²=1.07-4.61; Hom=1.02-1.22).