The formation of crop yield of millet varieties depending on hydrothermal conditions

Studying the process of forming the yield of millet varieties in harsh natural conditions to create highly productive, adaptive varieties was not simple, but an actual task of the selectioner. The purpose of the research was to study the formation of the yield of millet varieties of different groups of ripeness depending on hydrothermal conditions of Samara Region. Millet vegetation conditions were different and could be described as follows: 2014 and 2015 years were more favorable; 2016-2018 were unfavorable. The yield of millet varieties fluctuated in the range of 1.36-3.00 t/hectare over the years; the coefficient of variation (CV) reached 31.5 %. The analysis of the effect of the sum of active temperatures on the yield of millet varieties indicated close inverse correlation in Povolzhskoe 80 variety (r = - 0.76, d = 57.8 %), average inverse - in Krestyanka variety (r = - 0.50, d = 25.0 %) and a weak direct in Rossiyanka (r = 0.27, d = 7.3 %) in the sweeping - full ripeness phase. Average inverse correlation relationship of all the varieties was observed for the whole vegetation period from shoots to full ripeness (r = - 0.55 ... - 0.62; d = 30.3 - 38.4 %). The influence of precipitation on the yield of millet varieties showed that there had been weak correlation between all millet varieties in the seedling - tillering and tillering - ear formation phases. During the ear formation - full ripeness phase and during the entire growing season from germination to full ripeness, an average direct correlation was observed in all the varieties (r = 0.44-0.51, d = 19.4-21.2 %) (r = 0.36-0.49; d = 12.9 - 24.0 %). The farmer is recommended to grow not less than two varieties of millet with different ripeness groups and responsiveness to the changes in environmental conditions.