Optimization of the parameters of quantitative traits of maize hybrids used for grain

The studies were carried out in 2015–2017 at the FSBSI “Agricultural Research Center “Donskoy” in order to determine the opti­mal values of quantitative traits, the combination of which allows forming the maximum yield for hybrids of grain use in arid conditions. The 96 maize hybrids were the initial material which were studied for grain productivity, plant height, height of ear attachment, length of the vegetation period and of the period from germination to ear flowering. The presence, strength and direction of correlation between grain productivity and quantitative characteristics have been established. There has been identified a weak positive correlation between the grain productivity and plant height (r = + 0.10…+0.23). Maize hybrids for grain use should be of medium height with an optimal value of the trait of 220–250 cm. The grain productivity had an average in 2016 (r = + 0.49) and a weak in 2015 and 2016 (r = + 0.05; r = +0.17) dependence on an ear attachment height. The optimal values of the trait were 80–95 cm. The nature of the dependence between grain productivity and the length of the vegetation period greatly differed through the year of study. In 2016 an average positive correlation was r = + 0.52; in 2015 and 2017 there was a weak negative correlation r = –0.14, r = –0.24. Through different years, the hybrids of various groups of ripeness formed the maximum grain productivity of 5.0–5.5 t/ha. The hybrids of the middle-early group of ripening, as well as the early-ripening and middle-ripening hybrids had an advantage before the middle-early group slightly differing in the length of the vegetation period. The optimum length of the vegetation period is 97–110 days, the period from germination to ear flowering is 53–61 days.