For three years (2019–2021) in the north-west of the Volgograd region, in the system of ecological variety testing, corn hybrids of various groups of ripeness of selection of Russian breeding institutions were studied, from the early group, FAO 100-139, to the medium-late FAO 300. In different humidification years, the dependence of the corn grain yield and harvesting humidity on the SCC was established. In the dry year 2020, GTK – 0.47, there was the lowest yield in all groups of ripeness. With an increase in the ripeness group, the grain yield increased slightly: FAO 100–139 (2.6 t/ha), FAO 140–169(2.8 t/ha)…. FAO 200–249 (3.6 t/ha). The same pattern persisted in the moderately dry year 2019, GTC - 0.83, in the FAO group 100–139 (3.8 t/ha) to a maximum value of 5.5 t/ha of FAO 250–299. In the wet year 2021, GTK -1.8, the yield of hybrids varied from 4.8 t/ha of FAO 100–139, to the maximum value in the FAO 200–249 group of 6.3t/ha. It was revealed that in a dry year harvesting humidity in the early ripeness groups was low from 13.9% - 16.3%, with an increase in the maturation period from FAO 170–199 to FAO 300, the value of this indicator increased in direct progression, from 17.9 to 22.4%. In the moderately dry, 2019 harvest humidity was higher: FAO 100–139 (15.4%) to .. FAO 300 (24.6%). In the wet year 2021, humidity increased with an increase in the maturity groups of FAO 100–139 16.0% ... to 24.0% of FAO 300. It was noted that the breeding index for all groups of ripeness in a dry year was lower than in moderately dry and wet years. During the three years of research, the highest index value was in the FAO 100–139 group (2.5), in the ripeness groups of FAO 140–169, FAO 170–199, FAO 200–249 (2.3). In later blocks, the coefficient was lower.., FAO 250–299 (2.2), FAO 300 (2.1).