Variation of plant height and ear insertion height traits in short-season maize hybrids under the optimal and late sowing dates

Topicality. In light of the intensification of agriculture towards more rational utilisation of land resources and the growing season, given the importance of stubble and postcut fodder maize crops in fodder production and maize adaptability to the conditions of the Steppe zone, it is important to study the growth processes of maize under late sowing. Namely, the study of the influence of late sowing date on such traits as plant height and insertion height of the first productive ear for early ripening hybrids, the share of which in maize grain production is increasing. Purpose. To establish the most stable hybrid combinations by studying the variability of plant height and ear insertion height in early ripening maize hybrids under two sowing dates. Methods. Hybridization was used for developing hybrid material; laboratory and field method – to determine morphobiological traits of maize hybrids; measuring weight - to determine metric traits of plants; mathematical and statistical method – to determine the reliability of results, indicators of trait variability, and the correlation of traits. Results. The study of early ripening maize hybrids developed by crossing the most common germplasms under two sowing dates revealed that hybrids of heterotic models Iodent×Flint and Iodent×Mix had stably high values of the plant height trait at both sowing dates; hybrids of heterotic models Iodent×Flint and Iodent×Mix and Mix×Flint had stably high values of the insertion height of first productive ear at both sowing dates. Conclusions. We have identified the hybrid combinations DK4173SVZM×DK367, DK4172×DK367, MS381MV×DK367, MS555×DK367 (heterotic model Iodent×Mix), and DK4173SVZM×DK2073 (heterotic model Iodent×Flint), which were characterised by stably high values of the plant height trait, as well as the hybrid combinations DK4172×DK4538 (heterotic model Iodent×Flint), DK4172×DK367 (heterotic model Iodent×Mix), and DK2659×DK4538 (heterotic model Mix×Flint), which were characterised by stably high values of the insertion height of first productive ear at both sowing dates. The correlation between plant height and the ear insertion height of maize hybrids was confirmed for both sowing dates in all heterotic models studied. Key words: common maize, breeding, prematurity, plant height, ear insertion height, sowing dates, line, single-cross hybrids