Influence of plant density on the yield of corn hybrids of different groups of ripeness

In the survey the influence of the density of corn plants on the grain yield and the main biometric indicators in the conditions of the southern forest-steppe of the Omsk region was tested. The object of research is 9 maize hybrids of the All-Russian Scientific Research Institute of Corn with a FAO index (conditional index of early maturity of the Food and Agricultural Organization) from 130 to 250: Sibirsky 135, Mashuk 140, Mashuk 150, Mashuk 171, Katerina SV, Mashuk 185, Newton, Mashuk 220, Mashuk 250. All hybrids are included in the State Register of Breeding Achievements from 1999 to 2017. The article presents the results of phenological and biometric observations: grain yield, grain harvesting moisture at plant density from 70 to 90 thousand plants/ha for hybrids with FAO 130-180 and from 60 to 80 thousand plants/ha for hybrids with FAO 210-250. In all hybrids, an increase in the duration of the interphase period “shoots-flowering of the cob” was established during the thickening of crops. The yield of grain with a moisture content of 14% in the experiment ranged from 5.29 to 7.02 t/ha. Hybrids with FAO 130-180, with the exception of Mashuk 140, gave the maximum grain yield at a plant density of 70 thousand plants per 1 ha, Newton and Mashuk 220 - at a plant density of 80 thousand plants/ha. Mashuk 250 did not have time to realize the yield potential due to the short growing season. When choosing the density of corn plants in the Omsk region, it is necessary to take into account not only the FAO index, but also the genetic characteristics of specific hybrids: plant height, tendency to form several cobs, and tillering capacity.