MATURITY GROUP AND DENSITY OF CORN PHYTOCENOSY UNDER CLIMATE CHANGE

Abstract

The problem facing agricultural production when growing grain corn is establishing a differentiated density of modern hybrids in specific soil and climatic conditions in order to realize their genetic potential for productivity. Modern corn hybrids differ significantly from each other in a complex of biomorphological and economically valuable traits; are characterized by different reactions to environmental factors, agrotechnical conditions; have different degrees of adaptation and resistance to biotic and abiotic environmental factors. Therefore, it is very important to establish the regularities of the formation of the structure of agrocenoses of modern corn hybrids depending on the density of plant stands. During 2022–2024, we conducted research in the conditions of Kholodny Podillia of the Western Forest-Steppe of the Ternopil region on the reaction of corn hybrids of different maturity groups to plant density. The results of the research show that reducing the area of plant nutrition due to increasing the stem density from 60 to 90 thousand/ha leads to a decrease in individual plant productivity, a slight decrease in the mass of 1000 grains and an increase in grain moisture during the harvest period. Despite the decrease in the structure of corn grain yield in the thickened agrophytocenosis, the early-ripening hybrid Anovy KS (FAO 220) ensured the maximum realization of genetic potential at a sowing density of 80 and 90 thousand/ha, respectively 11.24 and 11.15 t/ha. The mid-early hybrid Databaz (FAO 280) ensured the maximum yield at a stem density of 70 and 80 thousand/ha – 11.92 and 11.77 t/ha. The mid-ripening hybrid UNI 3511 (FAO 340) on average over three years ensured the highest yield – at the level of 12.83 and 12.81 t/ha – at a sowing density of 60 and 70 thousand/ha.