Agrobiological substantiation of the density of amaranth agrocenosis in the conditions of the Southern Steppe of Ukraine

Abstract

Goal. To determine the most effective, adapted to specific soil-climatic conditions, density of amaranth agrocenosis for grain production in conditions of the arid Southern Steppe of Ukraine. Methods. Meteorological observations and the measuring-weight method for determining yields. To determine the probability of the obtained results, the difference between the studied parameters and characteristics was determined using the method of analysis of variance. Mathematical processing of the results was carried out using the AgroStat platform. For research, amaranth seeds of varieties of domestic selection Kharkivskyi-1 (universal) and Lera (grain) were chosen. Results. The study was conducted in 2022–2024 in the Odesa region in the climatic conditions of the Danube Steppe of Ukraine. Yield of amaranth grain of Kharkivskyi-1 and Lera varieties for 2022–2024 years was formed under the influence of weather conditions and the available density of plant standing. The best average yield of amaranth grain was obtained in 2022 (2.44 t / ha for Kharkivskyi-1 variety, and 2.70 t/ha for Lera variety). 2024 was characterized by extremely unfavorable weather conditions, which led to a significant decrease in the yield of both varieties. An increase in the density of amaranth agrocenosis from 90 to 150 thousand pieces/ha contributed to an increase in its productivity per unit area, which made it possible to obtain an average of 2.15 tons/ha of amaranth grain of the Kharkivskyi-1 variety, and 2.32 tons/ha of the Lera variety. Further thickening of crops led to a decrease in the productivity of both varieties. Conclusions. The highest amaranth grain yield (2.16 t/ha) during 2022–2024 studies was obtained in the Lera variety. The variety Kharkivskyi-1 in conditions of arid Southern Steppe was less fruitful, with a productivity level of an average of 2.00 tons / ha of grain. The highest grain yield was obtained at an agrocenosis density of 150 thousand units/ha (2.24 t/ha). The proportion of influence of factor A (grade) in the experiment was 23.66%, and factor B (agrocenosis density) was — 72.87%.