The formation of maize grain yield depends on the method of sowing and the density of the plants standing in the Northern Steppe of Ukraine

Abstract

Topicality. In the context of global warming and climate changes, it is important to substantiate, develop and implement agrotechnical practices to mitigate the negative effects of drought, heat and soil moisture deficit. The solution to these problems is to find ways to optimise the growing conditions of maize (Zea mays L.), using the adaptive properties and agrocenotic resistance of new hybrids to adverse environmental stressors with rational management of the growing season and agroclimatic resources of soil and ecological zones. Sowing methods and plant density, as well as other technological factors, play an important role in the complex of zonal agrotechnical practices. Maize plants demonstrate considerable biological plasticity in interaction with environmental conditions. The life support processes of maize plants depend on ecological changes caused by the quantitative and spatial placement of maize plants in the crop. The variability of the size and configuration of the individual plant nutrition area is limited primarily by the plant's requirements for environmental factors that ensure their normal growth, development and high productivity. Purpose. The research was aimed to identify the peculiarities of plant growth and development, as well as the formation of maize grain yield depending on the method of sowing and plant density in the Northern Steppe of Ukraine. Materials and Methods. The research was carried out at the Experimental Farm "Dnipro" of the State Enterprise of the Institute of Grain Crops of NAAS. The soil was ordinary low-humus full-profile chernozem. The mid-early maize hybrid DN Stiah was sown with row spacing of 30, 45 and 70 cm at plant density of 40, 50, 60 and 70 thousand plants/ha, fertiliser background – N60P45K45. Results. Sowing methods and plant density influenced the structural elements of the yield and maize grain yield. In 2019–2021, the highest average maize yield (11.13 t/ha) for factor A (sowing method) was obtained by sowing with row spacing of 30 cm. Increasing the row spacing to 45 and 70 cm led to a decrease in the grain productivity of the maize hybrid DN Stiah by 0.21 and 0.75 t/ha (i.e. by 1.9 and 6.7 %), respectively. For factor B (planting density), the highest average grain yield (11.03 and 10.95 t/ha) was obtained at a planting density of 60 and 50 thousand plants/ha, respectively. Conclusions. In the face of resource constraints, narrower row spacing in maize cultivation may have the potential to increase the level of realisation of hybrid productivity potential. Key words: maize, method of sowing, plant density, biometric indicators of plants, individual productivity of plants, structural elements of yield, grain yield