Dynamics of biometric indicators of maize plants under the influence of sowing rates and field productivity zones

Biometric indicators of maize are an important indicator of the effectiveness of agricultural technologies and reflect the adaptive response of crops to spatial heterogeneity of growing conditions. The aim of the study was to determine the effect of zonal productivity and sowing rates on the height and dry matter formation of maize in the early stages of organogenesis. Field studies were conducted in 2023-2024 within three field productivity zones: high, medium and low. Five sowing rates were varied, ranging from 65 to 85 thousand seeds/ha. The results of the studies show that the productivity zone had the main influence on the biometric parameters of plants, while the sowing rate had an additional but less significant effect. At the V2-V3 stage of corn development, the maximum dry matter content (up to 23.5%) was observed in the high-yield zone at a sowing rate of 70 thousand seeds/ha. In low-productivity zones, the indicators decreased to 15.5%. Plant height in this phase ranged from 22.5 cm in the high zone to 16.6 cm in the low productivity zone. In the early flowering phase (R1), a decrease in dry matter content was observed towards less productive zones: from 31.7% (high zone, 70 thousand/ha) to 25.3% (low zone, 85 thousand/ha) in 2023. Plant height varied from 252 cm in high-yielding areas to 143 cm in low-yielding areas. The biometric parameters of maize can be used as a reliable criterion for assessing the response of crops to differentiated technological techniques, which is a promising direction in precision farming systems. The use of zonally differentiated sowing rates allows for more efficient use of resources and optimisation of agricultural technologies for growing maize in fields with varying productivity