Analysis of Quality Indicators in the Grain of Mid-late and Late Hybrids of Maize (<em>Zea mays</em> L.) in Bulgaria

Purpose: Maize is an important food and forage crop with a high nutritional value, primarily used as feed for farm animals. The chemical composition of maize grain plays a significant role in animal productivity. The study aimed at analyzing the quality parameters such as protein, oil, starch, fibre and ash in mid-late and late hybrids of maize, specifically: i) FAO 500-599 (Kneja 560, Kneja 564, Kneja 570A, Kneja 572 and KXC1395) and ii) FAO 600-699 (Kneja 648, Kneja 649, Kneja 650A, Kneja 650 and Kneja 683).Research Method: The plants were grown in the field without irrigation and NIR spectroscopy was used for analyses. The Pearson correlation coefficient was used to measure the strength and direction of the linear relationship between variables.Findings: The content of the parameters studied varied depending on the vegetation group. Among the mid-late hybrids, Kneja 560 exhibited the highest protein content (10.49%), while among the late hybrids, Kneja 648 had the highest both protein (11.63%) and starch content (68.61%). Ash content was the most variable trait, with a coefficient of variation of 9.714% for mid-late hybrids and 17.183% for late hybrids. The Pearson coefficient indicated a high correlation between ash content and fiber content in hybrids from both maturity groups, with r=0.778 for mid-late hybrids and r=0.949 for late hybrids.Value: The main chemical composition (excluding starch) was considered more greatly balanced in the grain of late hybrids of maize.