Analysis of dimensional characteristics of maize and sunflower seeds

The efficiency of agricultural machinery used in the cultivation of row crops – most notably sunflower and maize – depends significantly on how well the operating parameters match the physical and dimensional characteristics of the seeds. This study aims to analyze the dimensional properties of seeds from modern sunflower and maize hybrids (varieties). The research involved measuring the primary dimensions of twelve maize hybrids and seven sunflower varieties/hybrids recommended for the Central Black Earth and North Caucasus regions of the Russian Federation, followed by statistical analysis. The findings indicate that maize seeds have average dimensions of 11.0 mm (length), 8.4 mm (width), and 5.1 mm (thickness), with inter-hybrid variability ranging between 8.1% and 9.7%. Correlation analysis revealed no significant relationship between length and width or width and thickness; however, an inverse correlation was observed between seed length and thickness. Sunflower seeds exhibited average dimensions of 11.7 mm, 6.1 mm, and 3.8 mm for length, width, and thickness, respectively, showing a direct correlation across all primary dimensions. For process modeling purposes, maize seeds can be approximated as ellipsoids of revolution with the axis of rotation corresponding to thickness, while sunflower seeds are best represented as ellipsoids rotating about their longitudinal axis. These dimensional characteristics are applicable for selecting rational parameters of seed-cleaning screens, grading machinery, indent cylinders, and the diameters of metering elements in precision seeders.