Research Highlights: The correlations between seed mass and the remaining physical properties were determined in selected fir species, and a method for seed sorting was proposed to promote uniform germination and emergence. Background and Objectives: Information about the variation and correlations between the physical properties of seeds is essential for designing and modeling seed processing operations such as seed separation. The aim of this study was to determine the range of variation in the physical properties of seeds in eleven fir species, and to analyze the correlations between these parameters to improve the seed sorting process. Materials and Methods: Terminal velocity, thickness, width, length, the angle of external friction and mass were determined in the seeds of 11 fir species. The measured parameters were used to calculate the geometric mean diameter, three aspect ratios, sphericity index and the specific mass of each seed. Results: The seeds of Sierra white fir where most similar, whereas the seeds of balsam fir differed most considerably from the seeds of the remaining fir species. In the majority of the analyzed fir species, seed mass was most strongly correlated with terminal velocity, followed by thickness. Conclusions: Fir seeds should be sorted primarily with the use of mesh sieves with longitudinal openings to obtain fractions with similar seed mass and to eliminate the need for dewinging.

Numerical models of bean seeds cv. Złota Saxa and yellow lupine seeds cv. Juno were generated with the use of a 3D scanner, the geometric parameters of seeds were determined based on the models developed, and compared with the results of digital image analysis and micrometer measurements. Measurements of seed length, width and thickness performed with the use of a micrometer, 3D scanner and digital image analysis produced similar results that did not differ significantly at α = 0.05. The micrometer delivered the simplest and fastest measurements. The mean surface area of bean seeds cv. Złota Saxa and yellow lupine seeds cv. Juno, calculated with the use of mathematical formulas based on the results of micrometer measurements and digital image analysis, differed significantly from the mean surface area determined with a 3D scanner. No significant differences in seed volume were observed when this parameter was measured with a 3D scanner and determined with the use of mathematical formulas based on the results of digital image analysis and micrometer measurements. The only differences were noted when the volume of yellow lupine seeds cv. Juno was measured in a 25 ml liquid pycnometer.

The aim of the study was to build numerical models of cucumbers cv. Śremski with the use of a 3D scanner and to analyze selected geometric parameters of cucumber fruits based on the developed models. The basic dimensions of cucumber fruits–length, width and thickness—were measured with an electronic caliper with an accuracy of d = 0.01 mm, and the surface area and volume of fruits were determined by 3D scanning. Cucumber fruits were scanned with an accuracy of d = 0.13 mm. Six models approximating the shape of cucumber fruits were developed with the use of six geometric figures and their combinations to calculate the surface area and volume of the analyzed agricultural products were identified. The surface area and volume of cucumber fruits calculated by 3D scanning and mathematical formulas were compared. The surface area calculated with the model combining two truncated cones and two hemispheres with different diameters, joined base-to-base, was characterized by the smallest relative error of 3%. Fruit volume should be determined with the use of mathematical formulas derived for a model composed of an ellipsoid and a spheroid. The proposed geometric models can be used in research and design.