Variability in and correlations among selected physical properties of European larch (Larix decidua Mill.) seeds

Selected physical attributes of European larch seeds harvested from 2 seed plantations and 2 commercial seed stands in north-eastern Poland were determined. The physical properties of seeds were measured, and the results were used to calculate indicators of seed weight and the frictional and geometric properties of seeds. Physical attributes and indicators were compared by Student’s t-test for independent samples, analysis of variance, correlation analysis and linear regression analysis. The average values of physical properties and indicators were determined at: critical transport velocity - from 5.93 to 6.13 m • s-1, thickness - from 1.25 to 1.43 mm, width - from 2.29 to 2.71 mm, length - from 3.71 to 4.57 mm, angle of sliding friction - from 27.85 to 31.98o, weight - from 4.03 to 6.14 mg, coefficient of sliding friction - from 0.54 to 0.63, arithmetic mean diameter - from 2.42 to 2.90 mm, geometric mean diameter - from 2.20 to 2.60 mm, aspect ratio - from 59.60 to 62.38%, sphericity index - from 57.27 to 59.40%, specific weight - from 1.81 to 2.33 g • m-1, volume - from 4.60 to 7.59 mm3 and density - from 0.82 to 0.91 g • cm-3. The material harvested in seed plantations differed from seeds from commercial seed stands in all parameters, excluding critical transport velocity. Seed weight was most correlated with the remaining parameters. The highest value of the correlation coefficient and the equation with the highest value of the coefficient of determination were reported for the dependence between seed weight and seed length. Seed weight was also relatively highly correlated with seed width, therefore, the use of mesh screens with round openings and/or cylindrical grain graders is recommended in seed sorting processes.