Analysis of correlations between selected physical properties and color of scots pine (Pinus sylvestris L.) seeds

Selected physical properties of Scots pine seeds harvested from five plantations in north-eastern Poland were determined. Seed color was determined in a sensory analysis, and seeds were classified into one of four color groups: black, brown, gray or other. The results of measurements were used to calculate indicators of seed weight and seeds’ frictional and geometric properties. Physical attributes and indicators were compared by one-way analysis of variance, correlation analysis and linear regression analysis. The average values of physical properties and indicators characterizing seeds from different color groups were determined at: critical transport velocity - from 7.0 to 7.1 m • s-1, thickness - from 1.48 to 1.50 mm, width - from 2.51 to 2.54 mm, length - from 4.32 to 4.46 mm, angle of sliding friction - from 29.1 to 29.8o, weight - from 6.4 to 6.7 mg, coefficient of sliding friction - from 0.56 to 0.58, arithmetic mean diameter - from 2.77 to 2.82 mm, geometric mean diameter - from 2.52 to 2.55 mm, aspect ratio - from 56.91 to 58.64%, sphericity index - from 57.44 to 58.69%, specific weight - from 2.51 to 2.60 g • m-1, volume - from 7.90 to 8.24 mm3 and density - from 0.80 to 0.82 g • cm-3. Selected color groups differed only in length, aspect ratio and sphericity index. Seed weight was most highly correlated with the remaining attributes, and the highest value of the correlation coefficient and the equation with the highest value of the coefficient of determination were reported for the correlation between seed weight and thickness.