The effect of the age of Scots pine (Pinus sylvestris L.) stands on the physical properties of seeds and the operating parameters of cleaning machines

Critical transport velocity, the thickness, width, length, the angle of sliding friction and weight of Scots pine seeds harvested from conservation seed stands were measured. Correlations were determined between the age of parent stands (124 to 180 years old) and the above parameters of Scots pine seeds. Significant correlations were found between the age of parents stands and the weight, dimensions and the angle of sliding friction of seeds. Such a correlation was not observed for critical transport velocity. The noted correlations were presented as first-order equations which show that among the studied seed properties, average seed weight changed to the highest degree – it decreased by ca. 15% as Scots pine trees grew older.