Determination of Wood Specific Gravity in Standing White Spruce Using a Pilodyn Tester

A simple spring-load pin-ejecting instrument, the "Pilodyn", was used to assess wood specific gravity of standing white spruce (Picea glauca (Moench) Voss) trees. Pin penetrations in both debarked and unpeeled trees were compared with outerwood specific gravity determined from actual core samples taken near the Pilodyn test spots. High degrees of correlation were found for Pilodyn penetration measurements and the outerwood specific gravities. The Pilodyn tester can be used in tree specific gravity estimation as part of a selection program for tree improvement.