Separating germinable and non-germinable seeds of eastern white pine (Pinus strobus L.) and white spruce (Picea glauca [Moench]Voss) by the IDS technique

Estimates of the percentage of filled-dead seeds contained in two seedlots of eastern white pine and white spruce were obtained from cutting tests following the standard germination test for each species. After incubation samples of seeds from these seedlots were partially desiccated in a drying cabinet until the percentage of floating seeds, out of 100 seeds placed in water, was equal to the estimated percentage of filled-dead seeds. Then the seeds in each seedlot were separated in a water column.This separation resulted in a significant improvement in germination percentage from 50.2% to 86.0% when the control and bottom fractions were compared for the white spruce seedlot with the poorest germinability and from 46.2% to 69.0% for the white pine seedlot with poorest germinability. Mean germination time for the above seedlots was not significantly reduced for either species. There was no significant difference in germinability among the dried and the fresh subsamples of the bottom fractions for any seedl...