APPLYING THE IDS METHOD TO REMOVE EMPTY SEEDS IN PLATANUS X ACERIFOLIA

The IDS (incubation, drying, separation) technique, designed to upgrad e germinability of conifer seeds, was tested on Platanus xacerifolia ( Ait.) Willd. seeds in an attempt to sort empty from full seeds. Incuba ted seeds were dried to seven levels of moisture content followed by s eparation in petroleum ether. After 24 h of drying (13.6% moisture con tent) the germination percentage in the bottom (sunken) fraction was r aised to 86% compared with 48% of untreated seeds. Mean germination ti me decreased from 3.5 to 2.4 days. IDS-treated seeds were then dried t o 7% moisture content without detrimental effect either on germinabili ty or on speed of germination, thus giving the possibility of storing upgraded seeds. Specific gravity separation in petroleum ether of untr eated seeds was also tested; in the bottom fraction, the germination p ercentage was 60.5% compared with 48% for untreated seeds.