Allelopathic effects on germination percentage in some leguminous and tall fescue (Festuca arundinacea Schreb.)

The study was performed to examine interactions in seed germination in a mixture of leguminous crops and grasses. In red clover (Trifolium pratense), lucerne (Medicago sativa), birdsfoot trefoil (Lotus corniculatus) seeds grown in association with tall fescue (Festuca arundinacea) germination percentage was evaluated on days one to seven. The experiments involved two treatments of seed geometry and two treatments of seed density. The species grown in monoculture served as control. The effect of released allelopathic substances was most marked in a combination of birdsfoot trefoil and grass resulting in reduced germination percentage of both seeds at the start of culture. The allelopathic effects of substances released from seeds acted inhibitory or stimulating in the first days of germination. To the end of evaluation there were no significant differences in germination percentage among seed mixtures and the controls. Sowing density and seed geometry had no unambiguous and significant effect on germination percentage. Of the leguminous crops studied birdsfoot trefoil exhibited the highest allelopathic potential and also tall fescue was considered as a grass with a high allelopathic potential. The results are in good agreement with the concentrations of phenolic substances given in a follow-up to this study.