Germination and Seedling Growth of 48 Plant Species as Affected by a Leachate from Seeds of Coronilla Varia L.

The study investigated the effects of leachate from seeds of crownvetch (Coronilla varia L.) on the germination and seedling growth of 48 plant species. While germination was not inhibited, the leachate, particularly when freeze-dried and diluted up to 1:2,000, significantly reduced shoot and root growth and nearly eliminated root hair development. Root tips became necrotic, and roots thickened, with some exhibiting negative geotropism. Even at a dilution of 1:10,000, some seedlings were adversely affected. The osmotic pressure of the leachate was too low to explain these effects, suggesting that low molecular weight phenols and polyphenols in the crownvetch leachate were responsible. The crownvetch leachate was more phytotoxic than leachates from sweetclover and aged red clover seeds.