Toxicity of Tall Fescue to Rape and Birdsfoot Trefoil Seeds and Seedlings1

Abstract

Water extracts from roots and leaves of fescue (Festuca arundinacea elator Schreb.) reduced germination and growth of the roots of rape (Brassica nigra) and birdsfoot trefoil (Lotus corniculatus L.), but effects varied, depending upon how the extracts were prepared. Ethanol extracts of roots and leaves of fescue reduced growth of roots and tops of rape and birdsfoot trefoil seedlings grown in sand containing nutrient solution. Ethanol extract of root‐free soil in which fescue had been grown did not inhibit growth of rape or birdsfoot trefoil seedlings.Rape and fescue seeds germinated normally in sand with nutrient solution in which rescue was growing. Fescue growing in association with rape plants in nutrient solution or distilled water significantly reduced the growth of rape leaves. When half of the rape and rescue root systems were independently supplied with nutrient solution, and half of their root systems were grown together in distilled “water, rescue inhibited the growth of rape roots in the distilled water. This ruled out competition for nutrients as an explanation of the inhibitory effects of rescue on the growth of rape.