Allelopathic effects of white clover 1. Germination and chemical bioassay

摘要

Seed of 10 pasture species, germinated in the presence of an aqueous extract of freeze-dried white clover shoot material, showed inhibition of germination, and seedling abnormalities. A rate equivalent to 800 kg/ha of white clover dry matter (DM) almost totally inhibited the germination of white clover, alsike clover, cocksfoot, and perennial ryegrass seed. The addition of PVPP was able to remove up to 75 of observed inhibition. White clover plants grown in contrasting high country environments seldom produced levels of allelochemicals different to lowland white clover although summer-dry environments tended to promote allelochemical production. A chromatographic investigation implicated phenolics as the active allelochemicals.