Effects of Stachytarpheta jamaicensis on Seed Germination and Seedling Growth in Six Plant Species

In order to explore the effect of S.jamaicensis on native crops,Effects of aqueous flower extract from S.jamaicensis on seed germination and seedling growth in six economic crops were studied by filter paper method.The results showed that all the water extract inhibited the seed germination rate and germination index of these six plant species.And this inhibition became strong as the concentration of extractions increased.The aqueous flower extracts exhibited allelopathic promotion at low concentration and allelopathic inhibition at high concentration on the seedling root length.And had both accelerating and inhibiting effects on seedling height,but suppressed chlorophyl a content and CAT activity as a whole.According to the synthesis allelopathic effect value,all the water extracts had slight promotion effect on Brassica chinensis,but had inhibition effect on the other five crops with the order of Brassica campestrisLactuca sativaAmaranthus tricolorIpomoea aquaticaCucumis sativus in the mass.