【摘 要】
：
To identify the allelopathic effect of Flaveria bidentis (L.) Kuntze (F, bMenti) on other plants, the effects of different extracts from F. bidentis on the grow
【机 构】
：
College of Plant Protection, Agricultural University of Hebei, Baoding 071001, China
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To identify the allelopathic effect of Flaveria bidentis (L.) Kuntze (F, bMenti) on other plants, the effects of different extracts from F. bidentis on the growth of sev-eral plants were studied by bioassay. Results showed that the water extracts inhibited the growth of co (Zea mays L.), wheat (Triticum aestivum L.), cotton (Gassypium Hirsutum L.), soybean (Glycine hispida L.), peanut (Arachi shypogaea L.), rice (Oryza sativa L.), crabgrass (Digitaria sanguinalis L.) and rigweed (Amaranthus retroflexus L.), with the most reactive indexes found in root and stem of cotton at -0.85 and -0.88, respectively, at a concentration growth of rice. In addition, the reactive indexes of the extracts of petroleum ether chloroform, ethyl acetate, acet and alcohol were higher than that of the water extracts, and that of the acet extracts was the highest. The melting point of the refined acetone extract ranged from 192.5℃ to 193.5℃, and its maximum absorbing wavelength was 220 nm. This extract was found to be herbicide-active and played an inhibitory role in the growth of crabgrass and
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