Effects of water extracts of Flaveria bidentis on the seed germination and seedling growth of three plants

To further explore the mechanism behind the allelopathic effects of Flaveria bidentis, we investigated the allelopathic effects of water extracts from Flaveria bidentis leaves on three plants, Shanghai green, barnyard grass and wheat. The results showed that the water extracts inhibited the germination potential, germination rate, seedling height, root length, chlorophyll content, fresh weight and dry weight of the three plants, and increasing the extract concentration further increased the inhibitory effect. The allelopathic effects of the water extracts from Flaveria bidentis leaves on the three receptor plants differed in strength from strong to weak as follows: Shanghai green > barnyard grass > wheat. Thus, wheat had strong resistance to the allelopathic effects of Flaveria bidentis and could be planted in area where Flaveria bidentis occurs. The effect of the water extract from Flaveria bidentis leaves on the seed germination and seedling growth of barnyard grass was obvious; thus, this extract could be used for the biological control of barnyard grass.