Effects of aqueous extracts from the stems and leaves of Trifolium pratense cv. Minshan ongermination and seedling growth of three crops

The allelopathy effects of aqueous extract from Trifolium pratense cv. Minshan on three receptor plants were investigated through bioassay of seed germination and seedling growth. Red clover stems and leaves were soaked in distilled water for 48 hours. Then distilled water was added to create four grades of concentrations (0.05, 0.10, 0.15 and 0.20 gmL-1). The results showed that different concentrations of aqueous extract from the stem and leaf of red clover had different allelopathy effects on germination and seedling development of the three receptor plants. There was no significant difference on germination rate for all three receptor plants among the four concentrations of aqueous extract. However, soaking solution (less than 0.20 gmL-1) did significantly inhibit the radicle and seedling growth of pakchoi (P0.05). Soaking solution at 0.2 gmL-1 concentration significantly reduced the radicle growth of oat, Dahurian wildrye, and pakchoi by 23.76%, 35.73% and 62.50% (P0.05), respectively. Soaking solution at 0.05 gmL-1, however, significantly promoted the growth of Dahurian wildrye (P0.05). Among the three receptors, pakchoi was the most sensitive to the aqueous extract.