Abstract:

【Objective】 Field experiments were conducted to screen out rice varieties with higher suppressive ability against weeds, and to explore the ecological weed management technics based on ecological relationship of rice and weeds. 【Method】Biological community of rice and weeds including barnyardgrass [Echinochloa crusgalli(L.) Beauv], sedge and broad leaved weeds were established, and the suppressive effect of different rice cultivars on weeds were analyzed quantitatively. 【Result】Liangyouhua 6 demonstrated suppressive effect on barnyardgrass, sedge and broad leaved weeds soon after rice transplanting. The suppressive effects of most tested rice varieties on barnyardgrass germination and dry weight were 79.14%-88.84% and 84.44%-90.23%, respectively, while the effects on broad leaved weeds were quite different at the time of 50d after rice transplanting. The suppressive effects on the weed germination, development and biomass accumulation mediated by Liangyouhua 6, Liangyou 932, and PI312777 were excellent compared with other rice cultivars, the effects were above 80% and 85%-90%, respectively. The same tendency was found in the suppressive effect on dry weight of total weeds and those on dry weight of barnyardgrass among the tested rice cultivars. 【Conclusion】 It is feasible and significant to screen out rice varieties with higher suppressive ability against weeds. Planting of the rice cultivars with suppressive traits such as strong tilling ability, fast growing and optimal population performance could improve ecological weed management in paddy field.

Key words: rice varieties, suppressive effect, weed, evaluation