Abstract: Main weeds species under intensified rice system were Rotala indica,Lindernia procumbens,Cyperus difformis and Leptochloa chinensis,of which Cyperus difformis and Leptochloa chinensis had stronger competition with rice plant.Compared with Japanic hybrid rice E52,Liangyoupeijiu can control weed growth greatly due to their stronger competitive ability.With the increase of row spacing,the control ability of rice over weeds decreased under the same planting density.When E52 was sparsely planted,there was no difference of control over weeds among different row spacing.Weed control method was discussed under intensified rice system.

Key words: Brontispa longissima, Experimental population, Temperature, Life table, Population parameter