Study on Allelopathy in Rice with Barnyardgrassin Northern China

Thirty-seven rice varieties from northern China were identified for allelopathy to barnyardgrass(Echinochloa crusgalli) by using the relay seeding technique with slight modification for seeking rice germplas with allelopathy.Results showed that the rice variety had great difference in plant height,root growth,and dry weight to barnyardgrass.1046,Tiyou35,TA/C4115,Shennong315,TA/C418 had strong allelophathic inhibitition effect;265-11,Gaoyou8 had no allelophathic effect to barnyardgrass;265,265-2 had promoting effect.Many rice varieties had higher inhibitory rate on the root growth of barnyardgrass than plant growth with higher inhibitory rate on root dry weigh than the plant dry weight.