杂草稻落粒粳(Oryzasativa)发生在我国辽宁丹东.落粒粳植株明显高于当地大多数栽培品种,颖果呈中长型,成熟后容易掉粒;果壳稻草色或黄间黑灰色,小穗无芒或有芒,芒长4～12cm ;颖果千粒重2 . 35 g ,种皮桔红色.落粒粳种子在13～38℃条件下的发芽率均大于88% ,水层2 . 5～10cm处理,落粒粳植株干重减少5. 0 %～6 .9% .在幼苗期,落粒粳对无芒稗的各项影响因子均明显大于化感潜力品种I kung pao ,表明落粒粳无化感作用.落粒粳可以忍耐0. 5 %的盐碱. Oryzasativa occurs in Dandong, Liaoning Province of China. The plants of falling-off japonica are obviously higher than most cultivars in the area, and the caryopsis is medium-long and easy to fall out after ripening. The color of husk straw or yellow-black , Spikelets or mango, mango 4 ~ 12cm; caryopsis weight 2. 35g, seed coat orange-red.Japanese japonica seeds germinated at 13 ~ 38 ℃ germination rate of more than 88%, water layer 2 .5 to 10 cm treatment, the dry weight of japonica plantlets dropped by 5.0% -6.9% .In the seedling stage, the impact factors of seedless japonica to barnyardgrass were significantly greater than the allelopathic potential varieties I kung pao, 5% 的 盐碱. That drop grain japonica no allelopathy role.