中文摘要：

分别对大豆田、棉田和果园里的火柴头群体进行调查研究,研究火柴头在田间的分布及其在大豆田中的竞争临界期。结果表明：火柴头生长繁殖迅速,生物量大,可以迅速扩展或占领生态位,从而对农作物的产量产生影响;火柴头危害后,可明显降低大豆的有效荚数及百粒重,使大豆产量减少;火柴头在大豆田危害的时间越长,大豆减产越严重,且不同的危害时期对大豆的产量影响不同,其中大豆花芽分化至豆荚形成是火柴头的竞争临界期,该时期火柴头对大豆危害最大。

英文摘要：

Commelina bengalensis L. is a common farmland weed, in order to explore its growth and distribution in soybean fields, cotton fields and fruit orchards, and its critical period of competition in soybean field, the growth of Commelina bengalensis L. in soybean fields, cotton fields and fruit orchards were studied. Our results showed that Commelina bengalensis L. grew and reproduced rapidly, and had large amount of biomass, so it could expand and occupy the ecological niche easily, and affect the production of crops. When the soybean was affected by Commelina bengalensis L. the number of effective pods and seeds weight were lower than the control. The longer the Commelina bengalensis L. growing in soybean fields, the lower would be soybean yield. The result showed that the critical period of competition between Commelina Bengalensis L. and soybean is the time from soybean flower bud differentiation to pod appeared, and also the period that was most harmful to the production of soybean.