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期 刊 ：植物保护学报 2004年

关键词：菵草；油菜；竞争；防除阈值；

Keywords:Beckmannia syzigachne, rape, competition, economic control threshold,

摘 要 ：采用添加系列试验研究了菵草与移栽油菜间的竞争关系.结果表明,菵草与油菜竞争光能,田间光照强度随菵草密度的增加而降低.移栽油菜在菵草的竞争干扰下,单株分枝数、角果数、千粒重及产量均随菵草密度增加而逐渐降低,油菜减产主要与菵草密度增大引起单株角果数减少有关.油菜产量损失与菵草密度之间的关系可用y = -0.0003x2 0.2269x 4.7638的数学模型来模拟,油菜田菵草的经济危害允许水平为3.24%,其防除阈值为8株/m2.

Abstract:Beckmannia syzigachne is a noxious weed in rape fields.The competition between Beckmannia syzigachne and transplanted rape was studied with additive series experiment.The results showed that the light intensity of the rape fields decreased with the increa

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