紫茎泽兰对花生生长的影响及其经济阈值

为有效反映大田条件下紫茎泽兰对花生生长和产量的直接危害和经济危害允许水平,采用添加系列试验和模型拟合的方法研究不同紫茎泽兰密度下花生的生长和产量变化以及花生田间透光率和紫茎泽兰水肥积累量的变化。结果表明,花生在紫茎泽兰的竞争干扰下,花生荚果数、百仁重和果仁产量均随紫茎泽兰密度的增加而逐渐降低。花生荚果数和百仁重的降低可能是花生减产的直接原因。此外紫茎泽兰对田间透光率和对水肥的累积量的影响也可能是花生减产的重要原因。幂函数模型能较好地拟合紫茎泽兰密度（x）与花生产量损失率（y）间的关系（y=1.712x1.063,P〈0.0001）。花生田采用人工除草、草甘膦和氨氯吡啶酸对紫茎泽兰进行防除时,紫茎泽兰的经济危害允许水平分别为6.06%、0.57%、0.77%,经济阈值分别为3.28、0.36、0.46株.m-2。

Effects of Eupatorium adenophorum on growth of peanut and its economic threshold

To determine economic infestation level and economic threshold of Eupatorium adenophorum in peanut fields,additive series experiment and curve fit were adopted to study the changes of yield characteristics of peanut under different density of E.adenophorum in the fields.The results showed that with the interference of E.adenophorum,the peanut pods per plant,100-kernel weight and peanut kernel yield decreased gradually with the increasing weed density.The yield loss of peanut could be due to the decrease of peanut pods per plant and 100-kernel weight.Moreover,the interference of light penetration rate and accumulation of nutrient and water in E.adenophorum may also cause yield loss of peanut.The power regression model（y=1.712x1.063,P0.000 1） was relatively better in describing the relationship between E.adenophorum density（x） and yield loss（y） of peanut.The economic infestation levels for the E.adenophorum by manual weeding,glyphosate and picloram were 6.06%,0.57% and 0.77% respectively,and the economic thresholds were about 3.28,0.36,and 0.46 plant·m-2 respectively.