紫茎泽兰对茄子产量的影响及其经济阈值

为了有效反映大田条件下,紫茎泽兰对茄科植物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观察了不同紫茎泽兰密度下茄子的株高和产量变化,以及茄子田间透光率和紫茎泽兰水肥积累量的变化。结果表明,当紫茎泽兰密度为1～2株/m2时,对茄子株高、结果数和产量无影响,当紫茎泽兰密度增加到5株/m2以上时,茄子株高、结果数和产量显著降低。紫茎泽兰的株高、对田间透光率的干扰程度和水肥积累量是茄子减产的重要原因。双曲线模型（1/y=-0.0108＋0.2083/x）可以较好地拟合紫茎泽兰密度与茄子产量损失间的关系。茄子田间紫茎泽兰的经济危害允许水平为0.192%～1.282%,经济阈值为0.03～0.26株/m2。

Effects of Eupatorium adenophorum on the eggplant yield and its economic thresholds

A field experiment was carried out to study the direct damage of Eupatorium adenophorum Spreng on eggplant yield and its economic infestation levels. Additive series experiment and curve fits were adopted to study the change of eggplant height and yield characteristics under different densities of E.adenophorum and the competitive mechanisms of light, nutrients and water between eggplant and the weed. The results showed that the eggplant height, fruit number and its yield were not affected when the densities of E.adenophorum ranged from 1 to 2 plants per m², whereas, the eggplant height, fruit number and its yield decreased significantly when the density of the weed was more than 5 plants per m². The main cause of the eggplant yield loss may be due to the plant height of E.adenophorum, the interference to the rate of light penetration and the accumulation of water and nutrition in E.adenophorum. The hyperbola model (1/y=-0.0108+0.2083/x) could well fit the relation between the eggplant yield loss (y) and the weed density (x). The economic infestation level for E.adenophorum in eggplant field was between the range of 0.192% and 1.282%. The economic threshold was 0.03-0.26 plants per m².