野黍对东北春大豆生长发育的影响及其经济阈值

为明确东北大豆田同期杂草野黍对大豆生长及产量的影响,探寻防治方法。大田条件下采用添加密度系列试验和拟合方程模型方法,研究同期杂草野黍对大豆主要农艺性状的影响及两者间的竞争关系,计算其经济阀值。结果表明:大豆株高、单株荚数和产量随野黍密度的增加呈降低趋势。对数函数模型拟合大豆产量损失率与野黍密度之间关系最好y=22.102Ln(x)-42.592(R2=0.977 2;F=171.338 4;P=0.000 2)。根据经济危害允许水平和对数函数模型,野黍人工防除的经济阈值为15.05株·m^-2,95%精异丙甲草胺乳油、24%烯草酮EC、10.8%高效氟吡甲禾灵EC化学防除野黍的经济阈值分别为8.19,7.59和7.67株·m^-2。野黍与大豆争夺田间光照和土壤水肥,导致大豆严重减产,采取化学防除野黍具有明显经济优势。

Effects of [Eriochloa villosa (Thunb.) Kunth] on the Growth and Development of Spring Soybean and Its Economic Threshold in Northeast China

Aimed to clarify the effect of [Eriochloa villosa(Thunb.) Kunth] on soybean growth and yield in Northeast soybean field in the same period and explore prevention method. The effects of main agronomic characteristics of soybean and the competition relationship between Eriochloa villosa and soybean was studied with the method of adding densities series test under field conditions and fitting equation model and the economic threshold was calculated. Results showed that increasing density of Eriochloa villosa significantly reduced plant height of soybean, soybean pod number per plant and yield under the interference and competition of Eriochloa villosa. Logarithmic functioned model y=22.102 Ln(x)-42.592(R2=0.977 2;F=171.338 4;P=0.000 2) could fit the best relationship between the density of Eriochloa villosa and the soybean yield loss. According to EIL and the Logarithmic function model, the economic threshold of Eriochloa villosa for manual weeding was 15.05 plant·m^-2, and the economic threshold for chemical weeding of 95% s-metolachlor EC, 24% enoxanone EC or 10.8% haloxyfop-P-methyl EC was 8.19, 7.59 and 7.67 plant·m^-2, respectively. Eriochloa villosa competes with soybean for light, water and nutrition of soil in the field, resulting in the yield reduction. Chemical herbicides control for Eriochloa villosa has obvious economic advantage.