Abstract: In order to evaluate the  lodging resistance of rapeseed stems with biomechanical methods, and provide guidance for anti-lodging cultivation of rape，Huaza 62 and Jinyouza 158 were used to investigate elastic modulus (EM), bending strength (BS), and shear strength (SS) and their lodging resistance under different cultivation factors, the influence of cultivation factors on the mechanical properties of rapeseed stem and its correlation with lodging resistance were analyzed. The results showed as follows: lodging resistance of rapeseed was negatively correlated with EM, BS, and SS; with the delay of sowing date, EM, BS and SS were reduced by 15.31%, 29.16% and 13.88%, respectively, while stem lodging resistant index (CLRI) was increased by 32.18%；EM, BS and SS were increased firstly and then decreased with the increase of sowing density, while CLRI was decreased first and then increased. With the nitrogen fertilizer rate increased, EM, BS and SS were gradually decline, while CLRI rising. EM, BS and SS of 360 kg·hm^-2 were reduced by 39.43%, 19.40% and 16.63%, respectively, compared to treatment of 120 kg·hm^-2, CLRI was increased by 16.36%. In conclusion, the mechanical strength characteristics and the lodging resistance of rapeseed could be enhanced with the delay of sowing date, the slight increase of sowing density and the decrease of nitrogen fertilizer rate. This research  provided a theoretical basis for rapeseed cultivation.

摘要： 为了应用生物力学特性指标对茎秆抗倒性进行评价，进而指导油菜抗倒栽培，以华杂62和金油杂158为试验材料，基于不同栽培因素下油菜茎秆的弹性模量、弯曲强度、剪切强度及抗倒性，分析了栽培因素对油菜茎秆力学特性指标的影响及其与抗倒性的相关性。结果表明：油菜抗倒性与茎秆的弹性模量、弯曲强度、剪切强度呈显著负相关；随着播期推迟，油菜茎秆的弹性模量、弯曲强度及剪切强度分别减小15.31%、29.16%和13.88%，倒伏指数增大32.18%；随着播种密度增大，油菜茎秆的弹性模量、弯曲强度及剪切强度均呈先增大后减小趋势，而倒伏指数先减小后增大；随着施氮量增加，油菜茎秆的弹性模量、弯曲强度及剪切强度均逐渐减小，而倒伏指数逐渐增大，与施氮量120 kg·hm^-2处理相比，在施氮量为360 kg·hm^-2下，油菜茎秆的弹性模量、弯曲强度及剪切强度分别减小39.43%、19.40%和16.63%，倒伏指数增大16.36%。因此，播期提前、适当增加播种密度、控制氮肥投入，有助于提高油菜茎秆的力学特性强度，从而增强油菜的抗倒伏能力。研究结果可为油菜抗倒栽培调控提供理论依据。

关键词: 油菜, 生物力学, 倒伏, 栽培因素