Stalk lodging (breaking of agricultural plant stalks prior to harvest) is a multi-billion dollar a year problem. Stalk lodging occurs when bending moments induced by a combination of external loading (e.g. wind) and self-loading (e.g. the plant’s own weight) exceed the stalk bending strength of plant stems. Previous studies have investigated external loading and self-loading of plants as separate and independent phenomena. However, these two types of loading are highly interconnected and mutually dependent. The purpose of this paper is twofold: (1) to investigate the combined effect of external loads and plant weight on the flexural response of plant stems, and (2) to provide a generalized framework for accounting for self-weight during mechanical phenotyping experiments used to predict stalk lodging resistance. A mathematical methodology for properly accounting for the interconnected relationship between self-loading and external loading of plants stems is presented. The method was compared to numerous finite element models of plants stems and found to be highly accurate. The resulting interconnected set of equations from the derivation were used to produce user-friendly applications by presenting (1) simplified self-loading correction factors for common loading configurations of plants, and (2) a generalized Microsoft Excel framework that calculates the influence of self-loading on crop stems. Results indicate that ignoring the effects of self-loading when calculating stalk flexural stiffness is appropriate for large and stiff plants such as maize, bamboo, and sorghum. However, significant errors result when ignoring the effects of self-loading in smaller plants with larger relative grain sizes, such as rice (8% error) and wheat (16% error). Properly accounting for self-weight can be critical to determining the structural response of plant stems. Equations and tools provided herein enable researchers to properly account for the plant’s weight during mechanical phenotyping experiments used to determine stalk lodging resistance.

中文翻译：

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植物重量对茎秆抗倒性估计的影响

茎倒伏（在收获前破坏农业植物茎）是一个每年数十亿美元的问题。当外部负载（例如风）和自负载（例如植物自身重量）的组合引起的弯矩超过植物茎的茎弯曲强度时，就会发生茎倒伏。以前的研究已经将植物的外部加载和自加载作为单独和独立的现象进行了调查。然而，这两种类型的负载是高度相互关联和相互依赖的。本文的目的是双重的：（1）研究外部载荷和植物重量对植物茎的弯曲响应的综合影响，以及（2）在使用的机械表型实验中为解释自重提供一个通用框架来预测茎的抗倒伏性。提出了一种数学方法，用于正确解释植物茎的自负荷和外部负荷之间的相互关系。该方法与许多植物茎的有限元模型进行了比较，发现它非常准确。从推导中得到的相互关联的方程组被用于生成用户友好的应用程序，方法是提供 (1) 用于植物常见负载配置的简化自负载校正因子，以及 (2) 计算自身影响的通用 Microsoft Excel 框架-装载在作物茎上。结果表明，在计算茎秆弯曲刚度时忽略自加载的影响适用于玉米、竹子和高粱等大而坚硬的植物。然而，当忽略具有较大相对粒度的较小植物（例如水稻（8% 错误）和小麦（16% 错误））的自负荷效应时，会导致显着错误。正确计算自重对于确定植物茎的结构响应至关重要。本文提供的方程式和工具使研究人员能够在用于确定茎抗倒伏性的机械表型实验期间正确考虑植物的重量。