Long-term selection in maize (Zea mays L.) favored single-stalked phenotypes limiting vegetative growth. However, reduced plant densities create conducive environments to the expression of vegetative branches called tillers. Tiller expression has motivated discussions about its yield effect in variable environments, but tiller research is lacking for modern corn genotypes. The objectives of this study were to (a) quantify the relative importance of management, environment, and interactions on the yield effect of tiller expression for two modern genotypes; (b) understand effects of observed tiller density, plant density, and their interaction on yield; and (c) identify key environmental determinants of yield response to tiller density in modern genotypes. In 10 environmentally diverse site-years across Kansas, tiller presence and removal were evaluated in two commercial corn hybrids (P0657AM and P0805AM) across three target plant density levels (25,000, 42,000, and 60,000 plants ha⁻¹). Yields were increased or unaffected by greater plant densities and tiller presence within site-years. Environments varied in yield responsiveness to tiller density, but fine-tuning plant density was needed to maximize yields. Sites with yields most responsive to tiller density were characterized by good soil properties and photothermal quotient values (e.g., soils with high organic matter and climates with greater solar radiation and cooler temperatures). Favorable growing conditions can be exploited by plasticity traits such as tillering in unpredictable environments with annually variable optimum plant densities while limiting potential yield loss and producer risk due to disproportionate plant density.

中文翻译：

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分蘖对玉米产量的影响：在不可预测的环境中探索性状可塑性潜力

玉米的长期选择（Zea maysL.) 有利于限制营养生长的单茎表型。然而，降低的植物密度为称为分蘖的营养分枝的表达创造了有利的环境。分蘖表达激发了关于其在可变环境中的产量影响的讨论，但缺乏现代玉米基因型的分蘖研究。本研究的目的是 (a) 量化管理、环境和相互作用对两种现代基因型分蘖表达产量影响的相对重要性；(b) 了解观察到的分蘖密度、植物密度及其相互作用对产量的影响；(c) 确定现代基因型中产量对分蘖密度响应的关键环境决定因素。在堪萨斯州的 10 个环境多样化站点年中，^-1 )。在现场年中，更高的植物密度和分蘖的存在增加或不影响产量。环境对分蘖密度的产量响应各不相同，但需要微调植物密度以最大限度地提高产量。产量对分蘖密度最敏感的地点的特征是良好的土壤特性和光热商值（例如，有机质含量高的土壤和太阳辐射较大且温度较低的气候）。有利的生长条件可以通过可塑性特征来利用，例如在不可预测的环境中分蘖，每年最佳植物密度都在变化，同时限制由于植物密度不成比例导致的潜在产量损失和生产者风险。