One of the main challenges of using low plant densities in restrictive and variable environments is to maximize the use of resources in better-than-expected years. In this context, tillering could be an alternative to increase reproductive and vegetative plasticity. The objectives of this study were to (a) characterize the correlation between environmental conditions, tiller traits, crop grain yield, and grain yield advantages due to tillers; (b) determine the grain yield response to tillering (i.e., grain yield difference between tillered and nontillered crops) for a wide range of environments; and (c) to evaluate the effect of tiller presence on grain yield of the main shoot, considering its effect on the apical and subapical ears. Tillered and nontillered crops were evaluated under rainfed conditions during two seasons (2018–2019 and 2019–2020). These experiments were carried out at 11 sites in the southern Argentinean Pampas, varying sowing date (22 Oct. to 5 Dec.), plant density (2–3 plants m⁻²), genotype (AX7784 and AX7761), and soil depth. Grain yield (3.2–11.9 Mg ha⁻¹) was correlated with tillers productivity, mainly explained by postflowering precipitations. The contribution of tillers to grain yield was more proportional than their consequent yield depression at the main shoot. Tillers either increased (3 sites) or maintained (8 sites) grain yield, and their contribution increased as the environment improved without any detrimental effect in the most restrictive environments. Tillering has the potential for increasing resource (radiation, water, nitrogen) use efficiency under low plant density strategies adopted for restrictive environments.

中文翻译：

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低种植密度下分蘖对玉米产量稳定性的贡献

在限制性和多变的环境中使用低植物密度的主要挑战之一是在好于预期的年份最大限度地利用资源。在这种情况下，分蘖可能是增加生殖和营养可塑性的替代方法。本研究的目的是 (a) 描述环境条件、分蘖性状、作物粮食产量和分蘖导致的粮食产量优势之间的相关性；(b) 确定大范围环境下谷物产量对分蘖的反应（即分蘖和非分蘖作物之间的谷物产量差异）；(c) 评估分蘖存在对主枝谷物产量的影响，考虑其对顶穗和亚顶穗的影响。在两个季节（2018-2019 年和 2019-2020 年）的雨养条件下对分蘖和非分蘖作物进行了评估。⁻²）、基因型（AX7784 和 AX7761）和土壤深度。谷物产量 (3.2–11.9 Mg ha ^-1 ) 与分蘖生产力相关，主要通过花后降水来解释。分蘖对谷物产量的贡献比它们在主枝上造成的产量下降更成比例。分蘖增加（3 个地点）或维持（8 个地点）粮食产量，并且随着环境的改善，他们的贡献增加，而在最受限制的环境中没有任何不利影响。在为限制性环境采用的低植物密度策略下，分蘖有可能提高资源（辐射、水、氮）的利用效率。