High temperature (HT) and drought (D) have detrimental effects on growth and phenology that result in reductions of the yields of agricultural crops. Nevertheless, homeostatic ranges of tolerance exist. Recent analysis of survey data and simulations suggest US wheat (Triticum aestivum L.) yields remain relatively stable under irrigation in the range of 35°– 40°C. Applying analogue statistical procedures on experimental data and simulations from the Hot Serial Cereal Experiment (HSC) we demonstrate that failed incorporation of the corresponding phenological acceleration due to HT and a low interannual temperature variability lead to this result. Here, we incorporate the phenological effect into the used binned temperature exposure yield model by rescaling (normalizing) the absolute seasonal temperature counts to a maximum season length. The application to observed and simulated HSC data with a wide temperature range reveals that the suggested upper homeostatic response limit of US wheat yields to HT requires a down–revision. HT stress can be reduced by transpirational cooling. However, the effect is currently not sufficient to expand the homeostatic range of irrigated wheat markedly beyond 25°C taking our analysis of the HSC experiment.

高温 (HT) 和干旱 (D) 对生长和物候有不利影响，导致农作物产量下降。然而，存在耐受的稳态范围。最近对调查数据和模拟的分析表明，美国小麦（Triticum aestivumL.) 在 35°– 40°C 范围内的灌溉条件下，产量保持相对稳定。对来自热序列谷物实验 (HSC) 的实验数据和模拟应用模拟统计程序，我们证明由于 HT 和低年际温度变化导致相应物候加速的结合失败导致了这一结果。在这里，我们通过将绝对季节性温度计数重新缩放（标准化）到最大季节长度，将物候效应纳入使用的分箱温度暴露产量模型中。对具有较宽温度范围的观察和模拟 HSC 数据的应用表明，美国小麦产量对 HT 的建议稳态响应上限需要向下修正。蒸腾冷却可以降低 HT 压力。然而，