Sorghum production system in the semi-arid region of Africa is characterized by low yields which are generally attributed to high rainfall variability, poor soil fertility, and biotic factors. Production constraints must be well understood and quantified to design effective sorghum-system improvements. This study uses the state-of-the-art in silico methods and focuses on characterizing the sorghum production regions in Mali for drought occurrence and its effects on sorghum productivity. For this purpose, we adapted the APSIM-sorghum module to reproduce two cultivated photoperiod-sensitive sorghum types across a latitude of major sorghum production regions in Western Africa. We used the simulation outputs to characterize drought stress scenarios. We identified three main drought scenarios: (i) no-stress; (ii) early pre-flowering drought stress; and (iii) drought stress onset around flowering. The frequency of drought stress scenarios experienced by the two sorghum types across rainfall zones and soil types differed. As expected, the early pre-flowering and flowering drought stress occurred more frequently in isohyets < 600 mm, for the photoperiod-sensitive, late-flowering sorghum type. In isohyets above 600 mm, the frequency of drought stress was very low for both cultivars. We quantified the consequences of these drought scenarios on grain and biomass productivity. The yields of the highly-photoperiod-sensitive sorghum type were quite stable across the higher rainfall zones > 600 mm, but was affected by the drought stress in the lower rainfall zones < 600 mm. Comparatively, the less photoperiod-sensitive cultivar had notable yield gain in the driest regions < 600 mm. The results suggest that, at least for the tested crop types, drought stress might not be the major constraint to sorghum production in isohyets > 600 mm. The findings from this study provide the entry point for further quantitative testing of the Genotype × Environment × Management options required to optimize sorghum production in Mali.

非洲半干旱地区高粱生产系统的特点是产量低，这通常归因于降雨量变化大、土壤肥力差和生物因素。必须充分理解和量化生产限制，才能设计有效的高粱系统改进。本研究采用最先进的计算机方法，重点描述马里高粱产区的干旱发生情况及其对高粱生产力的影响。为此，我们采用了 APSIM-sorghum 模块，在西非主要高粱产区的纬度上复制了两种栽培的光周期敏感高粱类型。我们使用模拟输出来描述干旱胁迫情景。我们确定了三种主要的干旱情景：(i) 无压力； (ii) 早期开花前干旱胁迫； (iii) 干旱胁迫在开花前后开始。两种高粱类型在不同降雨区和土壤类型中经历的干旱胁迫情景的频率不同。正如预期的那样，对于光周期敏感的晚花高粱类型来说，早花前期和开花干旱胁迫在等高度 < 600 mm 的高粱中更频繁地发生。在 600 毫米以上的等雨高度中，两个品种的干旱胁迫频率都非常低。我们量化了这些干旱情景对粮食和生物量生产力的影响。在> 600毫米的较高降雨量区域，光周期高度敏感的高粱类型的产量相当稳定，但在< 600毫米的较低降雨量区域受到干旱胁迫的影响。相比之下，光周期敏感性较低的品种在<600毫米的最干旱地区产量显着增加。 结果表明，至少对于测试的作物类型来说，干旱胁迫可能不是等高线 > 600 毫米高粱生产的主要限制因素。这项研究的结果为进一步定量测试优化马里高粱生产所需的基因型×环境×管理选项提供了切入点。