The coffee research community has maintained a long ongoing debate regarding the implications of shade trees in coffee production. Historically, there has been contrasting results and opinions on this matter, thus recommendations for the use of shade (namely in coffee agroforestry systems) are often deemed controversial, particularly due to potential yield declines and farmers’ income. This study is one of the first demonstrating how several Coffea arabica cultivars respond differently to shade with respect to yield. By standardising more than 200 coffee yield data from various in-field trials, we assembled the so-called “Ristretto” data pool, a one of a kind, open-source dataset, consolidating decades of coffee yield data under shaded systems. With this standardised dataset, our meta-analysis demonstrated significant genotypic heterogeneity in response to shade, showing neutral, inverted U-shaped and decreasing trends between yield and shade cover amongst 18 different cultivars. These findings encourage the examination of C. arabica at the cultivar level when assessing suitability for agroforestry systems. Comparison of productivity is also encouraged across a range of low to moderate shade levels (10–40%), in order to help elucidate potential unknown optimal shade levels for coffee production.

咖啡研究界一直在就遮荫树对咖啡生产的影响进行长期辩论。从历史上看，在这个问题上存在不同的结果和意见，因此使用遮荫的建议（即在咖啡农林业系统中）通常被认为是有争议的，特别是由于潜在的产量下降和农民收入。这项研究是首次展示几种阿拉比卡咖啡就产量而言，品种对遮荫的反应不同。通过对来自各种现场试验的 200 多个咖啡产量数据进行标准化，我们组装了所谓的“Ristretto”数据池，这是一个独一无二的开源数据集，在阴影系统下整合了数十年的咖啡产量数据。有了这个标准化的数据集，我们的荟萃分析证明了对遮荫的显着基因型异质性，在 18 个不同品种的产量和遮荫覆盖之间显示出中性、倒 U 形和下降趋势。这些发现鼓励对C. arabica的检查在评估农林业系统的适用性时，在品种层面。还鼓励在低至中等遮光度（10-40%）范围内比较生产力，以帮助阐明咖啡生产的潜在未知最佳遮光度。