The global population is projected to be enormous by the mid-21st century, whereas, most essential crops being sustained by the rain-fed agriculture are threatened by climate change. Therefore, the study investigated the projected near-future effect of rainfall variability on rot incidence and yam production in humid tropical Nigeria. Production data from the Food and Agriculture Organization and the Nigeria National Bureau of Statistics showed the significant increasing trend in the annual yam output. The field survey conducted in 2018 showed that the maximum percentage of rot incidence occurred in July. Climate Research Unit observational rainfall data from 1979 to 2018 showed the nonsignificant trend in the interannual rainfall variability; however, it showed low variability and a significant decreasing trend in the July rainfall. A pathogenicity test on yam samples confirmed rot by fungi, bacteria and nematodes as virulent pathogens, whereas, the nutritional qualities of the rotted yams were indicated. Monthly rainfall and rot incidence showed positive correlation (r = 0.84, significant at 99% from t-test). The positive characteristic impact values indicated that increase (decrease) in the monthly rainfall corresponds to increase (decrease) in the magnitude of monthly percentage rot incidence. Thus, the significantly decreasing rainfall reduced the quantity of rot incidence and consequently increased the annual yam production for the period. Selected CoOrdinated Regional Downscaling EXperiment-Africa models and the ensemble mean showed a good measure of agreement with observational rainfall in the historical experiments. The efficiencies of the bias-corrected outputs in the representative concentration pathway (RCP) 4.5 and 8.5 indicated improved ‘reasonable’ performances. Bias-corrected projections of the July rainfall showed an increasing trend in both the RCPs, which indicate a potential increase in rot incidence and the consequent decline in annual yam production. The findings are imperative in sustaining the global food supply.

中文翻译：

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气候变化对潮湿热带地区山药腐烂发病率的近期影响：CORDEX-Africa 情景中的预测

预计到 21 世纪中叶，全球人口将非常庞大，而由雨养农业维持的大多数重要作物都受到气候变化的威胁。因此，该研究调查了降雨变化对潮湿热带尼日利亚腐烂发病率和山药产量的预计近期影响。粮食及农业组织和尼日利亚国家统计局的生产数据显示，山药年产量呈显着增长趋势。2018 年进行的实地调查显示，腐烂发生率的最大百分比发生在 7 月份。气候研究部 1979 年至 2018 年的观测降雨数据显示年际降雨变率趋势不显着；然而，它表现出低变化和7月份降雨量的显着减少趋势。对山药样品进行的致病性测试证实，真菌、细菌和线虫的腐烂是剧毒病原体，而腐烂的山药的营养品质也得到了说明。月降雨量与腐烂发生率呈正相关（r= 0.84，显着性为 99%吨-测试）。正的特征影响值表明，月降雨量的增加（减少）对应于月腐烂发生率百分比的增加（减少）。因此，显着减少的降雨减少了腐烂发生率，从而增加了该时期的山药年产量。选定的协调区域降尺度实验-非洲模型和集合平均值在历史实验中显示出与观测降雨量的良好一致性。代表性浓度路径 (RCP) 4.5 和 8.5 中的偏差校正输出的效率表明改进的“合理”性能。对 7 月降雨的偏差校正预测显示，两个 RCP 都有增加的趋势，这表明腐烂发生率可能会增加，从而导致山药年产量下降。这些发现对于维持全球粮食供应至关重要。