Biotic and abiotic constraints jeopardize the expansion of common bean (Phaseolus vulgaris L.) cultivation to the Cameroon warmer lowlands. The crop is traditionally perceived as a cooler region crop unsuited for the humid tropical areas. We surveyed 78 farmer's fields during the 2015 and 2016 growing seasons, across 7 sub-divisions in the lowland agro-ecological zone of the Centre Region of Cameroon, to document the occurrence of the common bean root rot (BRR) epidemic, the identification of causal pathogens, as well as related agro-ecological variables. We found that BRR occurred in all the surveyed farmer's fields, with disease incidence ranging from 7.4% to 92.4% and disease severity from 3.7 to 9 (On the 1–9 disease rating scale). The disease distribution was closely related to tillage, cropping systems, plant age and variety and physiological status in both seasons. The simple linear regression model and the Pearson correlation revealed significantly negative correlations between the soil pH and phosphorus content, and the disease incidence and severity. Five causative fungal genera were identifies, with varying occurrence: Fusarium spp. (65.4%), Pythium spp. (4.2%), Sclerotium spp. (5.1%), and Macrophomina spp. (8.2%), with Fusarium being the most represented and widespread pathogen irrespective of sampling field and season. Fusarium occurred singly, or in complex with the other pathogenic fungal genera. This study provides clear evidence of high prevalence of BRR disease in the humid lowlands of Cameroon, and suggests deep ploughing and phosphoric fertilizer amendment with basic soil for managing BRR in lowland agro-ecosystems.

生物和非生物限制会危害普通豆（菜豆）的繁殖L.）种植到喀麦隆温暖的低地。传统上，这种作物被认为是较凉爽的地区，不适合潮湿的热带地区。我们在2015年和2016年生长季期间对喀麦隆中部地区低地农业生态区的7个分区的78个农民田地进行了调查，以记录普通豆根腐病（BRR）流行的发生，病原体以及相关的农业生态变量。我们发现BRR发生在所有调查过的农民田地中，疾病发生率从7.4％到92.4％，疾病严重度从3.7到9（在1–9疾病等级量表上）。在两个季节中，病害分布与耕作，耕作系统，植物年龄以及品种和生理状况密切相关。简单的线性回归模型和Pearson相关性揭示了土壤pH和磷含量与疾病发病率和严重程度之间的显着负相关。鉴定了五个致病性真菌属，并有不同的发生率：镰刀菌属 （65.4％），腐霉属。（4.2％），菌核菌属。（5.1％）和巨光藻属。（8.2％），镰刀菌是最有代表性且分布最广的病原体，与采样场和季节无关。镰刀菌单独或与其他病原真菌属一起发生。这项研究提供了明确的证据，证明喀麦隆湿润低地的BRR病高发，并建议在低地农业生态系统中进行深耕和用基础土壤改良磷肥，以管理BRR。