Abstract：
Epidemic of Cashew Fusarium wilt disease (CFWD) has been a continuous focal challenge in the cashew farming, in Tanzania. Limited to edaphic conditions as a major factor in its epidemic, the current study aimed to assess the habitat-disease relationship. Purposive surveys involving assessment of disease prevalence and habitat compositions were conducted across four landscapes of southeastern zone from 2019 to 2023. Findings revealed a widespread of CFWD across diversified landscapes possessing varying habitat characteristics, mainly cultivated land with mature cashew, brownish sand loamy soils, grassland or shrub vegetation, seasonal river streamlines and natural water wells. The highest disease incidence and severity were noted at Nachingwea/Masasi plain (99.28:88.34%) followed by Liwale inland plain (98.64:89.3%), Coastal zone (72.72:59.83%) and Tunduru dissected plain (62.13:54.54%). The habitat characteristics were strongly similar within the landscape (0.86-Jaccard index) except between villages of the coastal zone (0.71-Jaccard index). Across landscapes, Nachingwea/Masasi plains and the Coastal zone were strongly similar to Tunduru dissected plain (0.63-1.0-Jaccard index), but strongly dissimilar with the Liwale inland plain (0.67-0.70- Jaccard distance). Furthermore, the presence of greater than 0.5 suitability indices across landscapes were revealed, with Liwale inland plain having strongest suitability index of 0.743 followed by Coastal zone (0.681), Tunduru dissected plain (0.617) and Nachingwea/Masasi plain. Significantly, the habitats had an increase of 0.1 suitability index, and positively correlated with disease prevalence by triggering disease incidence of 13.9% and severity of 31.4%. The study for the first time revealed the presence of an association between disease prevalence and landscape habitat characteristics of southeastern, Tanzania; paving the way to inclusive thinking of habitat as one of the drivers in the prevalence of fusarium wilt disease of cashews. Further research on the genetic coevolution of Fusarium oxysporum across landscapes to strengthen disease risk management in the cashew industry is recommended.
摘要：
腰果枯萎病（CFWD）的流行一直是腰果养殖中的一个持续焦点挑战，在坦桑尼亚。限于疫情作为其流行的主要因素，本研究旨在评估栖息地与疾病的关系。从2019年到2023年，在东南部地区的四个景观中进行了涉及疾病患病率和栖息地组成评估的目的性调查。研究结果表明，CFWD在具有不同栖息地特征的多种景观中普遍存在，主要是成熟腰果的耕地，褐色砂质壤土，草地或灌木植被，季节性河流流线和天然水井。疾病发病率和严重程度最高的地区是Nachingwea/Masasi平原（99.28：88.34％），其次是Liwale内陆平原（98.64：89.3％），海岸带(72.72:59.83%)和东杜鲁解剖平原(62.13:54.54%)。除了沿海地区的村庄之间（0.71-Jaccard指数）外，景观中的栖息地特征非常相似（0.86-Jaccard指数）。横跨风景，Nachingwea/Masasi平原和沿海地区与Tunduru解剖平原非常相似（0.63-1.0-Jaccard指数），但与Liwale内陆平原强烈不同(0.67-0.70-Jaccard距离)。此外，揭示了整个景观中存在大于0.5的适宜性指数，Liwale内陆平原的适宜性指数最强，为0.743，其次是沿海地区（0.681），Tunduru解剖了平原（0.617）和Nachingwea/Masasi平原。重要的是,栖息地的适宜性指数增加了0.1，与疾病患病率呈正相关，触发疾病发生率为13.9%，严重程度为31.4%。这项研究首次揭示了东南部的疾病患病率与景观栖息地特征之间存在关联，坦桑尼亚；为将栖息地作为腰果枯萎病流行的驱动力之一的包容性思维铺平了道路。建议进一步研究跨景观的尖孢镰刀菌的遗传协同进化，以加强腰果行业的疾病风险管理。
