Ethno-ecological knowledge of tiger nut (Cyperus esculentus L.) across contrasted climate zones: uses, diversity, production system, and perception of climate change in Togo (West Africa).

backgroundCyperus esculentus a perennial sedge, has been cultivated since ancient times for its nutritious and versatile tubers, which are used in cooking, traditional medicine, and various industries. Despite its potential, the crop remains underutilized in Togo and is grown in limited areas. Moreover, there is a lack of information on its genetic diversity, cropping systems, uses, and the impact of climate change on its productivity; factors essential for effective breeding and sustainable cultivation. This study aimed to document and compare existing knowledge on the uses and production systems of tiger nuts, as well as tiger nut producers' perceptions of climate change and its impact on tiger nut cultivation in two regions of Togo with contrasting climatic conditions.

methodsA total of 206 tiger nut producers from six ethnic groups were selected across 26 villages located in the Savanes region (Sudanian climate) and the Plateaux region (Guinean climate) were selected following the snowball method during a survey conducted from July to September 2023. Data on tiger nut uses, diversity, production systems, and producers' perceptions of climate change and its impact on the species' productivity were collected using participatory rural appraisal methods. The data were analyzed using descriptive statistics, Fisher's Exact Test to examine the relationship between region and sociodemographic factors, and multinomial logistic regression to identify which sociodemographic characteristics influence tiger nut growers' perceptions of climate change and their views on its impact on production.

resultsA significant difference was observed in the gender distribution of tiger nut producers between the two regions. In the Savanes region, most producers were male (75%), whereas in the Plateaux region, most were female (84%). The area dedicated to tiger nut production also varied significantly between the regions. In the Savanes region, no more than 0.25 ha was allocated to the crop, whereas in the Plateaux region, 58% of producers dedicated more than 0.25 ha of their land to tiger nut cultivation. Seven distinct uses were identified: tuber consumption, commercialization, medicinal applications, soil fertilization, traditional beverage preparation, weed control, and livestock feeding. The last three were reported exclusively in the Savanes region. Eight major constraints were identified across the two regions. The most critical in the Plateaux region was harvesting difficulties, while in the Savanes region it was pest attacks. Regarding climate change, chi-square tests showed a significant association between climatic zones and farmers' perceptions, as well as between regions and the reported effects of climate change on tiger nut cultivation (P < 0.001). Perceived climate change indicators included irregular rainfall, delayed onset of rains, drought spells, and early rainfall. Reported effects on the crop included reduced yields, abnormal growth patterns, premature yellowing of leaves, seedling desiccation, and small tubers.

conclusionThe ethno-ecological knowledge captured in this study provides a foundational resource for the sustainable management and conservation of tiger nut, and for the development of effective breeding strategies in Togo.