<i>In-situ</i> morphological characterisation, adoption and whitefly populations of cassava ( <i>Manihot esculenta</i> Crantz) grown in Cameroon

Abstract Background: Cassava ( Manihot esculenta ) is vital for food security and income generation in Cameroon. However, its genetic variability remains unexplored, cultivation faces pest and disease constraints, and little is known about the adoption, characterisation, and whitefly resistance of cultivars grown in the country. Methods: Nationwide field surveys were conducted across 342 farms to assess local naming system, adoption, leaf morphological characterisation and whitefly populations of cultivars. Leaf morphological characterisation was performed on local landraces using six descriptors of cassava plants aged 3–6 months. Whitefly adult colonisation was evaluated on 248 cultivars based on field infestation. Results: Various local names and knowledge on improved varieties and local landraces were documented. The adoption rate of improved cassava varieties was 55.58%, but the mean land area cultivated with local landraces (0.53 ha) was higher than that of improved varieties (0.32 ha). High phenotypic variability was observed, with 74 distinct morphotypes identified among 187 local landraces. Three principal components accounted for 82.76% of the total variation. Cluster analysis revealed six clusters with no geographical structuring among morphological groups. No adult whiteflies were recorded on 8 cultivars and whiteflies were more abundant on improved varieties (7.63 ± 12.93) than on local landraces (5.58 ± 9.44). Conclusion: These findings inform strategies to enhance adoption of improved cassava varieties, support conservation, management, and genetic improvement of the crop.