Farmers' Knowledge and Perception on Kersting's Groundnut (Macrotyloma geocarpum) Diseases and Pests in Benin

Kersting's groundnut (Macrotyloma geocarpum) is a neglected and underutilized legume crop in Benin and is subject to several constraints, including diseases and pests, which constitute a bottleneck to its production. A randomized semistructured interview and participant observation survey were conducted in September 2020 to identify the perception and knowledge of farmers regarding diseases and pests affecting Kersting's groundnut. Thus, 84 farmers were surveyed in three agroecological zones where Kersting's groundnut is produced in Benin. After observation of disease symptoms through photographs, about 62% of the respondents stated that they observed diseases with low to medium incidence, but nearly 93% of the respondents did not recognize these symptoms as due to diseases. However, although 83% of the respondents recognize diseases as a constraint, all respondents (100%) do not adopt any control strategy against these diseases, due to the lack of knowledge about management practices, and are linking the symptoms to mystical phenomena, heavy rainfall, or strong sunlight. As for pests, about 69% of the respondents observe them in their fields but 80% of the respondents do not consider them as a constraint in Kersting's groundnut production, although 17 and 26% of the respondents claim to observe locusts and caterpillars, respectively, in their fields. No control methods are applied against these pests. Extensive extension work is needed to raise awareness of the diseases and pests of this crop while seeking effective control strategies.

Metabolite Fingerprinting of Kersting's Groundnut [Macrotyloma geocarpum (Harms) Maréchal & Baudet] Seeds Using UPLC-qTOF-MS Reveals the Nutraceutical and Antioxidant Potentials of the Orphan Legume

The identification and subsequent quantification of phenolic compounds in plants is the first step toward harnessing their associated nutritional and health benefits. Due to their diverse phenolic compound compositions, grain legumes are known for their high nutritional and health values. The aim of this study was to assess the inter-variations in chemical composition, phytochemical content, and antioxidant capacity of seed extracts from eight Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] landraces. The chemical profiles were evaluated using UPLC-qTOF-MS. Total phenolics and flavonoids content were determined by the Folin-Ciocalteu and aluminum chloride methods, respectively. The antioxidant capacities in the forms of DPPH and ABTS were evaluated using spectrophotometric methods. Principal component analysis was used to define similarities/differences between the landraces. Based on untargeted metabolomics analysis, 57 metabolites were identified, with phenolics, triterpenes, fatty acids, and sphingolipids being the most predominant. The results showed that the black seeded KG1 (Puffeun) had the highest total phenolic (9.44 mg GAE/g) and flavonoid (3.01 mg QE/g) contents, as well as antioxidant capacity (9.17 μg/mL and 18.44 μg/mL based on DDPH and ABTS assays, respectively). The concentrations of ferulic acid hexoside, procyanidin B2, eryodictyiol-7-rutinoside and quercetin pentoside ranged from 51.78–441.31, 1.86–18.25, 3.26–13.95 to 5.44–63.85 μg/mg, respectively. This study presents a useful report on the phytochemical characterization of Kersting's groundnuts and shows that the grains can be used as a source of nutraceuticals for human consumption.