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Spider plants (Gynandropsis gynandra, L. Briq.) are a semi-wild vegetable reported to have high nutritional, medicinal, insecticidal, and cultural values, yet continue to be neglected in research. The study was undertaken to investigate indigenous knowledge and utilization of the species in five regions of northern Namibia. Three tools were used; (i) focus group discussion, (ii) semi-structured interviews involving a random selection of 100 farming households and 24 consumers, and (iii) key informant interviews involving four agricultural staff and two open-market supervisors. Data were subjected to descriptive statistics, inferential, and cluster analyses. The study found that farming households and consumers placed higher nutritional, sociocultural, and medicinal values in spider plants than any other vegetable. Ranking of utilization traits, such as nutritional, sociocultural, and medicinal use, revealed three clusters of sociolinguistic groups associated with geographical region. The vegetable was sold and used in most cultural, traditional, and religious functions as a relish, as a source of honor, to bring luck, and for protection. The diverse uses and value placed on spider plants could offer an opportunity for the development of technologies for enhancing their domestication, production, and utilization. It is recommended that follow-up studies be carried to identify specific sociocultural and geographic factors affecting the use of spider plants.

Increased public awareness of healthy foods and healthy living, coupled with escalating medicinal costs and recent advances in research and technology, has sparked a paradigm shift to nutraceuticals, which guarantee human health and disease prevention. Spider plant (Gynandropsis gynandra) contains dietary phytochemicals with high nutritional and medicinal properties that can contribute to healthy living. A study was conducted to identify spider plant (Gynandropsis gynandra (L.) Briq.) accessions with superior levels of dietary phytochemicals and anti-oxidative activity for use in nutraceutical breeding. Thirty-three accessions of spider plant, representing a wide genetic diversity based on geographic areas of origin (Asia, East Africa, Southern Africa, and West Africa), were used. Total phenolic acids, tannins, and anthocyanins were extracted and quantified using the Folin-Ciocalteau colorimetric, spectrophotometric, and pH differential methods, respectively. Antioxidant activity was determined using phosphomolybdenum method. Results showed significant variation in levels of total phenolic compounds, tannins, anthocyanins, and antioxidant activity (P < 0.05) amongst the spider plant accessions and regions of origin; ODS-15-037 (464 mg TAE/g DW), ODS-15-053 (270 mg GAE/g DW), and BC-02A (127 mg cyanidin-3-glucoside/g DW) had the highest levels of total tannins, phenolic compounds, and anthocyanins, respectively. Antioxidant activity was high in ODS-15-053 (492.2 mg AAE/100 g DW), NAM 2232 (445.3 mg AAE/100 g DW), and NAM-6 (432.5 mg AAE/100 g DW). On average, West African accessions had significantly high tannin concentrations (239 mg TAE/g DW), while Southern Africa accessions contained significantly high anthocyanin content (58.9 mg cyanidin-3-glucoside/g DW). The superior accessions are potential candidates for use in nutraceutical breeding, while the regions of origin could be used as gene pools for specific phytochemicals for improving dietary supplements of nutraceuticals. The strong antioxidant activity exhibited by spider plant accessions suggests the presence of compounds responsible for scavenging free oxygen or nitrogen radicals. Further studies are recommended to identify the chromosomal regions that contain genes controlling the dietary nutraceuticals in the genetic materials and to determine their association with foliage yield and other phenotypes, which can be utilized in spider plant improvement.

Knowledge on the diversity and domestication levels of the spider plant (Gynandropsis gynandra) has the potential to affect pre-breeding for client-preferred traits, yet information is scarce in Namibia due to limited research. We investigated indigenous knowledge on the species diversity and domestication levels in the regions of Kavango West, Ohangwena, Omusati, Oshana, and Oshikoto of northern Namibia. Semi-structured interviews involving 100 randomly selected farming households, four key informant interviews, and a focus group discussion were conducted. Descriptive and chi-square tests were conducted using IBM SPSS version 20. Out of the possible four morphotypes, the results suggested that only one with green stem and green petiole existed and was associated with soils rich in organic manure. Spider plant abundance was reported to be on the decline, due to declining soil fertility. On a scale of 0 (wild species) to 6 (highest level of domestication), an index of 1.56 was found and this implied very low domestication levels. Furthermore, the study found significant differences in the trends of domestication across the sociolinguistic groups (χ2 (12, N = 98) = 46.9, p < 0.001) and regions studied (χ2 (12, N = 100) = 47.8, p < 0.001), suggesting cultural and geographical influences. In conclusion, the findings constituted an important precedent for guiding subsequent pre-breeding efforts.

Summary In sub-Saharan Africa (SSA), farmers intercrop common beans with maize but apply inorganic or organic fertilisers targeting only maize. Effects of this practice on bush bean yield have not been fully evaluated with respect to input use and compatibility when intercropped with maize. An on-farm trial managed by smallholder community members was conducted to assess the influence of various soil fertility management options and cropping systems on the yield of two bush bean genotypes (SER45 and SER83) in two agro-ecological zones of Malawi. The farmer-managed trials were laid out in split-plot design, with the bean genotypes as main plots and a combination of the soil fertility management options (i.e., no input, manure, fertiliser and fertiliser + manure) and cropping systems (i.e., sole crop and intercrop) as subplots. The trials were affected by terminal drought and dry spells, but results show that manure and fertiliser application enhanced the resilience of the drought-tolerant bean genotypes. The genotype SER45 was responsive to manure application in the sole crop, giving a 44.4% yield increase over no-manure application. In sole cropping with fertiliser plus manure, bean yields improved by 40.1% for SER45 and 78.3% for SER83 relative to the no-input control. Although sole cropping had higher bean yields, the treatment with manure and fertiliser had a higher land equivalence ratio for intercrop of 1.54 for SER45 and 1.32 for SER83 over sole cropping. These results show that, under smallholder farmer management, the climate adaptability of bush bean genotypes could be enhanced by the combined application of organic and inorganic fertilisers in maize–bean intercrop. The combined application also enhances whole-farm productivity of the common maize–bean intercrop practice than monocrop, hence is of benefit to most low-input smallholder farmers of SSA.

Spider plant (Gynandropsis gynandra (L.) Briq.) is among the most important African Leafy Vegetables (ALVs) as a source of essential nutrients with the potential of contributing significantly to household food and nutritional security and mitigation of hidden hunger. Nevertheless, the vegetable is considered an orphan crop and its production is challenged by inadequate research to identify and improve traits preferred by smallholder farmers. The research was conducted to identify the main challenges impacting the production of spider plants and identify traits preferred by smallholder farmers in northern Namibia and central Malawi for use in demand-led crop improvement. Semi-structured interviews involving a random selection of 197 farming households from five regions of northern Namibia and three districts of central Malawi were conducted. In addition, six key informant interviews and four focus group discussions were conducted to triangulate the findings. Data were analyzed using IBM SPSS version 20. Fischer's exact test was used to test for independence in the ranking of production constraints and agronomic traits, while Kendall's Coefficient of Concordance (W) was used to measure agreement levels in the ranking across the countries. Farmers indicated lack of seed, poor soil fertility, poor seed germination and drought as the main production challenges across the two countries. Production constraints were ranked differently (p &lt; 0.001) across the study sites suggesting the influence of biophysical and socio-economic factors associated with production. High yield and drought tolerance were considered the most important agronomic traits among the smallholder farmers in both countries. The findings of this study are useful for designing demand-driven pre-breeding trials that prioritize the needs of the end-users. Demand-led breeding has the potential to stimulate the production and utilization of spider plant, hence contributing to household food and nutritional security.