Current knowledge on Amaranthus spp.: research avenues for improved nutritional value and yield in leafy amaranths in sub-Saharan Africa. Euphytica

Abstract In the past 20 years, very little progress has been achieved in reducing food insecurity, child malnutrition and hunger in Africa. Under-nutrition and micronutrients deficiencies are widespread and affect mainly women and children. To address these problems, increased consumption of African leafy vegetables is promoted as sources of both micronutrients and bio-active compounds. Widely promoted African leafy vegetables include Amaranthus spp., a taxonomic group cultivated worldwide. Species of this genus are used as pseudo-cereals in Europe and America, and are mostly planted as vegetables in Africa. Amaranthus has been rediscovered as a promising food crop mainly due to its resistance to heat, drought, diseases and pests, and the high nutritional value of both seeds and leaves. Leaves are rich in proteins and micronutrients such as iron, calcium, zinc, vitamin C and vitamin A. All parts of the plant are used as medicine to heal many diseases in African communities. This paper focuses on leafy amaranths traditionally utilized on the continent. It briefly reviews the current knowledge on taxonomy, ecology, nutritional and nutraceutical value, production and cultivation systems, reproductive biology, genetic resources and breeding of amaranths. Species of interest include: A. blitum, A. caudatus, A. cruentus, A. dubius, A. hypochondriacus, A. spinosus, A. thunbergii, A. tricolor, and A. viridis. Research and development opportunities on nutritive and nutraceutical properties, production and commercialization, taxonomic evaluation and breeding perspectives were explored

Origin-dependence of variation in seed morphology, mineral composition and germination percentage in Gynandropsis gynandra (L.) Briq. accessions from Africa and Asia

Background: Spider plant [Gynandropsis gynandra (L.) Briq.], an economically promising African leafy vegetable, characterized for leaf yield components and nutritive quality, exhibits poor seed germination that hinders a wider expansion of the crop in urban and periurban horticultural systems. So far, there is little information pertaining to seed morphological traits and mineral elements content that may be associated with higher seed germination. This research investigated the hypothesis that spider plants from different geographical areas exhibited differences in seed mineral composition, morphological traits, and germination capacity. To this end, twenty-nine accessions of Gynandropsis gynandra from West and East-Southern Africa, and Asia were screened for variation in seed size (area, perimeter, length, width), 10-seed weight, mean germination time, germination percentage and mineral content variations. The scanning electron microscopy (SEM), light microscopy and energy dispersive spectroscopy (EDS) solution were used to study seed morphology and mineral composition. Results: We show for the first time the external and internal structure of the seeds of Gynandropsis gynandra and measured eight mineral elements, including carbon (C), oxygen (O), magnesium (Mg), aluminium (Al), phosphorus (P), sulphur (S), potassium (K) and calcium (Ca). The accessions differed significantly (p < 0.001) with respect to seed size (area, perimeter, length, width), 10-seed weight, mean germination time and germination percentage. The hierarchical cluster analysis based on fourteen variables grouped the accessions into three distinct clusters, partially dependent on their geographical origin. Asian accessions exhibited smaller seeds and recorded higher values in terms of germination percentage. West African accessions had bigger seeds but with lower germination percentage. Variation in minerals such as potassium, carbon, and calcium content showed different patterns according to geographical origins. Conclusion: Smaller seeds in G. gynandra exhibited better germination capacity. The Asian germplasm is a potential source of cultivars with a higher germination percentage for improving seed quality in the species.</p

Enabling effective maize seed system in low-income countries of West Africa: Insights from Benin

Introduction Access to high-quality seeds remains a key constraint to the intensification of crop production in low-income countries. In this study, we analyzed maize seed production and distribution systems in Benin to identify leverage points for effective seed systems, a prerequisite for improving maize production. Methods Semi-structured interviews were conducted with 81 seed producers selected in seven municipalities across the three phytogeographical zones of Benin. Key informant interviews were also conducted with ten public and private stakeholders involved in maize seed systems in Benin. Results and discussion Findings showed that the legal and institutional frameworks governing seed systems in Benin were recently reinforced with a national seed policy, the creation and operationalization of the National Committee of Plant Seeds and the existence of regulations and rules on the production, quality control, certification, trade, and packaging of seeds. In addition, enabling conditions to facilitate the involvement of the private sector have been greatly improved with the revision of modalities for obtaining approval for the production and distribution of seeds in Benin. While the seed sector is improving and both public and private stakeholders are involved in maize seed production and distribution, synergies among stakeholders need to be strengthened. Strengthening business and marketing skills of seed producers through training and promoting the comparative advantages of improved seeds in increasing yield and production among maize farmers could be a promising avenue. Connecting seed producers with maize farmers' organizations coupled with ICT-based agro-advisories could boost the development of the maize seed sector, and ultimately the maize value chain

Developing improvement strategies for management of the Sisrè berry plant [Synsepalum dulcificum (Schumach & Thonn.) Daniell] based on end-users’ preferences in Southern Nigeria

Synsepalum dulcificum is a valuable horticultural and lesser-known crop, famous for the uniqueness of its taste modifying properties, which is candidate for genetic improvement in West Africa. Semi-structured interviews were conducted with 100 respondents purposively selected to analyze the current production systems and constraints as well as to document the farmers’ and consumers’ preferences for breeding traits in Southern Nigeria. The results showed that none of the investigated farmers applied all required crop management practices to produce the species (land cleaning before establishment, pegging and lining, holing, base manure application, crop irrigation, weeding, pruning, fertilizers application, and pests and diseases control). Farmers were grouped into three clusters based on crop management practices. There was a strong and highly significant agreement among farmers (Kendall’s W = 0.8, p &lt; 0.001) that bush fire, poor plant growth, drought, pests, and parasitic weed were the five most important constraints in Southwest Nigeria. In Southeast Nigeria, damage by insects and birds, poor seed germinability and poor knowledge of cultivation technics were the most important constraints challenging production. Farmers’ agreement around these constraints was moderate but highly significant (Kendall’s W = 0.6, p &lt; 0.001). Overall, the top three desired breeding traits by farmers included: high growth rate, extended fruit shelf-life, and high fruits yield while the top three consumer’s preferences included: high miraculin potency (long lasting action of the miraculin), fruit glossiness, and high metabolites content. However, cultural specificities were detected in these preferences with a higher agreement in Yoruba farmers’ preferences compared with their counterparts Igbo. The Igbo consumers showed a higher concordance in their traits’ preferences than the Yoruba consumers. These findings pave the way for an informed cultivar development for the Sisrè berry plant in Nigeria and expand knowledge on end-users’ preferences for the species in West Africa

Farmers’ Perception of Viral Diseases and Their Management in Pepper (Capsicum spp.) Production in Benin

Pepper (Capsicum spp.) is an important solanaceous cash crop in Benin; however, productivity is limited due to several key constraints, especially diseases caused by viruses. We sought to understand farmers’ perceptions of viral diseases, management strategies deployed, and to identify the virus population affecting pepper production in Benin. To assess farmers’ perceptions and management of viral diseases, a survey was carried out in four agroecological zones of Benin. A total of 144 pepper farmers were interviewed using the snowball method. A total of 52 pepper leaf samples with virus-like symptoms were collected and diagnosed by reverse-transcriptase polymerase chain reaction (RT-PCR) or PCR. Pepper production systems varied across agroecological zones (P ≤ 0.001) with a predominance of farms practicing monoculture (82%). The majority of farmers (89%) indicated that pests and diseases were the main constraints to increased production. Cucumber mosaic virus (92% of the total samples), Pepper vein yellow virus (52%), and Pepper veinal mottle virus (50%) were the major viruses detected in pepper fields in Benin. There were both single (29%) and mixed (71%) infections of the viruses, suggesting that mixed infections are common for pepper in Benin, confounding efforts to reduce virus infections. Nearly 100% of the farmers surveyed were not aware of these viral diseases. They also could not directly relate symptoms of virus infection to the presence of aphids, whiteflies, or thrips. Farmers relied primarily on synthetic insecticides (93%) to control virus vectors. Interestingly, some farmers applied commercial (12%) and homemade (17%) biopesticides, with neem-based preparations being the most widely used. A total of 15% of farmers used companion cropping with maize, mint or basil and 43% of farmers used crop rotation as a cultural management practice to control viral disease and vector pressure in pepper fields. The implications of this work include the importance of training farmers and extension agents on diagnosis of viruses and their vectors causing viral diseases. This study provides baseline information for the development of host-resistant cultivars and deployment of integrated pest management strategies for pepper in Benin to reduce farmer losses

Fruit and vegetable biodiversity for nutritionally diverse diets: Challenges, opportunities, and knowledge gaps

Planetary health brings together intrinsically linked issues of human health and natural systems. This paper reviews evidence of how agrobiodiversity underpins dietary diversity for current human populations in the context of fruits and vegetables, and ways to maintain and improve these for future generations. Both the conservation and sustainable use of fruit and vegetable biodiversity and the consumption of diverse diets are sub-optimal, and in many contexts getting worse. Agrobiodiversity and nutrition are linked through food availability, access, conservation and consumption, with potential win-wins but notable trade-offs for policy and action through time, place, agrobiodiversity use, and equity. We pinpoint research gaps and call for inclusive deliberation for action

Nutraceutical Uses of Traditional Leafy Vegetables and Transmission of Local Knowledge from Parents to Children in Southern Benin

This study assessed differences on the uses and transmission of traditional knowledge (TK) about three traditional leafy vegetables (Crassocephalum crepidioides (Juss. ex Jacq.) S. Moor, Launaea taraxacifolia (Willd.) Amin ex C. Jeffrey, and Vernonia amygdalina Del.) of the Asteraceae family over two generations in three villages: Adjohoun, Dangbo, and Pob&egrave; (southern Benin). Individual semi-structured ethnobotanical interviews of 360 respondents were conducted in the villages with young girls, boys, and their two parents. The relative frequency of citation, use value, and Jaccard similarity index were used for data analyses. Vernonia amygdalina was the most commonly known and used vegetable in all villages, while L. taraxacifolia was confined to Pob&egrave;. Factors such as village of survey, generation, and gender affected the use value of the species, but the patterns of recognition and cultivation were species-specific. Leaves were the most used plant part. Traditional knowledge was largely acquired from parents (90% of citation), and both mothers and fathers transmitted a similar amount of knowledge to their progenies. The knowledge on V. amygdalina was transmitted to a larger scale than knowledge of C. crepidioides and L. taraxacifolia. Irrespective of the species, transmission of TK was higher in Pob&egrave;. Gender and generation knowledge dynamic hypothesis is species-specific. TK transmission was species-specific too and may be linked to the local importance and use of those resources. These findings will inform strategies and programs for the sustainable use and conservation of leafy vegetables in local communities and national research and development institutions

Enhancing growth and leaf yield in Gynandropsis gynandra (L.) Briq. (Cleomaceae) using agronomic practices to accelerate crop domestication

Gynandropsis gynandra (Spider plant) is an African leafy vegetable with several nutritional benefits, considered as a weed or cultivated crop. The species is of interest for local communities though knowledge on agronomic practices need to be improved. This study assessed the effects of two seedling ages at transplanting (two weeks and three weeks after sowing), three planting densities (444,444; 250,000 and 166,666 plants ha−1), three second harvest timings (one week, two weeks and three weeks after the first harvest) and three cutting heights (≤10 cm; between 10 and 15 cm and ≥15 cm) on growth and yield in Gynandropsis gynandra. The results revealed that two weeks and three weeks old seedlings could be used for the species cultivation. Seedling age, planting density and consecutive cutting time had significant effects on growth and biomass yield. Increasing planting density decreased plant growth but increased edible biomass yield. Planting density of 444,444 plants ha−1 gave the highest biomass yield (29 t ha−1). Cutting height greater than 15 cm favored a better regrowth and higher biomass yield. Harvesting plants two weeks after the first harvest gave more biomass yield but yield decreased from the first harvest to the second one. These results offer new insights into horticultural practices and the expanding of spider plant cultivation in urban and periurban areas