Relative to the informal seed systems, quality declared seed (QDS) system provides higher quality seed. Thus, it offers smallholder farmers an opportunity to access seeds of new and improved varieties more conveniently and efficiently. However, various challenges limit growth of QDS production in many subscribing countries. Therefore, this study assesses economic viability and sustainability of QDS system for common bean, groundnuts and sorghum in Tanzania. We find that QDS production is profitable, with positive profit margins and a benefit-cost ratio greater than one. QDS is primarily sold at the farmgate, with <10% sold through formal outlets or shops, posing quality and traceability challenges. QDS system avails to smallholder farmers diverse and improved varieties at affordable costs and in a timely manner. Weak regulations, inadequate inspections, low producer license renewal or registration may slow gains in the QDS business. We recommend developing marketing infrastructure to integrate private sector players like grain traders and processors, and enhancing public-private partnerships for early generation seeds and certified seeds needed for QDS production. We also suggest revising and updating the QDS training curriculum to include business entrepreneurship and marketing modules and revising existing laws to support faster QDS sector growth.

Common bean (Phaseolus vulgaris L.) is a key food legume contributing to nutrition, food security, and income in Burundi. However, limited information on genetic variability, trait relationships, and genotype × environment interaction (GEI) constrains its effective use in breeding programs. This study assessed phenotypic variability, genetic parameters, trait associations, and breeding potential of bush and climbing bean genotypes. A total of 167 genotypes (83 bush and 84 climbing) were evaluated across multiple environments. Growth habits were analyzed separately using combined ANOVA, REML-based variance components, correlation, path analysis, and GGE biplot approaches. Combined ANOVA revealed highly significant (P < 0.001) genotypic effects and strong GEI. REML analysis showed higher heritability in bush beans, particularly for plant height (H² = 0.45) and hundred seed weight (H² = 0.51), whereas climbing beans exhibited lower estimates (0.03–0.38). Correlation and path analyses identified number of pods per plant (NPP), harvest index (HI), and hundred seed weight (HSW) as major contributors to grain yield. In bush beans, days to maturity, plant height, and HI had stronger direct effects, while in climbing beans NPP, HI, and HSW were more influential. GGE biplot analysis showed greater yield stability in bush beans, whereas climbing beans exhibited stronger genotype specialization. Mean grain yield exceeded 2700 kg ha⁻¹ in elite bush genotypes and 2500 kg ha⁻¹ in climbing types. BLUP analysis identified stable, high-yielding genotypes including Amahatanyovu, Magoma, Musosi, and Ruvyibushabatama. These findings highlight distinct genetic architectures between growth habits and provide guidance for breeding, though further validation is required.

One of the most pressing challenges of our time is ensuring sustainable food systems amid environmental, socioeconomic and climatic changes. Common bean farming plays a central role in enhancing food security and alleviating malnutrition, yet its productivity is severely constrained by herbivorous pests, especially bean flies, Ophiomyia spp. (Diptera: Agromyzidae). Despite their potential to cause up to 100 % crop yield loss, knowledge on their distribution and management remains limited. In this study, we conducted a comprehensive review of bean fly ecology and management strategies, drawing from peer-reviewed and grey literature from major academic databases (e.g., Scopus, Web of Science, ScienceDirect) and complementary sources. Our findings highlight three key species—Ophiomyia phaseoli (Tryon), Ophiomyia spencerella (Greathead), and Ophiomyia centrosematis (Greathead)—each exhibiting distinct spatial and temporal distribution patterns. The species O. phaseoli and O. centrosematis are cosmopolitan, predominantly found in warm low-to mid-altitude regions, whereas O. spencerella is restricted to the tropical highlands of East Africa. The most significant yield losses are attributed to O. phaseoli and O. spencerella, while O. centrosematis occurs less frequently and has comparatively lower economic impact. Early sowing, increased precipitation, and greater varietal diversity are generally associated with lower infestation rates, whereas shortened off-season intervals and high planting densities create favourable conditions for population build-up. Synthetic pesticides remain the mainstay of bean fly control, yet they offer short-term benefits and pose considerable long-term risks to ecosystem integrity and human health. We advocate for research on sustainable bean fly management strategies that integrate ecological principles, safeguard ecosystem services, and sustain crop yields.

Climate change is projected to reduce land suitable for common bean cultivation in Sub-Saharan Africa. This poses serious risks to food security and livelihoods, especially as most farmers continue to grow older varieties under changing conditions. This study evaluated current and future suitability of common bean varieties in Tanzania by comparing older (>10 years) and newly released, market-preferred cultivars under a CMIP6 climate scenario. Suitability was analyzed for near-current (1970–2000) and future (2021–2040) periods using the Targeting Tool Kit and land suitability models in R. Model outputs were validated with 98.7% accuracy. By 2040, highly suitable areas are projected to decline by 4.9%, while low-suitability areas may expand by 31.2%. Older varieties (JESCA, UYOLE 03) experience the greatest reductions (–5.7%, –5.0%), whereas newer varieties show greater resilience. TARIBEAN7 shows no clear spatial advantage over Lyamungu 90. Although JESCA may decline under future climates, its strong environmental predictability makes it a valuable reference variety for breeding. Altitude, rainfall, and soil properties remain dominant factors shaping suitability. Findings highlight the need for climate-smart and area -targeted breeding, broader seed dissemination, and improved soil management to sustain production and resilience.

Introduction:Common bean (Phaseolus vulgaris L.) is a key source of dietary protein and micronutrients, in low- and middle-income countries. Improving both yield and micronutrient density requires a clear understanding of genotype (G), environment (E), and genotype-by-environment interaction (GEI) effects to support nutrition-sensitive breeding strategies. Methods:This study assessed the effects of G, E, and GEI on grain yield and micronutrient concentration using the Additive Main Effects and Multiplicative Interaction (AMMI) model. A total of 83 bush and 84 climbing common bean genotypes were evaluated across three locations and two cropping seasons (2024A-2024B) in Burundi. AMMI and GGE biplot analyses were applied to examine genotype performance, stability, and adaptation across environments. Broad-sense heritability was estimated for yield and micronutrient traits, and a multi-trait selection index (MTSI) was used to identify superior genotypes combining agronomic and nutritional attributes. Results:Combined AMMI-analysis revealed highly significant (p <0.001) effects of genotype and environment on grain yield, iron (Fe), and zinc (Zn), together with significant GEI for most traits. Significant genetic variation was observed for Fe (52.86-76.5 ppm in bush beans; 53.38-59.7 ppm in climbing beans), Zn (≈17-23 ppm), and grain yield (≈950-2240 kg ha-1). Several genotypes surpassed check varieties for Fe and Zn, though enhanced micronutrient levels were not consistently associated with high yield. AMMI and GGE biplots identified both stable, high-performing genotypes and those with specific environmental adaptation. Broad-sense heritability was high for Fe and Zn (h2 = 0.68-0.82) but low for yield (h2 ≈ 0.30-0.33). The multi-trait selection index (MTSI) effectively identified genotypes combining good yield and micronutrient density. Discussion:These findings highlight the importance of integrated multi-environment evaluation and multi-trait selection for developing high-yielding, micronutrient-dense common bean varieties adapted to diverse agro-ecologies.

Rapid genetic gain was achieved for cooking time in common bean based on multivariate genomic analysis, but forward predictive ability was low and phenotyping remains essential to secure genetic gain. Common beans (Phaseolus vulgaris L.) are a major source of protein and energy in sub-Saharan Africa, but their long cooking time (CKT) imposes social, economic, environmental and health burdens. This study aimed to accelerate genetic gain for shorter CKT while maintaining or improving other seed traits such as seed iron (Fe) and zinc (Zn) content, water absorption capacity (WAC) and 100-seed weight (SW100) across rapid cycles of early-generation genomic selection. Two related founder populations were selected from the African bean panel and intercrossed in 2020 (population A) and 2021 (population B), followed by rapid two-year cycles of augmented S0-derived family selection based on an index and optimal contributions selection. Best linear unbiased predictions (BLUPs) of breeding values were obtained from pedigree (ABLUP), genomic (GBLUP) and single-step (HBLUP) multivariate linear mixed model analysis across two cycles. Realised genetic gain from cycle 1 to cycle 2 was high for CKT (average -8.0 min y−1) and favourably correlated with WAC (average + 7.7

Common bean (Phaseolus vulgaris L.) is an important legume in Tanzania, providing food, nutrition, and income. Since 2017, Tanzanian bean production has increased significantly, driven by factors such as changing dietary preferences, market and consumer demands, population growth, and urbanization. However, adoption of improved bean varieties remains low (14%) due to limited information about farmers’ trait preferences for improved varieties. This study evaluated farmers’ preferences for common bean varieties using the tricot (triadic comparison of technology) approach, in trials across three diverse agroecosystems of Tanzania. Eighteen bean genotypes were tested with 372 farmers. Each farmer evaluated three genotypes, ranking them in order of preference, providing reasons for their choice. Men’s participation (53.9%) was higher than women’s (46.1%) in common bean trial establishment, management, and Participatory Variety Selection (PVS), indicating a greater involvement of men in bean production in Tanzania. Genotypes NUA 48, NUA 64, Sweet Violet, and VTT923-23-10 were identified as the top-performing genotypes in terms of yield and farmer preference. High yield, market preference, and disease resistance were key selection criteria. Cooking suitability with banana and compatibility for intercropping emerged as important farmer preferences, reported for the first time in Tanzania, suggesting the importance of incorporating these traits in future variety development. Gender-specific trait preferences were also observed, with women prioritizing post-harvest traits, while men and youth focused on agronomic attributes and marketability, respectively. These findings underscore the importance of incorporating culturally preferred, high-performing agronomic traits into breeding programs, and ensuring equal participation in variety selection by women, men, and youth. Such inclusive approaches are crucial for enhancing improved bean variety adoption rates and boosting crop productivity. Beyond the tricot approach to varietal selection, this study provides deeper insights into gender-differentiated trait preferences and contextual factors influencing adoption, offering evidence to guide more demand-driven and inclusive bean breeding strategies.

Common bean (Phaseolus vulgaris L.) has increasingly become an important cash crop in SSA. Africa is the second-largest producer of common bean, contributing about 25% of global output and US$3.84 billion annually in Sub-Saharan Africa. However 50% of current bean-growing areas could become unsuitable by 2050 and yield is expected to reduce by 30–40% as temperatures rise, with disproportionate impacts on women, who account for more than 60% of producers largely due to persistent social and structural barriers. This systematic review of 79 studies (2007–2026) synthesizes evidence on climate risks and adaptation pathways in common bean systems. While breeding programs have released varieties tolerant to heat, drought, and poor soils, varieties bred for excessive-rainfall tolerance and explicit spatial adaptation remain absent from research agendas. Neighboring countries have already released and traded broadly adapted varieties based on regional market potential, but the lack climate-resilient cultivars constrains scalable climate resilience. Women, who dominate production and small-scale trade, are particularly vulnerable. We therefore call for urgent realignment of agricultural research with evolving climate and market realities and propose two actionable priorities: 1. Integrate excessive rainfall adaptation into breeding and climate models. (2) Shift breeding strategies toward a more regionally coordinated approach to enhance adaptation of varieties with regional market potential; 3. Strengthen seed systems and grain markets for market-relevant varieties through a gender-responsive regional approach.

ABSTRACT Scaling improved bean varieties and complementary technologies are important to improve crop productivity incomes and food and nutrition security in Sub‐Saharan Africa. In Burundi and Zimbabwe, bean technologies were promoted through a demand‐led and public–private partnership model. While econometric approaches have been used to estimate the impact of enhanced technologies on farmers' livelihoods for a long time, no economic feasibility analysis has been done. Most analyses focus on farmers livelihoods, overlooking other value chain actors like traders, processors, and seed producers including community seed multipliers. Thus, this study contributes to the literature by conducting an economic feasibility analysis that includes all actors in the bean value chain and estimates additional investments attracted from public and private stakeholders. We further identified gains or losses on account of the externalities generated through different value chain actors. We find positive net present values (NPV) and a benefit–cost ratio (BCR) greater than one. This implies that the economic benefits of the bean value chain improvement program in the two countries are larger than their costs. Farmers and traders are the main beneficiaries, receiving 99% and 65% of the net economic benefits generated in the bean value chain in Burundi and Zimbabwe, respectively. Finally, we find the intervention sustainable and resilient against economic shocks, making it worth replicating in other countries in sub‐Sahara Africa and beyond. Pragmatic and policy options are recommended to inform future interventions of a similar nature.

Common beans (Phaseolus vulgaris L.) are a cornerstone of global nutrition, offering a sustainable source of protein, micronutrients, and bioactive compounds. This review synthesizes current research on critical consumer traits—seed coat darkening, cooking time, protein, and mineral content—highlighting their genetic, biochemical, and environmental determinants. Seed coat darkening, driven by proanthocyanidin oxidation and regulated by genes like J, sd, and Psd, significantly impacts marketability, while cooking time variations (19–271 min across genotypes) influence regional preferences and nutritional outcomes. Biofortification and low-phytic acid (lpa) breeding strategies enhance mineral bioavailability, addressing deficiencies in Sub-Saharan Africa and South Asia. Regional disparities in consumer preferences, such as the demand for fast-cooking yellow beans in East Africa, underscore the need for tailored breeding programs. Climate change poses challenges to yield and nutrient retention, necessitating climate-resilient varieties. This review proposes integrating genomics, marker-assisted selection, and postharvest innovations, for developing beans that align with consumer needs, cultural practices, and sustainability goals. This is the first synthesis linking seed coat biochemistry to regional preferences.

Common beans ( Phaseolus vulgaris L.) are a major source of protein and energy in sub-Saharan Africa, but their long cooking time (CKT) imposes social, economic, environmental and health burdens. This study aimed to accelerate genetic gain for shorter CKT while maintaining or improving other seed traits such as seed iron (Fe) and zinc (Zn) content, water absorption capacity (WAC) and 100-seed weight (SW100) across rapid cycles of early-generation genomic selection. Two related founder populations were selected from the African bean panel and intercrossed in 2020 (population A) and 2021 (population B), followed by rapid two-year cycles of augmented S 0 -derived family selection. Best linear unbiased predictions (BLUPs) of breeding values were obtained from pedigree, genomic and single-step (combined pedigree and genomic) multivariate linear mixed model analysis across two cycles. Shorter CKT was correlated with higher WAC but lower Fe and Zn. Realised genetic gain from cycle 1 to cycle 2 was high for CKT (average -8.0 min y -1 ) and WAC (average +7.7% y -1 ), but was accompanied by small decreases in Fe, Zn and SW100. Genomic and single-step models resulted in high accuracy of BLUPs and moderate predictive ability across breeding cycles. The predicted genomic BLUPs for CKT in cycle 2B S 0 seedlings were strongly correlated by rank with their realised genomic BLUPs in S 0 -derived self bulks one year later, especially in a leave-one-trait-out approach in single-step multivariate genomic analysis. Indirect selection in S 0 progeny plants based on correlated and easy-to-measure traits may increase the rate of genetic gain in all traits.

Seed systems in sub-Saharan Africa face constant challenges such as limited access to quality seeds and low varietal turnover. Despite numerous efforts aimed at formalizing seed markets, informal seed systems still dominate with 97% of smallholder farmers sourcing seeds of sorghum, common beans and groundnuts through farm-saved seed and local grain markets. Traders are deeply embedded in these local markets and are better positioned in shaping the seed demand, particularly among smallholders who buy grains as seeds from informal outlets. However, in most cases traders remain disconnected from formal breeding and seed dissemination efforts, subsequently leaving a gap between the development of improved varieties and their adoption by farmers. This scenario perpetuates the use of old varieties that are well known to traders, limiting potential benefits from genetic gains. In this study, we examine the factors that could influence traders’ decisions to sell grains of improved varieties. Data from a structured survey of 976 traders in Tanzania is used. We find that traders with higher financial capacity, stable market access, and those having strong relationships with farmers through credit provision are more likely to sell grains of improved varieties. Similarly, we find positive associations with switching to improved varieties among traders facing business challenges, accessing information through channels other than social media, and traders selling grains as seeds at sowing. In contrast, traders engaged inthe sale of highly demanded varieties are less likely to switch to new and improved varieties. Therefore, to spur the uptake of improved varieties, strengthening trader-farmer linkages, integrating traders into structured procurement systems, and enhancing trader involvement in participatory variety selection to refine existing and preferred varieties without changing them altogether are recommended. Additionally, there is need to strengthen business modeling programs to make grain traders’ businesses bankable, expand information sharing and facilitate access to credit enabling them to adequately offer technical support to thefarmers they source grains from.

Access to and utilization of quality seeds have been significant challenges facing Tanzania's agricultural sector, especially for open-pollinated crops such as common beans, sorghum, and groundnuts. Marketplace traders purchase grains for sale from farmers who often rely on traditional varieties, which may have lost their effectiveness in combating emerging challenges such as pests, diseases, climate change, and variability. Despite the availability of improved climate-resilient varieties, limited promotional efforts have been made to increase their adoption among marketplace traders, who are mainly women. Moreover, the current promotion and awareness-creation efforts by public and private partners often target smallholder farmers, with limited success in increasing adoption and replacing old varieties. This study explored the preferred approaches by marketplace traders for receiving information about newly released climate-resilient varieties to enable them to switch to selling grains of new climate-resilient varieties. Quantitative data were collected from 657 marketplace traders (372 women and 285 men), and qualitative data were collected from 180 marketplace traders across rural and urban markets, with women comprising 58% of them. Content and ethnographic methods were employed to analyze the qualitative data, while descriptive analysis and a multivariate probit model (MVP) were used to analyze the quantitative data. The findings show that marketplace traders have limited information about the existence of the new climate-resilient varieties but are motivated to receive information about the new climate-resilient varieties due to the associated supply, quality, and yield advantages. Local radio stations, in-person meetings, posters placed in the local markets, and WhatsApp groups are preferred channels for sharing information about new climate-resilient varieties with marketplace traders and some farmers. Due to low smartphone ownership, female marketplace traders preferred phone calls, text messages, local radio, and in-person meetings to access various types of information. A single approach is not a one-size-fits-all solution; it may be effective in some contexts but not in others. Therefore, prioritizing a set of effective approaches that women prefer for sharing information about climate-resilient varieties would be more likely to achieve the intended adoption impacts.

Limited climate information on weather patterns and adaptable varieties hinders decision-making and lowers productivity under climate change. Social media is vital on facilitating fast information access and dialog. This comparative study identifies observed climate changes, utilized adaptation measures, and social media usage patterns and its potential to deliver climate information to farmers in Tanzania. Data from 315 households were collected through semi-structured interviews in four regions across Northern and Southern Tanzania. Secondary data included 2 years of WhatsApp records and 30 years of NASA Power climate data to validate survey responses. Survey and WhatsApp data were analyzed using R statistical packages, while climate data were processed in ESRI ArcGIS software. Increased rainfall (100%) was identified as the most significant climate challenge over the past decade, yet 57% of farmers had taken no adaptation measures due to lack of knowledge. Farmers (18.4%) are connected to social media, and 9.5% (16.7% women) access climate information through the platforms. Despite low use, particularly among women, its potential is growing, with 68% of farmers trusting and utilizing the information. WhatsApp (67%) is the most widely used channel, and seed-related topics dominate discussions, though only 10% access information on which variety to plant. Best engagement times are 19:00–20:00 and the off-season. Location and education significantly influence adoption of climate information and social media use. The study emphasizes enhancing education on social media use and leveraging multiple channels to reach farmers across diverse geographies and socio-economic groups.

BackgroundCommon bean breeders strive to deliver farmer- and consumer-preferred varieties that are well-adapted to distinct production environments, changing markets and end uses. However, there is information gap on the key traits that customers prefer and are willing to pay for. This paper examined the preferences and willingness to pay for reduced cooking time and other selected traits in the Ugandan bean markets using a choice experiment data elicited from 1152 urban and rural bean consuming households. A latent class model was used to assess preferences and the willingness to pay for reduced cooking time.ResultsResults indicated that taste, cooking time, bean swelling on cooking, and grain color were the preferred attributes in decreasing order among non-bean-producers. About 72% of the urban consumers were willing to pay 41 shillings, 53 shillings and 42 shillings above prices for reduction in cooking time from 120 (status quo) to 90, 75, and 60 min, respectively. For consumers who also grow their beans for food and surplus for sale, reduced cooking time is important but not as much as yield and climate resilience. The study identified four distinct customer segments-two among bean-producing households and two among non-bean-producing households. Gender, education, level of altruism/openness to change, household economic status, and price sensitivity were the major factors influencing segment membership.ConclusionsThe study findings demonstrated that breeding to reduce cooking time will generate a significant social savings in terms of less cooking fuel, water and time, but cooking time ought to be considered alongside other attributes preferred by consumers and farmers to succeed. Results also suggest that women urban consumers attach more importance to higher levels of intrinsic traits (non-visible but experienced by consumers) compared to men-thus promotional campaigns popularizing new varieties should target women to stimulate demand.

Anthracnose caused by Colletotrichum lindemuthianum is the major common bean disease worldwide causing complete yield loss under favourable disease conditions. This study aimed to determine phenotypic traits associated with anthracnose resistance for future use in breeding programmes. Twenty-two common bean varieties (CBVs) were selected basing on susceptibility to anthracnose, advanced breeding lines, improved variety resembling advanced breeding lines and the farmer variety widely grown in Tanzania. Selected varieties were planted in anthracnose hotspot fields and the same CBVs were planted in a screen house to validate resistance to anthracnose. Anthracnose infection score, leaf length, leaf width, length of fifth internode, length of petiole, plant vigour, canopy height and canopy width were recorded. Data on number of plants emerging; days to flowering; days to maturity; plant stands at harvest; and grain yield were also collected and analysed using R software. Phenotypic traits evaluated differed significantly among genotypes, environment and genotype by environment interaction. Seventy-five percent of phenotypic traits evaluated were positively correlated to anthracnose resistance.Highly-strong correlations to anthracnose were observed on number of days to maturity, plant stands at harvest, plant vigour and grain yield. Leaf length, leaf width, length of fifth internode, length of petiole and number of stands emerging were strongly correlated to anthracnose resistance. Additive main effects and multiplicative interaction analysis (AMMI) revealed highest contribution of environment on anthracnose infection-58.9% and grain yield −84.9% compared to genotype effects on anthracnose infection −32.7% and grain yield-15.7%. Based on these results, four traits – plant vigour, number of days to maturity, number of plant stands at harvest and grain yield – are recommended for selecting anthracnose-resistant varieties. NUA 48, NUA 64 and RWR 2154 were superior varieties, resistant to anthracnose and high yielding, while Sweet Violet and VTT 923-23-10 were most stable varieties across environments. Further on-farm research is suggested to assess their performance and identify traits preferred by farmers.

The development of high-yielding, resilient cultivars is the primary goal of many crop breeding programmes, but the uptake of these new cultivars is persistently low in low-income countries. We discuss constraints related to the adoption of crop cultivars and stress the importance of participatory approaches in building trust and promoting the adoption of new technologies.

The analysis of the differential impacts of multiple improved technologies has largely accounted for selective adoption, considering either the full application of a bundle or its individual components. The impacts of adopting agricultural technology bundles on household welfare are less understood when considering a partial adoption of either the entire bundle or its individual components on a portion of crop area. We assess simultaneous adoption and the impacts of multiple improved technologies promoted as a bundle and recommended for legume intensification systems for smallholder farmers in Ethiopia. We use DNA fingerprinting data to precisely identify our key treatment—“adoption of improved bean varieties”—in this study. Using an endogenous multivariate treatment effects model, we found significant positive impacts of adopting bundled interventions on agricultural incomes and household food security but vulnerability to food insecurity persists for many households. We find that growing improved varieties with fertilizers increased household agricultural revenue, allowing for more legume consumption and enhancing their likelihood of achieving adequate food consumption and food security outcomes; however, the vulnerability to food insecurity of the adopters remains high due to pre-existing resource degradation issues. Given the similarity in production contexts in Sub-Saharan Africa, our results provide perspective for similar development interventions. We use the results of our analysis to discuss potential policy implications and programs to support technological intensification among smallholder farmers.