IITA Journal Articles

Permanent URI for this collectionhttps://hdl.handle.net/10568/68619

Browse

Now showing 1 - 20 of 5384

Unlocking the power of gene banks: diversity in base growth temperature provides opportunities for climate-smart agriculture
(Journal Article, 2025-01) Gambart, C.; Van Wesemael, J.; Swennen, R.; Tardieu, F.; Carpentier, S.
Implementation of context-specific solutions, including cultivation of varieties adapted to current and future climatic conditions, have been found to be effective in establishing resilient, climate-smart agricultural systems. Gene banks play a pivotal role in this. However, a large fraction of the collections remains neither genotyped nor phenotyped. Hypothesizing that significant genotypic diversity in Musa temperature responses exists, this study aimed to assess the diversity in the world's largest banana gene bank in terms of base temperature (Tbase) and to evaluate its impact on plant performance in the East African highlands during a projected climate scenario. One hundred and sixteen gene bank accessions were evaluated in the BananaTainer, a tailor-made high throughput phenotyping installation. Plant growth was quantified in response to temperature and genotype-specific Tbase were modelled. Growth responses of two genotypes were validated under greenhouse conditions, and gas exchange capacity measurements were made. The model confirmed genotype-specific Tbase, with 30% of the accessions showing a Tbase below the reference of 14°C. The Mutika/Lujugira subgroup, endemic to the East African highlands, appeared to display a low Tbase, although within subgroup diversity was revealed. Greenhouse validation further showed low temperature sensitivity/tolerance to be related to the photosynthetic capacity. This study, therefore, significantly advances the debate of within species diversity in temperature growth responses, while at the same time unlocking the power of gene banks. Moreover, with this case study on banana, we provide a high throughput method to reveal the existing genotypic diversity in temperature responses, paving the way for future research to establish climate-smart varieties.
Multifunctional coreid bug pheromones for efficient bioprotection against legume pests and enhanced food productivity
(Journal Article, 2024) Kpongbe, H.; Khamis, F.; Cheseto, X.; Kirwa, H.; Tamo, M.; Torto, B.
In Africa, food legumes such as cowpeas and beans constitute important sources of proteins for millions of rural and urban populations. However, attacks by multiple pest species can reduce yields by up to 80%. Small-holder farmers protect their crops against pests using conventional insecticides, thereby contributing to insecticide resistance and jeopardizing food safety. To date, no alternative sustainable practices are available to reduce insecticide use in the management of legume pests. This study aimed to provide a sustainable alternative to insecticide use based on semiochemicals to manage multiple legume pest species and enhance food productivity.
Prediction of acceptable colour of cooking bananas (matooke) using instrumental and sensory measurements
(Journal Article, 2024-05) Khakasa, E.; Muyanja, C.; Mugabi, R.; Babirye, M.P.; Namuddu, M.G.; Mukasa, Y.; Namanya, P.; Arinaitwe, I.K.; Uwimana, B.; Tumuhimbise, R.; Nowakunda, K.
The colour of cooking bananas (Matooke) is a critical attribute for consumer acceptance and the uptake of newly developed hybrids. The objective of this study was to evaluate the potential of instrumentation to predict consumer-acceptable matooke colour. Instrumental and sensory measurements were used to assess the colour of twenty-three matooke cultivars. A Konica Minolta chroma metre, CR-400 was used to measure colour intensity of both the raw and cooked matooke pulp in terms of lightness (L*), greenness (a*), and yellowness (b*). Sensory evaluation was performed by 12 trained panellists at the Food Biosciences Laboratories, NARL-Kawanda to establish the sensory quality of the matooke. Correlations between instrumental and sensory parameters were performed using XLSTAT. Partial Least Square regression analysis (PLS-R) was used to assess the strength of the relationships between the instrumental and sensory attributes. Pearson’s correlation revealed that the instrumental yellowness (b*) of the raw pulp showed a positive moderate correlation with the instrumental yellowness (b*) of the cooked matooke (r = 0.56). Similarly, positive correlations were observed between instrumental yellowness (b*) and homogeneity of the yellowness (r = 0.50). Partial Least Square regression analyses showed moderate predictive models for preferred colour, R2=0.50, and overall liking, R2=0.53. PCA results showed that instrumental measurements can be used to select matooke with acceptable colour. Four hybrids; NAROBAN 4, M30, NARITA14, and NARITA 4 had similar colour attributes as the landraces in terms of both instrumental and sensory yellowness. Overall, the results showed possible predictability of consumer acceptable colour of matooke which suggests that instrumental measurements can be used to predict the consumer-acceptable matooke colour thus a tool for selecting hybrids with acceptable colour.
Exploring the genetic resources of yam in the Democratic Republic of Congo: implications for breeding
(Journal Article, 2024) Adejumobi, I.; Adewumi, A.S.; Ouattara, F.; Olatunde, E.; Adheka, J.; Onautshu, D.; Kayondo, S.I.; Alaba, O.; Mushoriwa, H.; Agre, P.A.
Introduction: Landrace accession of yam species in the Democratic Republic of Congo (DRC) represents a valuable genetic resource for yam breeding programs. These accessions possess traits such as stress resilience and desirable food quality attributes that can be introduced into modern yam varieties. By analyzing the genetic diversity, identifying quantitative trait loci (QTLs) linked to key traits, and the genetic merits of these landraces, we can identify promising genetic markers for breeding programs aimed at improving yam production in DRC. Materials and methods: We analyzed 181 yam accessions from the Democratic Republic of Congo (DRC), representing six species commonly cultivated by farmers and their wild relatives. These accessions were genotyped using 10,621 DArTseq SNP markers and characterized for key productivity and food quality traits. Results and discussion: Population structure analysis revealed six distinct genetic groups within the yam accessions. Genome-wide association studies (GWAS) identified 14 SNP markers associated with five key traits, suggesting the accessions’ potential as a valuable genetic resource. Further dissection of their genetic merits in yam breeding using the Genomic Prediction of Cross Performance (GPCP) allowed the identification of several accessions with high crossing merit for multiple traits. Genomic Prediction of Cross Performance (GPCP) identified 20 accessions with high crossing merit (>2). Conclusions: These accessions demonstrate favorable genetic combinations for multiple traits, making them promising progenitors for developing segregating populations with improved characteristics. These findings highlight the potential of these accessions to contribute to genetic improvement in yam breeding programs in the DRC, focusing on traits such as productivity and food quality.
Signaling quality in informal markets. Evidence from an experimental auction in the Sahel
(Journal Article, 2025-01) Ricker-Gilbert, J.; Moussa, B.; Abdoulaye, T.
This study estimates the extent to which rural consumers in sub-Saharan Africa value quality signals about their food. We tested this by implementing an incentive-compatible Becker-Degroot Marschak auction among consumers in Niger and Northern Nigeria to estimate their willingness to pay (WTP) for cowpea (blackeyed pea) that was stored and sold in an improved grain storage bag that signaled unobservable quality in the form of insecticide-free grain. The improved bag had two inner layers of high-density plastic that created an airtight seal around the grain stored in it. The seal killed insects through suffocation rather than insecticide. The bag also had a branded label from its manufacturer on its outer layer to help distinguish it from a generic single-layer, woven storage bag. We estimated the size of the price differential (premium) that the average consumer placed on unobservable grain quality, as measured through the WTP premium for grain sold in the improved bag with a label. We also estimated the effect that consumers’ previous awareness of the improved bag had on their valuation of observable and unobservable quality. Our results indicated that on average consumers in Niger were willing to pay a 10% premium for cowpea stored and sold in the improved storage bag compared to cowpea of the same observable quality that was sold in a generic woven bag. The same unobservable quality premium was 17% in Nigeria. The results from this study provide evidence that there may be a latent demand for quality proxied by food safety among limited resource people in sub-Saharan Africa and that improved products with branded labels can potentially provide a quality signal to the market.
Exploring farmer’s assessment of soil quality and root yield in cassava-based cropping systems
(Journal Article, 2024) Mesele, S.A.; Soremi, P.S.; Adigun, J.K.
Farmers’ knowledge of soil quality and yield assessment were evaluated among cassava farmers in southwestern Nigeria. Data were collected on farmers’ demography, farming experience, criteria for selecting a site for cassava cultivation and preferences for those criteria, farmers’ methods of yield prediction and how it compares with the scientific approach, farmers’ agronomic knowledge and how it relates to the realities of climate change and soil fertility decline. The modal age class of the farmers is 45–55 years, and most of the farmers are male. The results show that farmers use a combination of soil and vegetation-based criteria to assess soil quality from which the decision to cultivate a given land is made. Among the soil-based criteria, soil drainage, colour, and depth rank the most and most used. Most of the farmers assessed yield before harvesting through green healthy leaves (25 %), large and shiny stems (25 %) and soil cracks (50 %). The predicted and measured cassava yields on farmer-managed farms were comparable, with an R2 of 0.63, although farmers overestimated the cassava root yield. There is a unanimous consensus among farmers that yield has declined in the last decade, with a mean of 36 %. The main cause of yield decline was attributed to declining rainfall and poor soils. Our study concluded that farmers have a good understanding of soil health and cassava agronomy through a process of trial and error and ingenuity as farmers’ local indices were consistent with conventional soil health indicators. It was suggested that, by recognising and incorporating traditional methods used by farmers to assess soil quality, we could enhance soil management strategies and raise productivity at the farm level.
The challenge of industrialization of a nature-based solution that allows farmers to produce aflatoxin-safe crops in various African countries
(Journal Article, 2024) Kaptoge, L.; Ortega-Beltran, A.; Atehnkeng, J.; Konlambigue, M.; Kamau, J.W.; Bandyopadhyay, R.
In sub-Saharan Africa (SSA), many crops are contaminated by Aspergillus section Flavi fungi with highly toxic, carcinogenic aflatoxins. This contamination has severe negative impacts on health, trade, income, and development sectors, hindering progress toward various objectives of most Sustainable Development Goals (SDGs), including SDG 2 – Zero Hunger and SDG 3 – Good Health and Wellbeing. Farmers, industries, and governments need sound aflatoxin management strategies to effectively limit aflatoxin contamination throughout the crop value chain. One effective technology is biocontrol using native atoxigenic isolates of A. flavus coated on a carrier that is applied on growing crops. Atoxigenic A. flavus competitively displaces aflatoxin producers in the field, and this form of bioprotection results in reduced aflatoxin in crops. Over 15 years ago, field tests in Nigeria using a manually manufactured biocontrol product showed promising results. However, it became evident that scaling up the manufacturing process was essential to make this bioprotectant widely accessible to millions of farmers and achieve tangible impact in the context of sustainable food systems. The objective of this paper is to document the evolution of biocontrol manufacturing from small-scale, lab-based production to industrial manufacturing at different scales. The improvements in product formulation, and manufacturing processes and design are highlighted to better address “fit-to-scale” product demand in different countries. Industrializing the manufacturing process coupled with incentivization, commercialization strategies, and effective partnerships has allowed the manufacturing of thousands of tons of biocontrol products. This has enabled production of over a million tons of aflatoxin-safe maize, groundnut, and sorghum, contributing to enhanced food safety and security in several countries in SSA. The key lesson learnt is that for any input-based technology to mitigate aflatoxin (or any food safety issue), their large-scale manufacturing and commercialization is crucial for achieving tangible results. Only widespread adoption of any technology can address the great challenge posed by aflatoxins, a critical step toward meeting several SDGs. The urgency to combat aflatoxin contamination is increasing as its impacts are intensifying in several regions across the globe.
Mitigation of aflatoxin contamination of maize, groundnut, and sorghum by commercial biocontrol products in farmers’ fields across Burkina Faso, Mali, Niger, and Togo
(Journal Article, 2024) Bonkoungou, S.; Dagno, K.; Basso, A.; Ekanao, T.; Atehnkeng, J.; Agbetiameh, D.; Neya, A.; Toure, M.; Tiendrebeogo, A.; Konate, M.; Outani, B.; Konlambigue, M.; Callicott, K.; Cotty, P.; Dieng, I.; Falade, T.D.O.; Bandyopadhyay, R.; Ortega-Beltran, A.
Background Aflatoxin contamination by Aspergillus section Flavi fungi poses a significant threat to food security and public health in sub-Saharan Africa (SSA). Maize, groundnut, and sorghum are staple crops frequently contaminated with aflatoxins, sometimes at dangerous levels. Despite its detrimental effects, many farmers in SSA lack access to effective tools for mitigating aflatoxin contamination. Biocontrol based on atoxigenic isolates of A. flavus is an effective tool to limit aflatoxin contamination. Methods The development, testing, registration, and commercial use of the aflatoxin biocontrol product Aflasafe BF01 for use in Burkina Faso is described. In addition, the deployment of the biocontrol technology across Mali, Niger, and Togo is documented, and for the first time, the use of aflatoxin biocontrol in sorghum is reported. Results In all four countries, treated crops had significantly (P < 0.05) less aflatoxins than crops from untreated fields. Most treated crops met the stringent tolerance threshold for human consumption, 4 ppb total aflatoxin. Using native atoxigenic isolates of A. flavus and employing a multi-disciplinary approach, aflatoxin biocontrol products have demonstrated significant success in reducing aflatoxin levels in treated crops compared to untreated ones. Conclusions This multi-year, multi-funded source study underscores the effectiveness of biocontrol strategies in mitigating aflatoxin contamination at scale, offering a regional approach for sustainable management in West Africa and potentially unlocking significant health and economic benefits for the region.
Remotely sensed spectral indicators of bird taxonomic, functional and phylogenetic diversity across Afrotropical urban and non-urban habitats
(Journal Article, 2025-01) Awoyemi, A.G.; Alabi, T.R.; Ibanez-Alamo, J.D.
Urban areas are quickly expanding around the world, promoting deep changes in biodiversity. However, certain biogeographic realms, like the Afrotropics, are clearly understudied despite urbanization overlapping with their biodiversity hotspots. A commonly highlighted reason for the lack of information from the Afrotropics has been the logistical problem associated with data collection in the field. Recent advances in satellite remote sensing imagery offer an excellent opportunity to revert this situation, enhancing the understanding of urban impacts on biodiversity. The Normalized Difference Vegetation Index (NDVI) is the most commonly used remotely sensed spectral index (hereafter: indicator) despite several studies showing its limitations and advocating for the use of alternative indicators. Thus, this study identifies the best indicators of bird taxonomic, functional, and phylogenetic diversity in Afrotropical urban and non-urban areas. To do so, we sampled birds at 400 points equally distributed across eight Nigerian areas, two vegetation zones (rainforest vs savannah), and two habitats (urban vs non-urban), and extracted 29 indicators (mean and SD) at 50-m radius of each point (exact area of bird censuses). Random Forest Regressions and Generalized Linear Mixed Effect Models were used to identify the topmost ranked indicator of each avian diversity component, and its variation between urban and non-urban areas. The Modified Chlorophyll Absorption Ratio Index (MCARI) was the best indicator of taxonomic and phylogenetic diversity, while the Normalized Difference Water Index II (NDWI2) and Soil Adjusted Total Vegetation Index (SATVI) got the most support for functional diversity and phylogenetic divergence, respectively. In most cases, NDVI ranks very low (occupying the 25th percentile), not supporting its use for monitoring avian diversity in the Afrotropics. MCARI and NDWI2 showed different associations with taxonomic and functional diversity depending on the habitat, highlighting the need for considering urban areas differently while using these indicators. Our study provides useful tools to remotely monitor Afrotropical avian diversity, particularly in expansive, inaccessible or insecure areas, which could also be more cost-effective.
Development of standard operating protocol for measurement of cassava root mealiness
(Journal Article, 2024) Osunbade, A.O.; Alamu, E.O.; Awoyale, W.; Adesokan, M.; Akinwande, B.; Adejuyitan, A.; Maziya-Dixon, B.
One of the major attributes of boiled cassava roots is its ability to soften within a short period, otherwise known as mealiness. This study aimed to establish and validate standard operating procedures for assessing the mealiness of boiled cassava roots. Twenty cassava genotypes, including landrace and improved varieties, were selected for the protocol development, with an additional ten genotypes used for validation. Following cooking, the cassava roots were evaluated for hardness and work done in extrusion using a texturometer equipped with a five-blade Ottawa cell probe. The same samples were assessed for sensory texture analysis using trained panelists for parameters such as softness and chewiness. Pearson's correlation analysis revealed significant positive correlations (p < 0.01) between sensory softness and instrumental texture measurements, as well as between softness and cooking time (p < 0.01, r = 0.94), and between chewiness and cooking time (p < 0.05, r = 0.81). Validation results confirmed significant correlations (p < 0.01) between cooking time, sensory softness, and chewiness. These findings suggest that cooking time can serve as a reliable indicator, closely associated with sensory attributes, in determining the mealiness of boiled cassava roots. This approach offers a practical, mid-throughput method for assessing cassava root mealiness, with implications for breeding improved varieties, farmers adoption, and consumer acceptance.
Exploring the West African forest island phenomenon: scientific insights gained, successes achieved and capacities strengthened
(Journal Article, 2024) Logah, V.; Azeez, J.; Compaore, H.; Mesele, S.A.; Ocansey, C.M.; Bougma, A.; Tetteh, E.N.; Veenendaal, E.M.; Lloyd, J.
Anthropogenic activities around local villages in mesic savanna landscapes of West Africa have resulted in soil improvement and forest establishment outside their climatic zones. Such unique ‘forest islands’ have been reported to provide ecosystem services including biodiversity conservation. However, the science underpinning their formations is limitedly studied. In 2015 and with funding support from the Royal Society-DFID (now FCDO), we set out to investigate the biogeochemistry of the forest islands in comparison with adjacent natural savanna and farmlands across 11 locations in Burkina Faso, Ghana and Nigeria. Our results showed that the forest islands do not differ significantly from the adjoining ecosystems in soil mineralogy implying that their formation was anthropogenically driven. We observed greater soil organic carbon and nutrient distributions in the forest islands, which also had more stable macro (>500 μm) and meso-aggregates (500–250 μm) than the adjoining agricultural lands. We found that soil micro-aggregate (250–53 μm) stability was climate (precipitation) driven in the West African ecosystems while meso- and macro-aggregate stability was land-use driven. In one of the unique forest islands we studied in the Mole National Park of Ghana, we found its mineral-associated organic carbon over 40% greater than the adjoining natural savanna with potential implications for the achievement of the global initiative of the ‘4p1000’ in West Africa. We conclude that the North–South–South research collaboration has established clearly, the science underlying the age-long West African forest island phenomenon and has, among many successes, led to capacity building of young scientists driving cutting-edge research in climate change adaptation and food systems transformation in the sub-region.
Organic carbon and nutrient enrichment in clay-rich calcareous soils in self-regenerating fallows in humid tropical agroecology
(Journal Article, 2024) Mesele, S.A.; Soremi, P.S.; Ayamba, B.E.; Aderolu, J.; Olayiwola, V.A.
Self-regenerating fallows are areas left to regenerate naturally after agricultural use and are typically characterized by diverse plant species and minimal human intervention. To measure the efficiency of this natural fallow system, we evaluated soil organic carbon (SOC) and nutrient concentrations vis-à-vis the fallow duration. The study site was located in the Onigbedu community, Ogun State, Nigeria, with large commercial limestone deposits. Mining and agriculture are the main land use types. The study was oriented on 100 hectares of land previously cultivated at different times and left to fallow. The fallow duration ranged between less than 3 years and more than 20 years. At the end of this study, it was observed that the soils are within a large group of calcareous soils. SOC ranged from 15 to 26 mg/g, available phosphorus from 3.0 to 6.0 mg/kg, total nitrogen from 0.5–2.0 mg/g, effective cation exchange capacity (ECEC) from 2.0–24.0 cmol(+)/kg, calcium from 2.0–20 cmol(+)/kg, Mg from 1.0–2.0 cmol(+)/kg, 0.1–0.4 cmol(+)/kg, manganese from 19 to 80 mg/kg, and zinc from 1.5–2.0 mg/kg in increasing order of fallow duration. Soil nutrients and SOC improved consistently with increasing fallow periods. While fallow duration influenced soil nutrient build-up, other management practices and environmental factors also play significant roles. Farmers can enhance soil fertility and nutrient levels by optimizing fallow durations and using efficient soil management practices, leading to sustainable agriculture and improved crop yields.
Edaphic factors modulating phosphorus availability in lowland rice systems, Nigeria
(Journal Article, 2024) Mesele, S.A.; Ajiboye, G.A.; Talbot, J.
The low rice production level in Africa is attributed to poor soil fertility despite the potential for rice cultivation in the inland valleys. This study was conducted to evaluate soil characteristics in some lowlands that have been continuously and intensively used for rice production for over two decades in southwestern Nigeria. Soil physical, chemical, and mineralogical properties, as well as phosphorus sorption characteristics, were assessed in soil samples collected from diagnostic horizons of profiles in six benchmark soils. The results show kaolinite, quartz, potassium(K)-feldspars, and mixed-layered smectite as the predominant minerals. The iron oxide fractions indicate that the soils are at varying degrees of development where the soils at the advanced stage of development are predominantly rich in kaolinite and quartz with a high concentration of total pedogenic iron oxide and generally low in soil fertility. Soil phosphorus buffering capacity is low and varies inversely with pH, confirming the deficiency of phosphorus at low pH. Short-range-order (SRO) iron (Fe) oxides show a strong affinity for phosphorus and this is stronger at lower soil horizons and mediated by some redoxomorphic reactions. The SRO iron oxide concentration has more influence on phosphorus retention in soils rather than the absolute concentration of iron oxides. The study concludes that SRO Fe oxides and soil pH are the major edaphic factors playing a prominent role in phosphorus retention and availability in the wetland soils rather than the clay minerals.
Toward marker-assisted selection in breeding for fusarium wilt tropical race-4 type resistant bananas
(Journal Article, 2024) Ferreira, C. F.; Chen, A.; Aitken, E. A. B.; Swennen, R.; Uwimana, B.; de Jesus Rocha, A.; da Silva Soares, J. M.; de Souza Ramos, A. P.; Amorim, E. P.
Fusarium wilt is a soil borne fungal disease that has devastated banana production in plantations around the world. Most Cavendish-type bananas are susceptible to strains of Fusarium oxysporum f. sp. cubense (Foc) belonging to the Subtropical Race 4 (STR4) and Tropical Race 4 (TR4). The wild banana diploid Musa acuminata ssp. malaccensis (AA, 2n = 22) carries resistance to Foc TR4. A previous study using segregating populations derived from M. acuminata ssp. malaccensis identified a quantitative trait locus (QTL) (12.9 cM) on the distal part of the long arm of chromosome 3, conferring resistance to both Foc TR4 and STR4. An SNP marker, based on the gene Macma4_03_g32560 of the reference genome ‘DH-Pahang’ v4, detected the segregation of resistance to Foc STR4 and TR4 at this locus. Using this marker, we assessed putative TR4 resistance sources in 123 accessions from the breeding program in Brazil, which houses one of the largest germplasm collections of Musa spp. in the world. The resistance marker allele was detected in a number of accessions, including improved diploids and commercial cultivars. Sequencing further confirmed the identity of the SNP at this locus. Results from the marker screening will assist in developing strategies for pre-breeding Foc TR4-resistant bananas. This study represents the first-ever report of marker-assisted screening in a comprehensive collection of banana accessions in South America. Accessions carrying the resistance marker allele will be validated in the field to confirm Foc TR4 resistance.
Fighting to thrive via plant growth regulators: green chemical strategies for drought stress tolerance
(Journal Article, 2024-11) Raza, A.; Bhardwaj, S.; Rahman, M.A.; Garcia-Caparros, P.; Copeland, R.G.; Charagh, S.; Rivero, R.M.; Gopalakrishnan, S.; Corpas, F.J.; Siddique, K.H.M.; Hu, Z.
As global climate change intensifies, the occurrence and severity of various abiotic stresses will significantly threaten plant health and productivity. Drought stress (DS) is a formidable obstacle, disrupting normal plant functions through specific morphological, physiological, biochemical, and molecular mechanisms. Understanding how plants navigate DS is paramount to mitigating its adverse effects. In response to DS, plants synthesize or accumulate various plant growth regulators (PGRs), including phytohormones, neurotransmitters, gasotransmitters, and polyamines, which present promising sustainable green chemical strategies to adapt or tolerate stress conditions. These PGRs orchestrate crucial plant structure and function adjustments, activating defense systems and modulating cellular-level responses, transcript levels, transcription factors, metabolic genes, and stress-responsive candidate proteins. However, the efficacy of these molecules in mitigating DS depends on the plant species, applied PGR dose, treatment type, duration of DS exposure, and growth stages. Thus, exploring the integrated impact of PGRs on enhancing plant fitness and DS tolerance is crucial for global food security and sustainable agriculture. This review investigates plant responses to DS, explains the potential of exogenously applied diverse PGRs, dissects the complex chemistry among PGRs, and sheds light on omics approaches for harnessing the molecular basis of DS tolerance. This updated review delivers comprehensive mechanistic insights for leveraging various PGRs to enhance overall plant fitness under DS conditions.
Keeping toxigenic Aspergillus section Flavi and aflatoxin contamination at bay by deploying atoxigenic-based biocontrol products during production of groundnut and maize in Mozambique
(Journal Article, 2024) Augusto, J.; Atehnkeng, J.; Ortega-Beltran, A.; Cotty, P.J.; Bandyopadhyay, R.
Aflatoxins, produced by aflatoxigenic Aspergillus section Flavi fungi, commonly occur in groundnut and maize grown in Mozambique and have long been associated with high prevalence of liver cancer, stunting, and restricted access to lucrative international markets. Effective aflatoxin control options in the country are limited and not adequately explored. Biocontrol products based on atoxigenic strains of A. flavus provide viable aflatoxin mitigation measures but require development for Mozambique. Four hundred and sixty-eight (468) and 558 groundnut and maize farmers, respectively, voluntarily evaluated the effectiveness of two biocontrol products (Aflasafe MWMZ01 and Aflasafe MZ02), each containing as active ingredients four distinct atoxigenic isolates of A. flavus belonging to native vegetative compatibility groups (VCGs), at preventing aflatoxin contamination and displacement of aflatoxigenic fungi for 2 years in various agro-ecologies. Most groundnut and maize treated with the biocontrol products were below maximum levels for food in the European Union (EU; 85%; p < 0.01) and the United States (US; 99%; p < 0.01). In contrast, most non-treated maize and groundnut (ranging from 38 to 70%; p = 0.05) were above the EU and US maximum allowable levels for food. Aflatoxin reductions ranged from 78 to 98% (p < 0.01) in treated groundnut, and from 61 to 93% (p < 0.01) in treated maize. Toxigenic fungi were almost completely displaced from soils and crops by the applied atoxigenic active ingredients. This study revealed that the atoxigenic based biocontrol technology is effective in Mozambique at displacing aflatoxigenic fungi and reducing aflatoxin accumulation in both groundnut and maize but a combination with other management tools is encouraged for better retention of crop quality along the value chain.
Mycotoxin concentrations in rice are affected by chalkiness, grain shape, processing type, and grain origin
(Journal Article, 2024) Tang, E.N.; Ndindeng, S.A.; Onaga, G.; Ortega-Beltran, A.; Falade, T.D.O.; Djouaka, R.F.; Frei, M.
Mycotoxins such as aflatoxins (AFs), fumonisins (FBs), zearalenone (ZEN), and deoxynivalenol (DON) pose a risk to public health due to their carcinogenic potency (AFs and FBs) and anti-nutritional effects. The hazards associated with mycotoxins are accentuated where food management practices, control, and regulatory systems from farm to plate are sub-optimal. Information on the frequency of these mycotoxins in rice commercialized in markets in sub-Sahara Africa (SSA) is limited. The current study examined AF concentrations in 527 rice samples collected from 54 markets in five SSA countries. Grain quality characteristics, processing methods, and origin of samples were contrasted with toxin levels. In total, 72% of the samples had detectable AFs levels (range = 3.0 to 89.8 μg/kg). Forty-seven percent (47%) of the samples had AFs above 4 μg/kg, the European Union maximum level (ML), and were evaluated for cooccurrence with FBs, ZEN, and DON. Total AFs and ZEN cooccurred in 40% of the samples, and 30% of the positive ZEN samples had concentrations above the ML of 75 μg/kg. Total AFs did not co-occur with FBs and DON. Multivariate analysis revealed that length-to-width ratio (p < 0.0001), mixed variety for width (p = 0.04), and chalkiness (p = 0.009) significantly influenced aflatoxin concentrations. Slender grains had higher AFs concentrations than bold and medium grains (p < 0.0001). Possible strategies to mitigate mycotoxin contamination in rice include improving grain quality traits and practicing proper drying and hermetic storage before and after milling. These findings provide valuable insights for both domestic and international actors in establishing and strengthening regulations and management systems to mitigate rice mycotoxin contamination.
Physico-chemical characterization of anopheles gambiae s.l. breeding sites and kdr mutations in urban areas of Cotonou and Natitingou, Benin
(Journal Article, 2024) Djegbe, I.; Hessou-Djossou, D.; Boukari, M. Y. G.; Nonfodji, O.; Tchigossou, G.; Djouaka, R. F.; Cornelie, S.; Akogbeto, M.; Djogbenou, S. L.; Chandre, F.
Background This study aimed to investigate the relationship between the physicochemical characteristics of An. gambiae s.s. and An. coluzzii breeding sites, the susceptibility profiles to commonly used insecticides in public health, and the underlying insecticide resistance mechanisms. Methods Anopheles breeding sites surveys were conducted in Cotonou and Natitingou in September 2020, January and August 2021. Physicochemical properties and bacterial loads were determined in individual breeding sites. The WHO susceptibility assays were carried out using the female of the emerging adult mosquitoes. Anopheles species were identified through PCR techniques. Kdr L1014F/S, N1575Y and G119S mutations were investigated using TaqMan genotyping assays. Results Molecular analysis showed that all mosquitoes analyzed in Cotonou were Anopheles coluzzii, while those of Natitingou were Anopheles gambiae s.s. Fecal coliforms were identified as playing a role in this distribution through their significant influence on the presence of An. coluzzii larvae. WHO susceptibility assay indicated a high level of resistance to deltamethrin in the two cities. The resistance levels to deltamethrin were higher in Cotonou (X2 = 31.689; DF = 1; P < 0.0001). There was a suspected resistance to bendiocarb in Cotonou, whereas the mosquito population in Natitingou was resistant. The kdr L1014F mutation was highly observed in both mosquito populations (frequence: 86–91%), while the Ace-1 mutation was found in a small proportion of mosquitoes. In Cotonou, salinity was the only recorded physicochemical parameter that significantly correlated with the resistance of Anopheles mosquitoes to deltamethrin (P < 0.05). In Natitingou, significant correlations were observed between the allelic frequencies of the kdr L1014F mutation and pH, conductivity, and TDS. Conclusion These results indicate a high level of pyrethroid resistance in the anopheles populations of both Cotonou and Natitingou. Moreover, this study report the involvement of abiotic factors influencing Anopheles susceptibility profile.
Awareness of aflatoxin and willingness to pay for aflasafe technology among maize farmers in Cibitoke, Makamba and Bujumbura provinces in Burundi
(Journal Article, 2024) Nduwimana, D.; Nwenjeri, G.; Bett, E.; Atehnkeng, J.
This study aimed to assess the awareness of aflatoxin among maize farmers in Burundi and their willingness to pay for Aflasafe technology, with a focus on the provinces of Bujumbura, Cibitoke, and Makamba.
Associations between urbanization and avian communities in the Afrotropics: evidence from taxonomic, functional and phylogenetic diversity
(Journal Article, 2024-10) Awoyemi, A.G.; Barshep, Y.; Manu, S.A.; Ibanez-Alamo, J.D.
Urbanization negatively affects biodiversity worldwide, with the rapidly urbanizing Afrotropical area being understudied. Furthermore, most previous studies investigating this topic focused on taxonomic diversity while recent findings have highlighted the need to incorporate complementary diversity metrics. Thus, this study investigated how urbanization affects bird taxonomic, functional, and phylogenetic diversity in Nigeria, a country with one of the fastest rates of urbanization in the world. We conducted bird censuses at 400 points organized across eight paired comparisons (urban vs non-urban habitats), vegetation zones (rainforest vs savannah), and seasons (dry vs wet). Of the total 237 bird species recorded, 65 % were never encountered in urban areas, suggesting the negative effect of urbanization that was also supported by our statistical analyses. Taxonomic diversity was significantly higher in non-urban than urban habitats. This contrasted with the result on functional and phylogenetic diversity, which was higher in the urban than non-urban habitat. These relationships were similar across seasons, but more intense in the rainforest, revealing that birds in this vegetation zone are more vulnerable to urbanization than their savannah counterparts. We also found that water cover significantly promoted all avian diversity metrics analyzed during the dry season independently of urbanization. In contrast, canopy and bush cover mediated the effects of urbanization on some diversity components (i.e., functional and phylogenetic diversity). Our results highlight the significance of incorporating spatiotemporal patterns in related studies and provide much needed information for city planners and other urban stakeholders in the Afrotropics.

Browse

Recent Submissions