Aflatoxin Contamination Of Maize Research Articles

Effects of Different Shelling Methods on Data Variability during Field Screening for Reduced Aflatoxin Contamination in Maize.

Non-genetic variation limits the identification of novel maize germplasm with genetic markers for reduced Aspergillus flavus infection and aflatoxin contamination. Aflatoxin measurements can vary substantially within fields containing the same germplasm following inoculation with A. flavus. While some variation is expected due to microenvironmental differences, components of field screening methodologies may also contribute to variability in collected data. Therefore, the objective of this study is to test the effects of three different shelling methods (whole ear (WE), ear end removal (EER), and inoculation site-surrounding (ISS)) to obtain bulk samples from maize on aflatoxin measurements. Five ears per row of three inbred lines and two hybrids were inoculated with A. flavus, then shelled using the three different methods, and aflatoxin was quantified. Overall, EER and ISS resulted in reduced coefficients of variance (CVs) in comparison to WE for both inbred and hybrid maize lines, with two exceptions. Susceptible B73 showed increased CVs with both EER and ISS compared to WE, and resistant Mp719's EER CVs marginally increased compared to WE. While WE is the standard practice for most breeding programs due to its technical simplicity, EER and ISS may allow for finely phenotyping parental lines for further breeding applications.

Evaluation of aflatoxin content in “Cheka” (traditional beverage in South-Western Ethiopia) and its major ingredient (maize)

BackgroundAflatoxin is a toxic cancerous fungal secondary metabolite produced by Aspergillus species. Consumption of aflatoxin-contaminated cereals and their products can cause several health-related effects including acute and chronic aflatoxicosis. This study aims to evaluate the total aflatoxin content in “Cheka” and its major ingredients using the Immuno-Affinity Column Clean-up technique by sensitive HPLC (High-Performance Liquid Chromatography) with fluorescence detection.MethodsThis study followed a completely randomized experimental design to evaluate the level of aflatoxin in traditionally brewed “Cheka” and its major ingredients (maize) by HPLC from November 2019 to June 2020. Traditionally brewed 6 “Cheka” beverages and 6 maize seed samples were collected randomly from Konso and transported to Bless Agri Food Laboratory in Addis Ababa for laboratory evaluation of aflatoxin in samples. The data were analyzed by SPSS version 25.ResultsIn the present study aflatoxin contamination was detected in all maize and “Cheka” samples. A mean total aflatoxin level of 6.78 ± 8.28 μg/kg and 10.76 ± 4.50 μg/kg were observed in maize and “Cheka” samples respectively. The maize taken from above-ground storage (“Gotera”) and underground storage (pitfall) showed a mean total aflatoxin level of 10.23 ± 10.12 μg/kg and 3.35 ± 5.79 μg/kg respectively. The samples taken from “Cheka” prepared from maize of above-ground storage (“Gotera”) and underground storage (pitfall) showed a mean total aflatoxin level of 11.34 ± 3.06 μg/kg and 10.19 ± 6.35 μg/kg respectively. Aflatoxin G family was not detected in both maize and “Cheka” samples while aflatoxin B1 and B2 contributed to the total aflatoxin level. AFB1 predominantly contributed to the contamination of all samples. Although there was no significant difference while comparing between mean total aflatoxin of any other sample types, a significant difference was observed for the AFB1 mean level of pitfall maize and their respective “Cheka” samples (P = 0.033).ConclusionThe mean level of AFB1 in pitfall maize differs from a respective “Cheka” sample. As most of the samples evaluated for aflatoxin contamination showed levels above healthy cut-off points of aflatoxin set by different authorities like the European Union, CODEX, and Ethiopian Standards Agency, there must be a protracted interventional approach to reduce aflatoxin contamination in maize and its products in the region.

Assessment the Level of Awareness of Aflatoxin Contaminations in Maize-Based Meals Among Boarding School Personnel

Tanzania is a tropical country that lies few degrees south of the equator The coast area includes regions such as Dar es Salaam and Coastal region which are hot and humid with cooling breezes of the Indian Ocean. Awareness of society is a crucial aspect of ensuring the safety and quality of food. One of the risk factors in food safety is the presence of aflatoxin in various foods such as cereals, and groundnuts. The aim of this study was to assess the levels of awareness of aflatoxin B1 contamination in maize and maize flour used for meals in boarding secondary schools. A total of 90 respondents from 30 schools from 7 districts of the two regions were interviewed. Semi-structured questionnaires were used to collect information and the survey showed that 74.4% of the respondents were aware of aflatoxin contamination. 85.6% of respondents know that aflatoxin is found in food and only 14.4% were not aware. 74.4% were capable of selecting the correct list of food that can be contaminated with aflatoxin while 11.1% selected the wrong list. 14.4% of the respondents were unable to select the list of foods that can be contaminated with aflatoxin. These results indicate that most of them are aware of the issue of aflatoxin contamination in maize and its products which is good for reducing aflatoxin contamination in food products and its effect. An effective and broad awareness program for the society including boarding school personnel and students on good management of food for prevention of aflatoxins contamination and its health effects is necessary, as maize and its products are the most consumed grain in the study area.

Assessment of mycotoxin contamination in Rwanda: A comparison of agro-ecological zones

Aflatoxin contamination of maize in Rwanda and underlying causes are poorly documented. This study aimed to address this gap where maize samples for aflatoxins analysis were collected from two different agro-ecological zones and the temperature and relative humidity conditions during the time preceding sample collection were monitored to determine the conditions conducive to this contamination. Maize was analysed for moisture content and aflatoxin contamination and the temperature and humidity data were used to estimate the saturation deficit of the ambient air as an indicator of risk of contamination, which is high when the saturation deficit is low. Results showed an average lower saturation deficit of 0.0018 kg H₂O kg−1 in the high-altitude Volcanic region compared to the 0.00095 kg H₂O kg−1 recorded in the lower altitude region of the Eastern Savannah. Given the high moisture content in most of the analysed samples, this meant that it is more challenging to dry maize to the safe storage moisture content in the Volcanic region compared to the Eastern Savannah. The mean aflatoxin contamination was 40.45 μg kg−1 in the Volcanic region significantly higher than 4.66 μg kg−1 in the Eastern Savannah. Aflatoxin G1 was predominant among the contaminated samples. Affordable drying technologies that use renewable sources of energy should be developed and made accessible to farmer cooperatives.

An integrated model for pre- and post-harvest aflatoxin contamination in maize

Aflatoxin contamination caused by colonization of maize by Aspergillus flavus continues to pose a major human and livestock health hazard in the food chain. Increasing attention has been focused on the development of models to predict risk and to identify effective intervention strategies. Most risk prediction models have focused on elucidating weather and site variables on the pre-harvest dynamics of A. flavus growth and aflatoxin production. However fungal growth and toxin accumulation continue to occur after harvest, especially in countries where storage conditions are limited by logistical and cost constraints. In this paper, building on previous work, we introduce and test an integrated meteorology-driven epidemiological model that covers the entire supply chain from planting to delivery. We parameterise the model using approximate Bayesian computation with monthly time-series data over six years for contamination levels of aflatoxin in daily shipments received from up to three sourcing regions at a high-volume maize processing plant in South Central India. The time series for aflatoxin levels from the parameterised model successfully replicated the overall profile, scale and variance of the historical aflatoxin datasets used for fitting and validation. We use the model to illustrate the dynamics of A. flavus growth and aflatoxin production during the pre- and post-harvest phases in different sourcing regions, in short-term predictions to inform decision making about sourcing supplies and to compare intervention strategies to reduce the risks of aflatoxin contamination.

Genetic Diversity of Aspergillus flavus on Maize in Guatemala.

Aflatoxin contamination of maize is a leading threat to health in Guatemala. This contamination is the result of infection from Aspergillus flavus and has been effectively reduced in other countries through application of nonaflatoxigenic, indigenous strains of A. flavus. We collected 82 maize samples from throughout Guatemala in two years and isolated 272 A. flavus from these samples, including 126 unique genotypes. We provide here a phenotypic and simple sequence repeat (SSR)-based genotypic description of these isolates, as well as an analysis of the diversity of this population. High levels of genetic diversity were observed with the nonaflatoxigenic isolates in this study, but this information contributes to the development of indigenous aflatoxin biocontrol products.

Physiological Response and Aflatoxin Contamination in Maize (Zea Mays L.) Grown Under Varying Water-Deficit Levels in a Semi-Arid Region

The present study explored the effects of water deficit levels at different growth stages of maize (Zea mays L.) cultivated in semi-arid conditions with regard to physiological responses and aflatoxin contamination. The physiological growth changes of maize hybrids were gauged for parameters viz. relative water content (RWC, %), root-shoot ratio (R/S), and specific leaf area (SLA). At the same time, the study used HELICA total Aflatoxin Assay for estimating aflatoxin contamination in the produced maize kernel. Results revealed the third level of water-deficit, which extended to the dent stage, led to lower RWC%, and higher (R/S), alongside lower (SLA). Although the aflatoxin level was estimated to be 18.5 ppb in the maize kernels (FDA limit = 20 ppb), it was apparent that cultivation in a semi-arid condition runs the risk of aflatoxin contamination, likely due to water shortage and high growing temperatures.

Risk mitigation of aflatoxin contamination in maize and its food and feed products in developing countries: a review

Food safety is key to a health population in the developing countries along the whole value. Maize and its products’ safety from aflatoxin is a concern taking into consideration that they are highly consumed in these countries as their staple food by individuals from different socio- economic levels and upbringings. It’s used to manufacture human foods which include maize flour, grits, porridge, beers among others and animal feeds where their consumption show health benefits such as provision of vitamin B-complex for skin, heart, brain, hair and improved digestion in humans. Aflatoxin exposure from maize products and feeds consumption have been so frequent in alarming rates leading to Aflatoxicosis which is a serious health risks to consumers and livestock, maize grain scarcity and global trade impact therefore nations have set strict threshold limits. Google Scholar database was used in the research of the literature articles that are recent and related to aflatoxin in maize grains. Great emphasis is based on maize grains and feeds’ safety from aflatoxins thus this review is focused on the aflatoxin in maize in terms of research on recent toxicity data, maize contamination impacts, mitigation measures research on safe methods that can’t lead to risks due to further contamination with harmful residuals and the future interventions from the literature that should be installed considering that maize is the main food in Sub- Saharan Africa. Therefore, available mitigations are applicable and hence the government relevant bodies are required to enforce strict measures on their application while enhancing a favorable environment to partners who would be available in installation of the future predicted measures.

Comprehensive meta-analysis of QTL and gene expression studies identify candidate genes associated with Aspergillus flavus resistance in maize.

Aflatoxin (AF) contamination, caused by Aspergillus flavus, compromises the food safety and marketability of commodities, such as maize, cotton, peanuts, and tree nuts. Multigenic inheritance of AF resistance impedes conventional introgression of resistance traits into high-yielding commercial maize varieties. Several AF resistance-associated quantitative trait loci (QTLs) and markers have been reported from multiple biparental mapping and genome-wide association studies (GWAS) in maize. However, QTLs with large confidence intervals (CI) explaining inconsistent phenotypic variance limit their use in marker-assisted selection. Meta-analysis of published QTLs can identify significant meta-QTLs (MQTLs) with a narrower CI for reliable identification of genes and linked markers for AF resistance. Using 276 out of 356 reported QTLs controlling resistance to A. flavus infection and AF contamination in maize, we identified 58 MQTLs on all 10 chromosomes with a 66.5% reduction in the average CI. Similarly, a meta-analysis of maize genes differentially expressed in response to (a)biotic stresses from the to-date published literature identified 591 genes putatively responding to only A. flavus infection, of which 14 were significantly differentially expressed (-1.0 ≤ Log2Fc ≥ 1.0; p ≤ 0.05). Eight MQTLs were validated by their colocalization with 14A. flavus resistance-associated SNPs identified from GWAS in maize. A total of 15 genes were physically close between the MQTL intervals and SNPs. Assessment of 12 MQTL-linked SSR markers identified three markers that could discriminate 14 and eight cultivars with resistance and susceptible responses, respectively. A comprehensive meta-analysis of QTLs and differentially expressed genes led to the identification of genes and makers for their potential application in marker-assisted breeding of A. flavus-resistant maize varieties.

Targeting the Aspergillus flavus p2c gene through host-induced gene silencing reduces A. flavus infection and aflatoxin contamination in transgenic maize.

Aspergillus flavus is an opportunistic fungal pathogen that infects maize and produces aflatoxins. Using biocontrol or developing resistant cultivars to reduce aflatoxin contamination has only achieved limited success. Here, the A. flavus polygalacturonase gene (p2c) was targeted for suppression through host-induced gene silencing (HIGS) to reduce aflatoxin contamination in maize. An RNAi vector carrying a portion of the p2c gene was constructed and transformed into maize B104. Thirteen out of fifteen independent transformation events were confirmed to contain p2c. The T2 generation kernels containing the p2c transgene had less aflatoxin than those without the transgene in six out of eleven events we examined. Homozygous T3 transgenic kernels from four events produced significantly less aflatoxins (P ≤ 0.02) than the kernels from the null or B104 controls under field inoculation conditions. The F1 kernels from the crosses between six elite inbred lines with P2c5 and P2c13 also supported significantly less aflatoxins (P ≤ 0.02) than those from the crosses with null plants. The reduction in aflatoxin ranged from 93.7% to 30.3%. Transgenic leaf (T0 and T3) and kernel tissues (T4) were also found to have significantly higher levels of p2c gene-specific small RNAs. Further, homozygous transgenic maize kernels had significantly less fungal growth (27~40 fold) than the null control kernels 10 days after fungal inoculation in the field. The calculated suppression of p2c gene expression based on RNAseq data was 57.6% and 83.0% in P2c5 and P2c13 events, respectively. These results indicate clearly that the reduced aflatoxin production in the transgenic kernels is due to RNAi-based suppression of p2c expression, which results in reduced fungal growth and toxin production.

Effect of rhizosphere microorganisms on aflatoxin contamination of maize

The continued large consumption of maize makes it one of the most important food crops worldwide. However, the yield and quality of maize are greatly affected by global warming, and mycotoxin pollution keeps increasing. The effect of environmental factors, especially rhizosphere microorganisms, on mycotoxin pollution of maize is not completely clear, so we carried out relevant studies. In this study, we found that microbial communities inhabiting the maize rhizosphere, which consists of soil particles firmly attached to roots, as well as the soil, have a significant influence on the aflatoxin pollution of maize. The ecoregion and soil properties also had considerable effects on the microbial structure and diversity. The bacterial communities from the rhizosphere soil were profiled using a high-throughput next-generation sequencing method. The ecoregion and soil properties had considerable effects on the microbial structure and diversity. A comparison of the aflatoxin high concentration group with the low concentration group found that bacteria of the phylum Gemmatimonadetes and order Burkholderiales were significantly more abundant in the high concentration samples. Furthermore, these bacteria were significantly correlated with aflatoxin contamination and could aggravate its contamination of maize. The results of these analyses showed that seeding location could cause significant shifts in the root microbiota of maize, and the bacteria enriched in high aflatoxin contamination area soils should attract special concern. These findings will support strategies for improving maize yield and aflatoxin contamination control.

Evaluation of the Effects of Fertilization and Drying Methods on Pre and Post Aflatoxin Infection in Maize under Busogo Climatic Conditions

The research was conducted in the years of 2020-2021 during the growing seasons such as 2021A started from September 2020 till the end of January 2021 and 2021 B started from February till end of June 2021, in Busogo sector, Musanze District, Northern Province. The purpose of this project was to assess the impact of fertilization and drying methods such as sun drying, dry shelter and kitchen drying on aflatoxin contamination in maize before and after harvesting. The area from which this project was conducted was chosen due to the availability of a lot of number of maize growers who cultivate them not only for consumption but also for trade purpose either processed or non-processed. During this study, a total of twenty-four samples were collected, examined and evaluated for aflatoxin levels in both seasons. In the season 2021A and 2021B sample collection equivalent to twelve in each season was done then dried them within 30 days by using different drying methods such as dry shelter, kitchen drying, sun drying. Randomized Complete Block Design (RCBD) with four treatment of fertilizer combination in four replications was used in this study and all experimental plots were planted with one maize variety (H628) purchased from Rwanda Agriculture and Animal Resources Development Board. Except samples from maize cultivated without fertilizer, level of aflatoxin infection was found to be higher 10 Parts per billion. The East African countries community standard limit of 10 parts per billion which indicate a health risk to the consumer, when comparing the three drying methods employed in this study, the kitchen drying method produced lower levels of aflatoxin (1.6 parts per billion) than the dry shelter (3.2 parts per billion) and sun drying methods (2.9 parts per billion), samples taken from the control plot (T4) stands for no fertilizer application resulted greater levels of aflatoxin with an average of 25.75 prts per billion compared to other treatments which yielded aflatoxin levels of at lower than 10 parts per billion. The use of kitchen drying can be recommended as well as mixture of both organic and inorganic fertilizers when growing maize in order to reduce the level of aflatoxin.

Aflatoxin contamination of maize and groundnut in Burundi: Distribution of contamination, identification of causal agents and potential biocontrol genotypes of Aspergillus flavus.

Aflatoxin contamination of the staples maize and groundnut is a concern for health and economic impacts across sub-Saharan Africa. The current study (i) determined aflatoxin levels in maize and groundnut collected at harvest in Burundi, (ii) characterized populations of Aspergillus section Flavi associated with the two crops, and (iii) assessed aflatoxin-producing potentials among the recovered fungi. A total of 120 groundnut and 380 maize samples were collected at harvest from eight and 16 provinces, respectively. Most of the groundnut (93%) and maize (87%) contained aflatoxin below the European Union threshold, 4 μg/kg. Morphological characterization of the recovered Aspergillus section Flavi fungi revealed that the L-morphotype of A. flavus was the predominant species. Aflatoxin production potentials of the L-morphotype isolates were evaluated in maize fermentations. Some isolates produced over 137,000 μg/kg aflatoxin B1. Thus, despite the relatively low aflatoxin levels at harvest, the association of both crops with highly toxigenic fungi poses significant risk of post-harvest aflatoxin contamination and suggests measures to mitigate aflatoxin contamination in Burundi should be developed. Over 55% of the L-morphotype A. flavus did not produce aflatoxins. These atoxigenic L-morphotype fungi were characterized using molecular markers. Several atoxigenic genotypes were detected across the country and could be used as biocontrol agents. The results from the current study hold promise for developing aflatoxin management strategies centered on biocontrol for use in Burundi to reduce aflatoxin contamination throughout the value chain.

A Low-Cost, Portable Device for Detecting and Sorting Aflatoxin-Contaminated Maize Kernels.

Aflatoxin contamination of maize is a major food safety issue worldwide. The problem is of special significance in African countries because maize is a staple food. This manuscript describes a low-cost, portable, non-invasive device for detecting and sorting aflatoxin-contaminated maize kernels. We developed a prototype employing a modified, normalized difference fluorescence index (NDFI) detection method to identify potentially aflatoxin-contaminated maize kernels. Once identified, these contaminated kernels can be manually removed by the user. The device consists of a fluorescence excitation light source, a tablet for image acquisition, and detection/visualization software. Two experiments using maize kernels artificially infected with toxigenic Aspergillus flavus were implemented to evaluate the performance and efficiency of the device. The first experiment utilized highly contaminated kernels (71.18 ppb), while mildly contaminated kernels (1.22 ppb) were used for the second experiment. Evidently, the combined approach of detection and sorting was effective in reducing aflatoxin levels in maize kernels. With a maize rejection rate of 1.02% and 1.34% in the two experiments, aflatoxin reduction was achieved at 99.3% and 40.7%, respectively. This study demonstrated the potential of using this low-cost and non-invasive fluorescence detection technology, followed by manual sorting, to significantly reduce aflatoxin levels in maize samples. This technology would be beneficial to village farmers and consumers in developing countries by enabling safer foods that are free of potentially lethal levels of aflatoxins.

Evaluation of performance of metal oxide electronic nose for detection of aflatoxin in artificially and naturally contaminated maize

Aflatoxins are of great concern for food safety and security due to their impact on human health and the agriculture economy in developing countries. This study aimed to evaluate the potential use of a field portable metal oxide sensors based electronic nose to detect aflatoxin contamination in Kenyan maize varieties that were artificially and naturally infected with Aspergillus flavus. Mutual information was used to select features from the electronic nose sensor signals for classification of the samples. The effectiveness of selected features to discriminate between the different classes of samples was evaluated by support vector machines and k-nearest neighbour with leave-one-out cross-validation. External validation was also conducted by analysing samples naturally contaminated with A. flavus using the classification model generated with samples that had been artificially inoculated with the aflatoxigenic A. flavus. Cross-validated classification accuracies ranged from 72% to 88% for maize samples artificially inoculated with A. flavus and 61–86% for samples naturally infected with A. flavus. Classification accuracies achieved with external validation for maize samples naturally contaminated with aflatoxins ranged from 58% to 78% and were relatively consistent with accuracies obtained from internal validation. Results suggest that the electronic nose could be a promising cost-effective screening method to detect aflatoxin contamination in maize.

Assessment of Aflatoxin Contamination in Maize and Groundnuts during Storage in Giwa Community, Kaduna State Nigeria

Contamination of food and feed by aflatoxins has become a worldwide cause of public health concern due to its significant impact on human health and crop market value. The present study aimed to assess the aflatoxin contents of maize and groundnut from stores and warehouses in the Giwa community, Kaduna State, Nigeria. A total of ninety (90) grain samples of maize and groundnut were collected between October to December 2020 and analyzed for total aflatoxins using Enzyme-Linked Immuno Sorbent Assay (ELISA). Eighty-four 84(93.3%) of the samples had detectable aflatoxin levels (0.2-9.8ppb), while six 6(6.7%) had none. There was no significant difference (P>0.05) in the mean total aflatoxin content of the grains from stores, warehouses and household foodstuff samples. This could be attributed to agricultural practices and low temperature and humidity storage conditions, which were the same for all the stored grains. Overall, aflatoxin concentrations of the grain samples were within the acceptable limit (10ppb for maize and 15ppb for groundnut) for food safety set by NAFDAC. However, there could be further contamination during storage, particularly when temperature rises and humidity increases. Hence, improved storage conditions and monitoring of grain before sale are recommended to avoid contamination during storage and to ensure a healthy and safe food supply along the trade chain and to the consumers.

Storage conditions and postharvest practices lead to aflatoxin contamination in maize in two counties (Makueni and Baringo) in Kenya

Abstract Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer’s postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R 2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination.

Mitigating aflatoxin contamination in maize: Breeding for stable resistant cultivars

Maize is a major cereal crop for humans and animals. The production and consumption of maize are adversely affected by aflatoxin contamination resulting in reduced grain quality with high health risk to consumers. Unsafe aflatoxin levels above 20 ppb have been reported in maize from farmers’ fields in Ghana. A study was undertaken to evaluate the yield and aflatoxin contamination resistance stabilities of selected hybrids being developed in Ghana. Eighteen maize genotypes (14 hybrids with the following code names: GH01, GH02, GH03, GH04, GH05, GH06, GH07, GH08, GH09, GH10, GH11, GH12, GH13, and GH14 and four local checks: Etubi, Obotantim, Tintim, and Mamaba) were evaluated across six environments in two seasons. Artificial inoculation was done randomly using the side needle injection method 14 days after midsilk at a concentration of 9 × 107 conidia/ml. After the harvest levels of aflatoxin in the harvested grains were determined using high-performance liquid chromatography (HPLC). Data analysis showed that genotypic effects and environmental effects on some traits were consistently significant across environments, which mean that there was useful variation among the genotypes that could be utilized for the development of hybrids. Non-significant genotype by environment interaction effects for grain yield suggests that a promising genotype selected in one of these locations will also be suitable for production in the other locations in the same agroecological zone. GGE biplot analyses provided clear bases for determining stability and performance of the hybrids. Two hybrids have the potential for production in Ejura, Fumesua, Ohawu, Akumadan, and Kpeve and similar agroecological zones. GH04, GH10, and GH01 were lowest yielding, but GH10 was most stable. GH05 was identified as the most promising for production in Ejura, Ohawu, and Akumadan. Again, GH08 was the Vertex genotype for Wenchi environment. Ejura, located in the transition zone, was identified as the ideal testing environment for the hybrids. Most of the hybrids showed low levels of aflatoxin accumulation below 20 ppb despite artificial inoculation. The study revealed GH01, GH05, and GH08 as the most stable among the top yielding hybrids with aflatoxin levels of 11.9, 14.3, and 3.8 ppb, respectively, after artificial inoculation, which can be considered for cultivation as varieties to help mitigate aflatoxin contamination in maize in Ghana and beyond.

Impact of frequency of application on the long-term efficacy of the biocontrol product Aflasafe in reducing aflatoxin contamination in maize.

Aflatoxins, produced by several Aspergillus section Flavi species in various crops, are a significant public health risk and a barrier to trade and development. In sub-Saharan Africa, maize and groundnut are particularly vulnerable to aflatoxin contamination. Aflasafe, a registered aflatoxin biocontrol product, utilizes atoxigenic A. flavus genotypes native to Nigeria to displace aflatoxin producers and mitigate aflatoxin contamination. Aflasafe was evaluated in farmers' fields for 3 years, under various regimens, to quantify carry-over of the biocontrol active ingredient genotypes. Nine maize fields were each treated either continuously for 3 years, the first two successive years, in year 1 and year 3, or once during the first year. For each treated field, a nearby untreated field was monitored. Aflatoxins were quantified in grain at harvest and after simulated poor storage. Biocontrol efficacy and frequencies of the active ingredient genotypes decreased in the absence of annual treatment. Maize treated consecutively for 2 or 3 years had significantly (p < 0.05) less aflatoxin (92% less) in grain at harvest than untreated maize. Maize grain from treated fields subjected to simulated poor storage had significantly less (p < 0.05) aflatoxin than grain from untreated fields, regardless of application regimen. Active ingredients occurred at higher frequencies in soil and grain from treated fields than from untreated fields. The incidence of active ingredients recovered in soil was significantly correlated (r = 0.898; p < 0.001) with the incidence of active ingredients in grain, which in turn was also significantly correlated (r = -0.621, p = 0.02) with aflatoxin concentration. Although there were carry-over effects, caution should be taken when drawing recommendations about discontinuing biocontrol use. Cost-benefit analyses of single season and carry-over influences are needed to optimize use by communities of smallholder farmers in sub-Saharan Africa.

The effect of harvest, sorting and drying practices on aflatoxin contamination of maize

Aflatoxins are the result of fungal metabolites that contaminate agricultural produce and can cause death to both humans and animals. The risks of using contaminated food and feed with aflatoxins have increased due to environmental factors, pre-harvest, post-harvest and socio-economic factors. This study revealed on harvesting, drying, and sorting practices that can reduce aflatoxin contamination. Experiments were designed in three districts; Kilosa, Gairo, and Mvomero with five (5) treatments replicated nine (9) times under farmers’ conditions. Samples were collected during harvesting, drying, and sorting; and analyzed for aflatoxin B1 using High Performance Liquid Chromatography (HPLC) at Tanzania Bureau of Standards (TBS) laboratory. Analysis of variance and comparison of means for moisture content, mold levels, grain damage, and aflatoxin levels were performed using GenStat® Executable release 16 Statistical Analysis Software. Results indicated that aflatoxin contamination levels were lower at maize grain harvested into bags (456.9μg/kg) compared to maize harvesting onto the ground (889.1μg/kg). It was also observed that maize dried on tarpaulin and raised platform had significantly (p&lt;0.05) low aflatoxin levels (65.5 μg/kg, 67.1μg/kg respectively) while maize dried on the ground had higher aflatoxin infestation (179 μg/kg). Again, sorting maize by color significantly (p&lt;0.05) reduces aflatoxin contamination. These results indicate that proper postharvest management of maize, such as harvesting maize on bags, drying maize on tarpaulin, raised platform and sorting maize by color gives the lowest aflatoxin contamination levels. Hence, proper education to farmers on harvesting maize using container/bags and drying maize on raised platform to be established in farmer level.