Cassava Varieties Research Articles

Response of Soil-dwelling Insects and Weed Communities to Fertilizer Management in Cassava Production: A Site Comparison Study in Agusan Del Sur, Philippines

Aims: Intensification of cassava production through improved fertilizer management requires understanding its impacts on agricultural biodiversity. Study Design: A field experiment using a split-plot design with three replications. Place and Duration of the Study: The study was conducted at two sites (Research Station and farmer's field) from April 2021 to March 2022. Methodology: The study compared eleven fertilizer treatments across two cassava varieties (Lakan 1 and Golden Yellow). Soil-inhabiting insects and weed communities were assessed across all treatments. Results: Soil-inhabiting insects showed significantly higher populations in unfertilized control plots compared to fertilized treatments, with predatory ground beetles (Carabidae) dominating both sites. Shannon's diversity indices (1.58-1.62) indicated moderate insect diversity across sites, suggesting simplified but functional communities. Weed assessments revealed distinct community structures between sites, dominated by perennial grasses from the Poaceae family. While fertilizer treatments significantly influenced soil insect abundance, weed community composition was more strongly affected by site-specific conditions, as demonstrated through cluster analysis. Conclusion: The study demonstrates that agricultural intensification through fertilizer application may impact beneficial soil fauna while having limited effect on weed community structure. These findings suggest the need for integrated, site-specific management approaches that balance nutrient application with biodiversity conservation in cassava production systems.

The haplotype-resolved assembly of COL40 a cassava (Manihot esculenta) line with broad-spectrum resistance against viruses causing Cassava brown streak disease unveils a region of highly repeated elements on chromosome 12.

Cassava (Manihot esculenta Grantz) is a vital staple crop for millions of people, particularly in Sub-Saharan Africa, where it is a primary source of food and income. However, cassava production is threatened by several viral diseases, including cassava brown streak disease, which causes severe damage to the edible storage roots. Current cassava varieties in Africa lack effective resistance to this disease, leading to significant crop losses. We investigated the genetic diversity of cassava and identified new sources of resistance to the viruses causing cassava brown streak disease. The cassava line, COL40, from a South American germplasm collection showed broad-spectrum resistance against all known strains of the viruses that cause this disease. To further understand the genetic basis of this resistance, we sequenced the genome of COL40 and produced a high-quality, haplotype-resolved genome assembly. This genomic resource provides new insights into cassava's genetic architecture, particularly in regions associated with disease resistance. The sequence reveals significant structural variation, including transposable elements, inversions, and deletions, which may contribute to the resistance phenotype. The reference genome assembly presented here will provide a valuable genomic resource for studying the cassava brown streak resistance and will help in accelerating breeding efforts to introduce virus resistance into African cassava varieties. By identifying genetic variants linked to resistance, future breeding programs can develop cassava cultivars that are more resilient to viral threats, enhancing food security and livelihoods for smallholder farmers across regions affected by the disease.

Removing recalcitrance to the micropropagation of five farmer-preferred cassava varieties in Côte d'Ivoire by supplementing culture medium with kinetin or thidiazuron.

In vitro micropropagation is a rapid method of multiplying healthy planting material to control Cassava mosaic disease (CMD), one of a major constraint to cassava production in Africa. However, some cassava varieties have a low propagation ratio under in vitro conditions. The main objective of this study was to improve the in vitro propagation rate of five difficult to grow, farmer-preferred cassava varieties using plant growth regulators. Microcuttings from in vitro plantlets of five recalcitrant cassava varieties (Agbablé 3, Ampong, Bayérè, Bocou 5, Olékanga) were evaluated for their capacity to rapidly regenerate plantlets. Time to root or leaf formation, number of nodes, number of roots, and the in vitro plantlet length were evaluated on nine culture media combinations. We found that among all the cassava varieties studied, the shortest times for leaf (4 to 7 days) or root (9 to 14 days) formation were recorded when the two types of MS media were supplemented with kinetin and thidiazuron as well as on the medium contain half-strength MS without these plant growth regulators. These two hormones evaluated were better for regeneration of leaves, nodes and elongation of in vitro plantlets with optimum concentration of 5 and 10 nM or thidiazuron, and 0.12 or 0.24 µM for KIN. A survival rate between 85-91% was recorded under tunnel conditions and the plantlets appeared to be morphologically normal. The information obtained during this study will be useful for mass multiplication programs of elite cassava varieties.

Identification of peptidome-based biomarkers of cassava mosaic disease resistance in different cassava varieties

Cassava, a major economic crop in Thailand, yielded over 3 million USD in exports in 2023. However, its production has been declining since 2021 due to cassava mosaic disease (CMD) outbreaks, which affect cassava plantations. CMD infections have recently increased due to the scarcity of healthy stems and CMD-resistant varieties, the latter being key to controlling its spread. Developing novel methods is critical for accelerating the cultivation of high-yield, CMD-resistant varieties. In this study, signature peptide patterns were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography-tandem MS (LC–MS/MS) to screen for CMD-resistant varieties. Peptide mass fingerprint (PMF) analyses revealed distinct peptide barcodes across 11 varieties, clearly delineating CMD-resistant and CMD-tolerant phenotypes. LC–MS/MS and orthogonal partial least squares-discriminant analysis (OPLS-DA) further demonstrated clear distinctions between the peptide profiles of different phenotypes. Heatmap and PMF analyses consistently revealed unique peptide patterns across the varieties. Volcano plot analysis identified seven upregulated peptides—TATTVAGS, PAAGGGGG, PNELLSYSE, SSIEEGGS, GGGVGGPL, NNGGGFSV, and GPGPAPAA—in CMD-resistant plants. These peptides were associated with proteins containing CONSTANS-like zinc finger, C2H2-type, GST N-terminal, Tubby-like F-box, nuclear-localized AT-hook motif, auxin response factor, and C2 domains. Altogether, this study identified peptidome-based biomarkers for screening CMD-resistant varieties; however, further validation using larger samples is necessary.

Gender Disparities in the Adoption of Akilimo Cassava Advisory Tools and Productivity in Ogun State, Nigeria

This study investigates Nigeria's low digital agricultural technology acceptance rates by studying gender disparity and developing inclusive policies for both sexes. It presents empirical evidence on the use of the Akilimo Cassava Advisory Tool, a digital tool that provides cassava farmers with agronomic guidance to help them make better decisions. The data for this study was collected through interviews and questionnaires distributed to 329 farmers who cultivate cassava and who were chosen randomly through multistage sampling technique. Descriptive statistics, logit regression model and Average Treatment Effects (ATE) model served as the basis for conducting the analysis. The study reveals that male farmers had higher adoption rates of the Akilimo tools at 33.03% compared to female farmers who adopted at 27.93%. Overall, only 31% of cassava farmers adopted the tools. Their low rate of adoption are due to low awareness of the tool, inability to get the recommended cassava and maize varieties, high herbicide prices and tool skepticism. The barriers to adoption particularly oppressed female farmers which intensified the gender gap in adoption rates. Factors influencing adoption included household farming members, income contributors, native status, cooperative membership, marital status (single), and food expenditure. Male farmers showed superior advantages from Akilimo than female farmers because they received better resources coupled with advisory information. The statistical evidence validates that Akilimo tool adopters achieved higher cassava yields at a significance level (p-value = 0.048). All agricultural farm sizes derive improved productivity benefits from implementing Akilimo cassava advisory tools. Therefore, the Akilimo tool developers should team up with various government agencies to develop new training initiatives to teach farmers about the platform usage. To achieve widespread coverage of these programs, farmer cooperatives and radio broadcasts, along with community demonstrations, should be used. Also, the Akilimo tools developer should develop offline capabilities, which will minimize data expenses.

COMPLIANCE WITH RECOMMENDED PRODUCTION PRACTICES AMONG CASSAVA FARMERS IN EPE LOCAL GOVERNMENT AREA OF LAGOS STATE, NIGERIA

The study was carried out to investigate the factors influencing compliance with recommended production practices among cassava farmers in Epe Local Government Area of Lagos State, Nigeria. A multistage sampling procedure was used to collect data from 107 cassava farmers. Data were analyzed using descriptive statistics such as percentage, mean and standard deviation, and inferential statistics such as compliance index, and probit regression model. The study revealed that the mean age, household size, years of education, years of cassava farming experience and farm size were approximately 48 years, 6 people, 9 years, 14 years and 3 acres, respectively. The findings also revealed that almost all (98.9%) cassava farmers complied with intercropping cassava with maize or cowpea, while majority (72.0% and 58.1%) complied with the use of improved variety of cassava and planting population density of 10,000 per hectare. The results similarly revealed that majority (64.5%) of the cassava farmers fully complied with the recommended production practices. The study also showed that sex (P<0.01), years of formal education (P<0.05), primary occupation (P<0.10), and visitation by extension agent (P<0.10) were the factors that significantly influenced their full compliance with the recommended production practices. The study concluded that majority of the cassava farmers complied with recommended production practices and their compliance was influenced by sex, years of formal education, primary occupation and extension visit. The study therefore recommended that female cassava farmers should be motivated and encouraged to obtain information that will boost their output, and be enlightened on the importance of education to their farming activities.

Influence of Contracted Extension Service Delivery Model on Uptake and Use of Cassava Technologies, Innovations and Management Practices in Nakuru and Busia Counties, Kenya

Adoption of Technologies Innovations and Management Practices (TIMPs) by farmers is critical in improving farmers’ livelihoods. The Kenyan Government, through Kenya Agricultural Productivity and Agribusiness Project (KAPAP), implemented the Contracted Extension Service Delivery Model (CESDM) across various agricultural value chains. In the cassava value chain, nine TIMPS were promoted which included the use of improved cassava planting materials, organic manure/ inorganic fertilizers, rotational crops, intercrops, pest and disease management, drying, milling, blending and collective marketing. Using a cross-sectional approach and a sample of 816 respondents, this study employed a multivariate and an ordered probit to determine the effects of CESDM on adoption of cassava TIMPS in Busia and Nakuru counties of Kenya. The results showed that the CESDM influenced certain practices positively. These included use of improved cassava varieties, crop rotation, fermentation and milling. The CESDM was negatively associated with fertilizer use, intercropping and disease control. Generally, factors that influenced adoption of cassava TIMPS included household size, land tenure, cassava yield, credit use, off-farm employment, ownership of cassava machineries, gender of household head, access to cassava information, higher cassava acreages, cassava experience and agricultural group membership. Factors that explained the extent of use of cassava included household size, gender of household head, land ownership, and age of household head. The study concluded that indeed government support and interventions are key in enhancing adoption of selected cassava TIMPs, and such initiatives are necessary in building a critical mass of trained farmers for increased welfare gains.

Assessment of Heavy Metals and Phytoremediation Potentials of Cassava in Crude Oil Impacted Farmland Soils in Mmahu, Imo State

The concentration of Cr, As, Fe, Ni and Cd in crude oil impacted soils and cassava plant part samples from Mmahu area in Niger Delta, Nigeria and the phytoremediation potentials of cassava were assessed. The samples were collected from three crude oil exploitation sites. In each exploitation site, five farmlands were sampled. Soil samples were collected at the beginning and end of each farmland using soil auger and bulked together to form 15 composite samples. Soil samples were air-dried and sieved to remove root debris. The cassava tubers were collected close to where the soil samples were collected from each sampled farmland. The cassava tuber was peeled and separated into tubers and peels. The plant samples were sun dried and ground using ceramic mortar. The tubers and the peels from the two points were also bulked to get a total of 15 cassava tuber samples and 15 cassava peel samples. All samples were analyzed for heavy metals using Atomic Absorption Spectroscopy (AAS). The results indicated that although Cr, As, Fe and Ni were found present in the soil, they were below the FAO/WHO soil permissible limits, while the value of Cd was far above the limit. It was also found that As, Cr and Cd concentrations were higher in cassava peels and tubers in all the three sites sampled when compared to the soil samples. The results of Contamination Factor (CF) and degree of contamination (Cd) showed Cd to be the highest heavy metal element with the highest CF and Cd value, followed by Fe which is of moderate contamination, while Cr, As and Ni had low CF and Cd. The result of the Pollution Load Index (PLI) of the cassava samples showed that the cassava peels and tubers in all three sites were polluted. The results of the bioaccumulation factors (BAF) of heavy metals in cassava peels and tubers indicated that cassava has high efficiency in bioaccumulation of these metals. The results obtained on Bio-translocation Factor (BTF) implied that cassava has in-situ phytoremediation potentials but there were variations in the elements translocated across the three sites. These variations might be attributed to the variation in cassava varieties across the three sites.

Cocooning with Cassava: Exploring the commercial rearing and seed production potential of Samia ricini Donovan on different Cassava varieties

Cocooning with Cassava: Exploring the commercial rearing and seed production potential of Samia ricini Donovan on different Cassava varieties

Physicochemical characterization of flours from cassava varieties

Physicochemical characterization of flours from cassava varieties

Identifying cassava production constraints, farmers preferences, and cassava mosaic disease perceptions in Togo: insights for a participatory breeding approach

BackgroundCassava is a crucial food security crop in Togo and the most significant root crop in terms of area under cultivation and production volume. However, its production is predominantly carried out by subsistence farmers using low-yielding landraces. Several constraints impede cassava production, threatening its sustainability in the country. The low adoption of improved varieties developed by the International Institute of Tropical Agriculture (IITA) underscores the need for a participatory approach to research and development. This study aimed to identify the cassava varieties grown, major production constraints, farmers' trait preferences, and perceptions of Cassava Mosaic Disease (CMD) through Participatory Rural Appraisal (PRA).MethodsThe study employed a multistage random sampling procedure to select regions, districts, and villages based on cassava production levels. The survey involved 83 men and 57 women in group interviews and 600 farmers in individual interviews: 200 in the forest–savanna transition, 180 in the rainforest, 120 in the wet savanna, and 100 in the dry savanna. Content analysis was used for qualitative data, and quantitative data were analyzed using descriptive statistics and comparative analyses, including Chi-square tests to assess differences in perceptions and preferences.ResultsThe PRA revealed key constraints to cassava production, including inadequate capital, CMD, post-harvest physiological deterioration (PPD), and the non-availability of clean planting materials. Traits such as high yield, pest and disease resistance, early maturity, high dry matter content, delayed root deterioration, poundability, and taste were highly valued by farmers. CMD was identified as a significant disease, causing yield losses, with various causes and management practices reported. The study highlighted the necessity for a sustainable cassava seed system, as farmers pointed out the lack of improved varieties and clean planting materials.ConclusionThis study provides essential insights into cassava farming practices, production constraints, and farmers' preferred traits, laying the groundwork for a participatory breeding program in Togo. Addressing low-yielding varieties and diseases, particularly CMD, is critical for enhancing cassava production and ensuring food security.

Investigating the relationship between cooking time, dry matter and sensory attributes of boiled cassava

Cassava is a major staple food in many tropical regions, but certain varieties remain hard and difficult to chew even after boiling, making them less appealing to consumers. Preferences generally lean toward cassava roots that cook quickly and possess a sweet taste. This study explored the relationship between cassava’s dry matter content and optimal cooking time (CT), specifically examining how these factors relate to sensory attributes like softness and chewability. Twenty cassava varieties, aged 10 to 12 months, were freshly harvested from the International Institute of Tropical Agriculture (IITA) research farm in Ibadan. After harvesting, the roots were peeled, washed, diced and then boiled. Standard procedures were used to evaluate each variety’s cooking time, dry matter content and sensory properties. The sensory assessment focused on the softness and chewability of the cassava roots, both are key attributes that influence consumer satisfaction. The results indicated that most sweet cassava varieties with a dry matter content above 35 % cooked within 25 minutes or less, achieving a soft texture with easy chewability. Statistical analysis using Pearson’s correlation coefficient revealed a strong positive relationship between sensory softness (r > 0.94) and chewability (r > 0.81) in varieties that had a CT of 25 minutes or less indicating that the softer a cassava variety is, the more chewable it is. This correlation underscores that dry matter content and cooking time are significant predictors of sensory quality in boiled cassava. This study emphasizes that cassava varieties with high dry matter content and shorter cooking times are not only easier to cook but are also better suited as a primary energy source in regions where cassava is a dietary staple. Consumers prefer varieties that cook quickly and have a soft, easily chewable texture, providing important insights for cassava breeding and selection programs. By focusing on these qualities, cassava breeders can develop varieties that meet consumer demands, enhancing the appeal of cassava as a food source. This research supports ongoing efforts to improve cassava quality, ensuring that it remains a versatile and desirable staple crop in the tropical regions where it plays a critical role in the diet. Key words: dry matter, cooking time, chewiness, softness, sensory properties

Variety-specific responses to climatic and edaphic factors in cassava productivity

Despite cassava’s significance as a staple crop in tropical and subtropical regions, there is limited understanding of how specific environmental factors influence the productivity of different cassava varieties. This study investigated the complex relationship between environmental factors and cassava yield traits such as fresh root yield (FRY), dry root yield (DRY), starch content (SC) and harvest index (HI) using data obtained from six cassava varieties cultivated for five seasons (2014 to 2019) across nine major locations in Thailand. A total of 41 distinct environmental trials were conducted, representing a range of conditions encompassing various rainfall and temperature patterns, as well as soil characteristics. Field experiments were conducted using a randomized complete block design with four replicates at each location. Climatic data, including air temperature and precipitation, along with soil parameters, were recorded and analyzed to assess their impact on cassava yield traits. Regression analysis revealed distinct coefficients for environmental factors affecting different yield parameters. Cumulative precipitation during 4-5 months after planting (MAP) and 6-10 MAP, as well as the average air temperature during 2-3 MAP and 6-10 MAP, positively influenced cassava yield. However, negative correlations were observed between soil organic matter and HI. Furthermore, the average air temperature at 4-5 MAP, 6-10 MAP, and 1-10 MAP negatively impacts FRY and DRY, while cumulative precipitation during 1 MAP and 2-3 MAP negatively impacts the HI and SC traits. Varieties exhibited varied responses to environmental factors, emphasizing the need to consider specific variety responses for accurate interpretation. The study introduces a novel approach for selecting specific cassava genotypes adapted to distinct environmental conditions by grouping regression coefficients across evaluated parameters. These findings provide insights for optimizing agricultural practices to enhance cassava productivity and contribute to sustainable crop cultivation.

Interactive Effect of Irrigation Supplementation, Compost‐Fertilisation and Resistant Cassava Varieties on the Control and Management of CMD and CBSD, Incidences and Severity Through Morphological Detection Technique

ABSTRACTThe field experimental study was conducted to investigate or determine and analyse the interactive effect of better agronomical practices such as cropping system, irrigation, compost‐fertilisation, planting dates and resistant varieties on the cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) disease presence, incidences and severity through morphological detection technique. The qualitative and quantitative primary data were collected and analysed, through Generalised Model Analysis of Variance (ANOVA), linear regression analysis, GENSTAT and JMP Pro software from this research field experiment study which were laid out in a RCBD design with three blocks and four replications in different location sites. The study took place in Mara and Coastal regions, at Nyasirori Butiama district and Nyegina and Busungu‐Majita Musoma rural district and Msoga Bagamoyo Coast region between October 2021 and August 2023. The results findings show that the disease incidence and levels of severity varied or differed significantly among the four location sites and between the two provinces or zones, Coastal and Mara of the Lake zone, at p < 0.001 level of significance. However, the findings show that there were greater levels of disease incidence and severity in Mara region means (1.9199) particularly Nyegina and Busungu‐Majita villages (2.034632) and (2.0002706), respectively, than Msoga Coast region and Nyasirori Mara region, which both recorded low levels of disease incidence and severity of (1.8509) and (1.65536), respectively. But likewise, the higher mean for disease severity scale score showed to decline progressively from (4.2 ± 0.24) Nyegina, (3.2 ± 0.14) Busungu‐Majita, (2.5 ± 0.2) Msoga and (2.0 ± 0.21) Nyasirori having the lowest level of severity. Moreover, the results also found that there was significant influence at p < 0.001 level of significance with agronomic practice treatment, particularly the application of compost FYM + solely or in combination with irrigation supplementation on reducing and controlling the disease incidence and severity, similarly with growth stage and varietal influence. However, conversely again, the result findings had shown significant reduction and management of the disease incidence and severity levels following treatment application of agronomic practices with FYM and Fertilisation (1.817703), Monocropping + FYM + Irrigation (1.8238636) and Irrigation + FYM + Crop rotation (1.7921402) treatments. Similarly, with the varieties influence, particularly with Mkuranga 1, Kipusa, Chereko and Kiroba, had shown the lowest means (1.285871), (1.474808), (1.711939) and (1.819277), respectively, among the varieties tested. However, the best results for disease prevention, management and control, and thus the recommended application rates of compost FYM + Fertiliser materials were found to be lower and/or ranging between 40 and 60 kg per row equivalent to 20.0–32.0 t ha−1 application rates and 30 kg NPK and 10 kg CAN ha−1 depending on soil type (i.e., too poor and too sandy or sandy–sandy loam) and fertility status of the soil, since even lower rates still have shown significant control. Finally, this will have a tangible benefit of reducing the diseases pandemic to farmers and cassava crop stakeholders, agriculture industry sector on the increased crop productivity performance, yield and more importantly the government policy on increased use and application of compost FYM and fertilisers and a very low cost of production countrywide.

The Transcriptome Response of African and South American Cassava (Manihot esculenta) to Infection by East African Cassava Mosaic Virus‐Uganda

ABSTRACTCassava mosaic begomoviruses (CMBs) cause the economically important cassava mosaic disease (CMD) in cassava. In this research, we investigated potential new sources of resistance to CMD. Fourteen cassava varieties were tested for resistance to the major CMB, East African cassava mosaic virus‐Uganda (EACMV‐Ug). Six African cassava varieties (72‐TME 14, TME 204, TZ 130, Nase 1, Nase 3 and Nase 14) expressed no or mild disease symptoms with low viral load and therefore have been classified as resistant. South American varieties showed severe leaf symptoms and supported high viral load. Nase 3 (resistant), TZ 130 (resistant) and Ebwanateraka (susceptible) were subjected to RNA‐sequencing (RNA‐Seq) to identify putative CMD resistance genes and mechanisms. Transcriptome analysis of three cassava varieties at 2, 4, 7, and 28 days after grafting (DAG) revealed the largest number of differentially expressed genes (DEGs) upon virus infection in Nase 3 (4228) with 1725 genes uniquely over‐expressed. Additionally, early induction of heat shock proteins and transcription factors such as ethylene‐responsive transcription factor (ERF), teosinte‐like, cycloidea and PCF1 (TCPs), heat stress transcription factor and basic leucine zipper were observed in the resistant varieties. These results suggest that resistant varieties maintain a low titre of EACMV‐Ug by activating specific stress‐response genes early. The role of these genes in plants remains to be investigated but offers insights into the molecular mechanism of resistance to CMD.

Identification of the cassava NADP-ME gene family and its response and regulation in photosynthesis.

NADP-malic enzyme (NADP-ME) is a crucial enzyme in C4 photosynthesis, responsible for the decarboxylation of malate in bundle sheath cells, enhancing the photosynthetic efficiency of C4 plants. Cultivated cassava exhibits high photosynthetic efficiency and biomass, and previous studies classify it as a C3-C4 intermediate type. The biomass of cassava correlates positively with photosynthetic rate, and the promoter region of MeNADP-ME3 contains insertion selected in cultivars different from wild ancestors. Four MeNADP-ME genes were identified in the cultivated cassava variety AM560, with promoter regions enriched in light-responsive elements. Phylogenetic and conserved domain analyses revealed that all subtypes are plastidic dicotyledonous types, closely related to AtNADP-ME4, with unique N-terminal domains in MeNADP-ME2 and MeNADP-ME3 specific to cassava, suggesting new functional roles. Subcellular localization showed predominant chloroplast localization, with greater involvement in leaf physiological processes in the cultivated variety SC205. These findings suggest that the NADP-ME family in cultivated cassava has been evolutionarily selected for photosynthesis. Further investigation revealed that MeNADP-ME3 is highly expressed in leaves and regulated by light intensity. Co-expression network analysis of shade-treated transcriptomes and transcription factor-promoter predictions showed that Indel sites in the MeNADP-ME3 promoter are bound by MeYABBY1, forming a regulatory network with other photosynthesis-related genes. This suggests that MeNADP-ME3 plays a role in C3-C4 intermediate photosynthesis during the evolution from wild to cultivated cassava, with other family genes also evolving towards photosynthetic functions. Our study lays the foundation for future functional research on the MeNADP-ME family and provides insights into the mechanisms underlying the high photosynthetic efficiency of cultivated cassava.

Effect of Cell Wall Neutral Sugars and Uronic Acid Compounds on Cassava (Manihot esculenta Crantz) Retting Ability

Aims: Evaluate the effect of cassava cell wall neutral sugars and uronic acids on the ability of cassava to be retted by a traditional starter (sta_96). Place and Duration of Study: Sample: collected from a farm in the Center region in Cameroon. All the analysis were performed at the Department of Microbiology of the University of Yaounde 1 in Cameroon, between June 2024 and December 2024. Methodology: height (08) different local cassava varieties 12 months aged were submitted to fermentation with Sta_96 and their retting kinetic parameters (retting rate and retting times) were assessed by penetrometry. Furthermore, their parietal compounds (neutral sugars and uronic acids) and non-parietal compounds (reducing and total sugars) were analyzed by spectrophotometry and the data obtained were submitted to correlation analysis. Results: It was observed that the roots of the VB 3, CB 1, CB 2, sweet, 6M, and CR varieties softened more easily, with fermentation rates ranging from 1.04 ± 0.88 to 1.75 ± 0.23 cm/h and retting times ranging from 42.64 ± 7.07 to 50.64 ± 0.44 h. The roots of the VB 1 and VB 4 varieties softened with greater difficulty. Negative correlations (-0.79 and -0.881 respectively for neutral sugars and uronic acids) were observed between neutral sugars, uronic acids and softening rate, suggesting that these compounds increase cassava’s retting time by decreasing it fermentation rate. This study shows that the cassava’s softening ability is linked to the neutral sugars and uronic acids content in cassava root walls. Conclusion: Taking into account the cell wall composition in the formulation of starters can lead to a standardization of the cassava roots retting time.

Impact of Selected Starters and Cassava Varieties on the Proximate, Rheological, and Volatile Profiles of Lafun.

Spontaneous fermentation is currently used to produce lafun from cassava, leading to inconsistent product quality and decreased safety. Using starter cultures and optimising the selection of the raw materials can overcome this. This study evaluated the impact of various lactic acid bacteria (LAB) starters and varieties of cassava (bitter: IBA30527; vitamin A fortified bitter: IBA011371; and sweet: TMEB117) on the proximate, rheological, and volatile profiles of lafun. The varieties were fermented with four selected LAB (two strains of Weissella koreensis, Lactococcus lactis, and Leuconostoc mesenteroides). The use of fortified cassava showed higher potential to improve the quality of lafun. The combination of fortified cassava and Leuconostoc mesenteroides gave the highest nutritional value (ash: 4.37% cf. 1.33%; protein: 3.08% cf. 0.87%; and fibre: 7.43% cf. 1.43%). Fermenting the fortified cassava with Weissella koreensis-2 produced lafun gruel with the best viscoelastic properties, indicating an overall better product quality. The fortified cassava fermented with combined cultures of W. koreensis-1 and L. lactis resulted in a product with lower levels of carboxylic acids (cheesy) and lipid oxidation products (fried, rancid) but higher concentrations of carotenoid-derived compounds (fruity). The use of LAB in the controlled fermentation of fortified cassava could be a sustainable alternative to improve the physical, nutritional, and flavour properties of lafun.

High-Throughput Field Screening of Cassava Brown Streak Disease Resistance for Efficient and Cost-Saving Breeding Selection

Cassava brown streak disease (CBSD) remains the most severe threat to cassava production in the Great Lakes region and Southern Africa. Screening for virus resistance by subjecting cassava to high virus pressure in the epidemic zone (hotspots) is a common but lengthy process because of unpredictable and erratic virus infections requiring multiple seasons for disease evaluation. This study investigated the feasibility of graft-infections to provide a highly controlled infection process that is robust and reproducible to select and eliminate susceptible cassava at the early stages and to predict the resistance of adapted and economically valuable varieties. To achieve this, a collection of cassava germplasm from the Democratic Republic of Congo and a different set of breeding trials comprising two seed nurseries and one preliminary yield trial were established. The cassava varieties OBAMA and NAROCASS 1 infected with CBSD were planted one month after establishment of the main trials in a 50 m2 plot to serve as the source of the infection and to provide scions to graft approximately 1 ha. Grafted plants were inspected for virus symptoms and additionally tested by RT-qPCR for sensitive detection of the viruses. The incidence and severity of CBSD and cassava mosaic disease (CMD) symptoms were scored at different stages of plant growth and fresh root yield determined at harvesting. The results from the field experiments proved that graft-infection with infected plants showed rapid symptom development in susceptible cassava plants allowing instant exclusion of those lines from the next breeding cycle. High heritability, with values ranging from 0.63 to 0.97, was further recorded for leaf and root symptoms, respectively. Indeed, only a few cassava progenies were selected while clones DSC260 and two species of M. glaziovii (Glaziovii20210005 and Glaziovii20210006) showed resistance to CBSD. Taken together, grafting scions from infected cassava is a highly efficient and cost-effective method to infect cassava with CBSD even under rugged field conditions. It replaces an erratic infection process with a controlled method to ensure precise screening and selection for virus resistance. The clones identified as resistant could serve as elite donors for introgression, facilitating the transfer of resistance to CBSD.

Costs and Returns Analysis of Cassava Production in Ijebu-North Local Government Area, Ogun-State, Nigeria

The study on Costs and Returns of Cassava production was carried out in Ijebu-North local government area of Ogun state in Nigeria in 2023. Given the importance of cassava in the lives of the farmers and the general public in Ijebu-North LGA, there is need to examine the current trend whether the farmers make profit or not by engaging in cassava production per hectare in the area. This gap will help to encourage farmers to cultivate cassava as a means of improving family living standards. The study described the socio-economic characteristics of the farmers and determined the farm profit per hectare of the cassava farmers. A multi-stage sampling technique was used to select one hundred and twenty (120) cassava farmers as respondents. The tools used for data collection were questionnaire and interview schedule. The data were analyzed with descriptive statistics and profitability analysis. The results showed that 75.8% of the cassava farmers are male, 79.2% of the cassava farmers are married, 50.8% are within the age bracket of 51 years and above, 99.2% of the respondents are educated i.e. they have obtained at least a First school leaving certificate, 50% have an household size of 6-10 persons per family, 65.8% of the respondents have a farming experience of 11 years and above, 47.5% of the respondents have a farm size of 4ha and above and 100% of the respondents have personal savings as their major source of capital. The Profitability analysis revealed that the total variable cost (TVC) of producing cassava per hectare was N185,500 and the total fixed cost (TFC) of producing cassava per hectare was N72,015 giving a total cost (TC) per hectare of N257,515. The total revenue generated per hectare was N368,000 with a gross margin of N182,500. The finding further revealed that a profit of N110,485 with N1.43k made on every naira invested into the business. On cassava production constraints, the farmers ranked Lack of Credit/loan facilities, Poor extension facilities and Lack of improved cassava varieties as the three top major constraints. The study recommends that youths should be encouraged to engage themselves in cassava production on a large-scale basis in the study area.