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Research Article
Surveillance of Powdery Mildew Disease on Cashew in Selected Growing Ecologies of Nigeria
Issue:
Volume 14, Issue 3, June 2026
Pages:
47-54
Received:
10 April 2026
Accepted:
21 April 2026
Published:
12 May 2026
Abstract: Cashew (Anacardium occidentale L.) is a major perennial cash crop in Nigeria, yet its productivity is increasingly constrained by many factors of which pests are major, notably powdery mildew, a fungal disease. This study presents a baseline disease audit assessing the occurrence, incidence, severity, and distribution of cashew powdery mildew in six major cashew producing states of Nigeria: Kwara, Kogi, Oyo, Benue, Enugu, and Edo. Field surveys were conducted during the flowering and fruiting period of the year 2024 production season, and a multistage sampling technique was employed. A total of 250 trees were assessed per state, targeted at young, actively growing tissue which are usually susceptible to mildew infection. A 1 sqm quadrants were placed on two opposite sides of the cashew canopies for assessment of affected parts. Powdery mildew incidence and severity were assessed on leaves, inflorescences, apples and nuts using standardized visual scoring methods and damages caused. Powdery mildew was detected in all surveyed states, with overall moderate disease pressure. Mean disease incidence ranged from 28.5% to 46.2% across surveyed states, while severity was highest on cashew apples, followed by leaves and least on the nuts. Disease severity also differed significantly among plant parts (p < 0.05), with highest mean in the apples in Oyo and Kwara States. The state-level disease pressure: low (<30%), moderate (30–45%), and relatively high (>45%) incidence, spatial analysis identified Oyo as high incidence zone, while Kwara, and Kogi States as moderate disease hotspots. The widespread presence of the disease underscores the need for regular disease surveillance and the adoption of integrated disease management strategies. The study provides the first multi-state baseline data on cashew powdery mildew in Nigeria and establishes a reference framework for long-term disease monitoring, extension services, future research and policy formulation.
Abstract: Cashew (Anacardium occidentale L.) is a major perennial cash crop in Nigeria, yet its productivity is increasingly constrained by many factors of which pests are major, notably powdery mildew, a fungal disease. This study presents a baseline disease audit assessing the occurrence, incidence, severity, and distribution of cashew powdery mildew in si...
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Research Article
Spatio-Temporal Distribution and Comparative Analysis of Schistosomiasis and Soil-transmitted Helminthiasis in Plateau State, Nigeria (1990–2025)
Issue:
Volume 14, Issue 3, June 2026
Pages:
55-63
Received:
30 April 2026
Accepted:
14 May 2026
Published:
30 May 2026
Abstract: Schistosomiasis and soil-transmitted helminthiasis (STH) remain major public health concerns in Nigeria, particularly in Plateau State where environmental and socio-economic conditions favour transmission. This study assessed the spatio-temporal distribution and comparative epidemiology of schistosomiasis and STH across Local Government Areas (LGAs) in Plateau State from 1990 to 2025 using secondary data from published literature. Data were stratified into four time periods (1990–1999, 2000–2009, 2010–2019, and 2020–2025) and analysed to identify spatial patterns, temporal trends, and co-endemicity. Results showed that schistosomiasis prevalence was historically high, with values exceeding 60% in some LGAs, but declined significantly in recent years, with near elimination observed in Pankshin (0.0%). In contrast, STH prevalence remained widespread, with persistent moderate-to-high levels in several LGAs, including Jos North (38.3%), Jos South (42.6%), and Wase (49.9%). Spatial heterogeneity was evident, with rural LGAs exhibiting higher schistosomiasis prevalence due to water contact, while urban areas showed increased STH prevalence linked to poor sanitation. The findings highlight differential responses to control interventions, with schistosomiasis showing greater reduction compared to STH. Integrated control strategies combining chemotherapy, water, sanitation, and hygiene (WASH), and geospatial surveillance are recommended for sustainable disease control. This study will provide the first comprehensive spatiotemporal and comparative analysis of schistosomiasis and STH in Plateau State over a 35-year period, bridging a critical evidence gap for Nigeria's neglected tropical diseases (NTDs) elimination efforts. The findings will directly inform the Plateau State Ministry of Health and the Federal Ministry of Health on how to spatially target limited resources, optimize MDA frequency based on local transmission dynamics, and design integrated WASH-NTD interventions. The methodology is replicable for other NTD-endemic states in Nigeria and across sub-Saharan Africa, contributing to the WHO 2030 roadmap goals for NTD elimination.
Abstract: Schistosomiasis and soil-transmitted helminthiasis (STH) remain major public health concerns in Nigeria, particularly in Plateau State where environmental and socio-economic conditions favour transmission. This study assessed the spatio-temporal distribution and comparative epidemiology of schistosomiasis and STH across Local Government Areas (LGAs...
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Research Article
In Vitro Antibacterial Activity and Phytochemical Characterization of Ricinus Communis and Cajanus Cajan Leaf Extracts Against the Causal Agent of Bacterial Wilt
Issue:
Volume 14, Issue 3, June 2026
Pages:
64-72
Received:
20 February 2026
Accepted:
10 May 2026
Published:
10 June 2026
DOI:
10.11648/j.ajbio.20261403.13
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Abstract: Bacterial wilt caused by the Ralstonia solanacearum species complex is a major crop constraint. However, considering the limitations of conventional control methods and the environmental challenges associated with the excessive use of synthetic pesticides, exploring plant-based biopesticides appears to be a promising alternative strategy for sustainable management. It is in this context that the present study was initiated to evaluate the in vitro antibacterial potential and characterize the phytochemical profile of aqueous extracts and fermented leaf extracts from Cajanus cajan and two varieties of Ricinus communis against Ralstonia solanacearum species complex. The extracts were prepared from the leaves and then tested using the agar diffusion method to assess their antibacterial activity, compared with the reference biopesticide NECO 50 EC and chloramphenicol. Qualitative phytochemical sorting was also performed to identify the main groups of secondary metabolites present in the extracts and fermented extracts. Most of the tested aqueous extracts and fermented extracts exhibited antibacterial activity after 24 h of incubation, except for R. communis var. zanzibarensis aqueous extract. The best antimicrobial activities were obtained using the biopesticide NECO 50 EC (22,01 mm) and chloramphenicol (27,98 mm). Fermented extract of C. cajan showed consistent inhibition of bacterial growth at all concentrations, with diameters ranging from 9 to 14 mm. However, the antibacterial activity of the extracts was unstable over time, unlike on the positive controls, whose effect was constant. Phytochemical sorting revealed several groups of bioactive compounds in the aqueous extracts, whereas the fermented extracts contained only polyphenols. The antibacterial potential of C. cajan and R. communis extracts against the Ralstonia solanacearum species complex was demonstrated, in line with their richness in secondary metabolites. However, the temporal instability of their activity highlights the need for further research to explore their potential use in sustainable agriculture.
Abstract: Bacterial wilt caused by the Ralstonia solanacearum species complex is a major crop constraint. However, considering the limitations of conventional control methods and the environmental challenges associated with the excessive use of synthetic pesticides, exploring plant-based biopesticides appears to be a promising alternative strategy for sustai...
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,
Fiyin Tijesunimi Laoye,
Maria Olufunke Bobinihi,
Alaba Olaitan Adeji
