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
DOI:
10.11648/j.ajbio.20261403.11
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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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,
Fiyin Tijesunimi Laoye,
Maria Olufunke Bobinihi,
Alaba Olaitan Adeji
