2026· International journal of research and innovation in applied science· Vol 11, pp. 1556-1561· 0 citations
Abstract
Tomato (Solanum lycopersicum L.) is a major cash crop in Northern Nigeria, but fungal diseases are widely cited as a principal cause of the persistent gap between smallholder and research-station yields (Mohammed et al., 2023; Usman & Mohammed, 2023). Standardised, farm-level epidemiological data comparing disease burden between contrasting agroecological zones remain scarce. This study determined the prevalence and incidence of five major tomato fungal diseases across eight Local Government Areas (LGAs) in Kano and Kaduna States and compared disease burden descriptively between the two states. A total of 240 tomato farms (30 per LGA) were monitored biweekly over two consecutive growing seasons using standardised photographic field guides and pathologist-verified identification protocols (inter-rater κ ≥ 0.80). Early blight was the most prevalent disease overall, recorded on 86.7% of farms in Kano State and 79.3% in Kaduna State. Because between-state comparisons necessarily used LGA-level means (n = 4 per state) as the unit of analysis to avoid pseudo-replication across clustered farms, these comparisons are reported as descriptive, ecological-level patterns rather than confirmatory population-level tests: Kano State showed a consistently higher late blight burden (74.3% vs. 61.7% prevalence, 95% CI for the difference [9.7, 15.5]) while Kaduna State showed a consistently higher Fusarium wilt burden (73.3% vs. 57.7% prevalence, 95% CI for the difference [-18.7, -12.6]), patterns consistent with the irrigated-lowland versus cooler continuous-monoculture profiles of the two states. Baseline farmer disease-identification accuracy was only 41.0%, confirming that unaided visual diagnosis is insufficient to guide fungicide decisions (Balogun et al., 2023; Yakubu et al., 2024). These findings provide a standardised between-state epidemiological comparison for two leading tomato-producing states and support state-differentiated disease management guidance rather than uniform national recommendations, though confirmatory farm-level modelling is recommended before the between-state differences are treated as definitive.
Background
: High-tunnel tomato cultivation technology is vital for year-round production during the rainy season and for enhancing income among smallholder farmers in north-west Ethiopia. However, its productivity and sustainability are adversely affected by Fusarium wilt (FW) disease. This study assessed the current status of FW epidemics, examined associated biophysical factors, and characterized
Fusarium oxysporum f. sp. lycopersici
(FOL) isolates during the 2024 main cropping season.
Methods
: A total of 75 high-tunnel technologies were inspected in four major tomato-producing districts within two zones. A logistic regression model was used to associate biophysical factors with disease incidence and severity.
Results
: All the surveyed high-tunnels were infected with FW, with incidence ranging from 43.6% (Libo Kemkem) to 60.5% (Dera), and severity from 41.4% to 58.3%. Disease incidence and severity were strongly correlated (P < 0.001) with district, age and leakiness of high-tunnels, seed type and source, plant and weed density, crop rotation, and irrigation method. Elevated incidence and severity (>50%) were notably associated with Dera district, gray soils, older and leaky high-tunnels, local and unknown seed varieties, informal seed exchange, high plant and weed density, fruit-setting stage, absence of crop rotation, and contact irrigation method. Pathogen isolation and characterization study identified eight morpho-culturally and pathogenically diverse FOL isolates.
Conclusion
: FW exhibits extensive distribution across high-tunnel technologies, driven by various biophysical factors and has diverse strains. Therefore, integrated management strategies, including cultural interventions and resistant varieties, are imperative for sustainable high-tunnel tomato production in the study area. Further research on temporal pathogen dynamics and molecular characterization of isolates is also recommended.
Yekoye Abebaw, G. Damessa, E. Adgo et al.· CABI Agriculture and Bioscie...· 0 citations
Late blight disease remains one of the major constraints affecting tomato production worldwide due to its rapid spread and destructive effects on infected plants. This study was undertaken to isolate and identify microorganisms associated with late blight disease of tomato plant in Niger state. A total of thirty diseased tomato samples showing symptoms of late blight were collected from selected tomato farmlands from Bida, Lapai and Agaie Local Government Area of Niger State, Nigeria. The samples were analyzed using standard microbiological and biochemical techniques. Fungal isolates were identified based on their cultural and microscopic characteristics, while bacterial isolates were identified using biochemical tests. The fungi isolated included Phytophthora infestans (40.0%), Alternaria solani (25.3%), Fusarium oxysporum (18.7%), Aspergillus flavus (10.7%), and Phoma destructiva (5.3%). The bacterial isolates recovered were Pseudomonas syringae (38.5%), Xanthomonas campestris (30.8%), Ralstonia solanacearum (20.5%), and Bacillus subtilis (10.2%). Phytophthora infestans and Pseudomonas syringae were the most predominant fungal and bacterial isolates, respectively. The findings of this study indicate that late blight-infected tomato plants harbor diverse fungal and bacterial species that may collectively contribute to disease severity and tissue deterioration. The study therefore emphasizes the importance of accurate identification of microorganisms associated with tomato diseases for effective disease monitoring and management in tomato production.
Aisha Abubakar, Maikudi Habiba Mohammed· The Scientific World Journal· 0 citations
Bacterial wilt caused by Ralstonia solanacearum is a destructive disease severely restricting tomato (Solanum lycopersicum L.) productivity in tropical and subtropical regions. The purpose of this study was to identify novel sources of resistance and explicate the inheritance pattern of bacterial wilt resistance in tomato. A total of 59 genotypes, including open-pollinated lines, hybrids and breeding accessions, were subjected to screening experiments during two consecutive seasons (2022–2023 and 2023–2024) under controlled net house conditions at Centurion University of Technology and Management and natural epiphytotic field conditions at Indian Institute of Horticultural Research - Central Horticultural Experiment Station , Bhubaneswar, India. Disease severity was evaluated using percent disease index (PDI) and area under disease progress curve (AUDPC). The open-pollinated cultivar ‘Utkal Kumari (BT-10)’ exhibited consistent high resistance, with significantly lower AUDPC values (<150 vs >1800 in susceptible checks) and high survival rates (90 %) across environments. Among others, tomato cultivars Arka Samrat, Arka Abhed and JK Desi, demonstrated significant resistance while genotypes such as Pusa Ruby and EW815 were consistently highly susceptible. A segregating F₂ population derived from a cross between resistant ‘BT-10’ and susceptible ‘Pusa Ruby’ exhibited continuous variation in disease response. Chi-square analysis revealed significant deviation from a 3:1 Mendelian segregation ratio (χ² = 72.30, P < 0.01), indicating a quantitative mode of inheritance. These findings highlight the potential of Utkal Kumari and allied resistant lines as donors for resistance breeding and emphasize the need to integrate robust phenotypic screening with molecular approaches for durable and strategic bacterial wilt management in tomato.
D. Debasmita, D. Sunanya, N. P. Bhagbat et al.· Plant Science Today· 0 citations
Wheat (Triticum aestivum) is one of the most widely cultivated strategic crops to ensure food security in Ethiopia. In 2024, soil and root samples were collected from 300 wheat fields across 28 localities in 10 districts during a survey of Ethiopia’s major wheat-growing regions. Root-lesion nematodes were detected in 268 fields across 25 localities in 8 districts. One representative isolate from each positive locality was maintained, resulting in 25 isolates. Infected plants showed stunting and characteristic visible root lesions. The highest nematode density (1,200 ± 100 ind./100 ml) was recovered from root and soil samples from Wudegetna Gefersa, East Sodo district, Gurage zone, Central Ethiopia Regional State (8°18′49.63″N, 38°58′12″E), using the modified Baermann tray method (Whitehead and Hemming 1965). These were identified as Pratylenchus thornei based on morphological characters following Castillo and Vovlas (2007), including a low, flattened lip region with two to three annuli, a well-developed stylet, and a conoid tail with a blunt terminus. The following morphometrics (mean ± SD) were recorded for adult females (n=10): L = 692 ± 24.0 µm, stylet = 16.0 ± 0.43 µm, V = 75.1 ± 2.0%, and tail length = 33 ± 3.8 µm. Specimens were deposited in the Nematology Research Unit Collection, Ghent University, Belgium (UGnem-361–362). Species identity of 14 isolates was confirmed by sequencing the D2–D3 expansion segments of the 28S rRNA gene (PZ224314-PZ224316; PZ228485-PZ228495), the ITS rDNA region (PZ253353-PZ253354; PZ270527) of 3 isolates, and the mitochondrial COI gene (PZ253376-PZ253391) of 16 isolates, following Janssen et al. (2017). The obtained sequences were identical to the reference sequences of P. thornei in GenBank and clustered with other P. thornei sequences in maximum-supported clades. One representative P. thornei isolate from the field population with the highest nematode density (Wudegetna Gefersa) was confirmed by species-specific PCR targeting the 28S and ITS rDNA regions, established as a pure carrot-disc culture, and used for the pathogenicity experiment. Pathogenicity was confirmed under a growth chamber condition (18-23°C with 8 h dark and 16 h light) using a local wheat “cv. Boru” grown in sterilized soil–sand mixture, following Toktay et al. (2012) with minor modifications at test Pi = 100 individuals per pot (yellow stubby Cone-tainers™ (RLC4 type, 1.5 × 5.5 in.; Stuewe & Sons; n = 20)). After 10 weeks of growing, the nematodes were extracted using zonal centrifugation from both the roots and the soil (Hendrickx 1995). The Pf obtained was 427 ± 134.6 per pot (RF = 4.27), and typical brownish root lesions were observed. Recovered nematodes were morphologically and molecularly identical to P. thornei, fulfilling Koch’s postulates. Although ITS2 soil metabarcoding previously indicated the presence of P. thornei from soils associated with a soil-borne pathogen complex of faba bean in the Amhara and Oromia regional states of Ethiopia (Yilma et al. 2025), the present study constitutes the first confirmed report of P. thornei infecting wheat in the Central Ethiopia Regional State based on morphological, molecular, and pathogenicity evidence. Given the well-documented yield losses caused by P. thornei in wheat worldwide, this finding underscores a significant threat to Ethiopian wheat production and the need to step up targeted surveillance, assess the damage, screen for resistance, and initiate effective management strategies.
Yohannes Moges Ferede, Wim M.L. Wesemael, M. Couvreur et al.· Plant Disease· 0 citations
Chilli (Capsicum annuum L.) is an important spice crop widely cultivated in Telangana; however, its production is often affected by several soil-borne fungal diseases. To assess the incidence of these diseases, a roving survey was conducted during Kharif 2025-2026 in five major chilli-growing districts of Telangana, viz., Mahabubabad, Warangal, Khammam, Jayashankar Bhupalpally and Karimnagar, covering 13 mandals and 35 villages. Disease incidence was recorded, and infected plant samples were collected for the isolation and identification of the associated fungal pathogens. The survey showed that Fusarium wilt was the most prevalent soil-borne disease in all the districts surveyed. Among the districts, Khammam recorded the highest mean disease incidence (33.71%), followed by Mahabubabad (22.76%), Jayashankar Bhupalpally (19.72%) and Warangal (17.14%), whereas Karimnagar recorded the lowest incidence (3.74%). Collar rot caused by Sclerotium rolfsii was also observed, but at comparatively low levels. The fungal pathogens isolated from diseased plants included Fusarium spp., Sclerotium rolfsii, Rhizoctonia solani and Macrophomina phaseolina. Variation in disease incidence may be associated with the cultivated varieties, soil type, moisture, temperature, irregular rainfall and continuous chilli monocropping. The findings provide current information on the incidence and distribution of soil-borne fungal diseases in Telangana and highlight the importance of regular disease monitoring.
B. N. Sri, B. V. Sagar, G. Padmaja et al.· Journal of Advances in Biolo...· 0 citations
Purpose: Northern Leaf Blight (NLB), caused by Exserohilum turcicum, is a major constraint to maize production in Ethiopia. This study aimed to investigate the epidemiological drivers and spatial patterns of NLB across major maize-growing regions to inform integrated management strategies. Methods: A field survey was conducted across 18 districts in Oromia, Amhara, and SNNPR regions over two cropping seasons (2021–2022), encompassing 1080 farms. Disease severity was quantified using Percent Severity Index (PSI) and Lesion Area (LA). Spatial, agronomic, and environmental data were analyzed using chi-square tests, correlation analysis, and logistic regression. Results: Pronounced spatial and temporal variations in NLB severity were observed. Oromia exhibited the highest overall disease pressure (PSI: 63.0%), followed by SNNPR (62.1%) and Amhara (60.6%). At the zonal level, Sidama recorded the most severe infections (PSI: 70.6%). Moist and semi-moist mid-altitude zones showed the highest disease pressure (PSI: 70.3%), attributed to cooler temperatures and higher rainfall (> 1200 mm). Temporal trends showed higher severity in 2021 (PSI: 64.0%) than 2022 (60.2%). Cropping systems and cultivar selection significantly modulated disease outcomes. Sole cropping was associated with higher severity (PSI: 68.4%), while intercropping reduced risk (PSI: 54.2%). Susceptible cultivars like BH540 (PSI: 77.1%) suffered severe infections, whereas resistant hybrids such as BH661 (PSI: 51.7%) mitigated impact. Logistic regression identified late planting (OR = 42.53, 95% CI: 17.63–102.61), susceptible cultivars (OR = 24.51, 95% CI: 7.26–82.73), and high-risk agro-ecology (OR = 7.22–16.07) as the top risk factors. Conclusion: This study highlights the multifactorial nature of NLB epidemics. Effective management requires spatially-targeted integrated strategies combining resistant cultivars, optimized planting schedules, diversified cropping systems, and balanced nutrition to enhance maize productivity and safeguard smallholder livelihoods in Ethiopia.
Mesele Haile, Z. Bekeko, Dagne Wegary et al.· Journal of Crop Health· 0 citations