Survey of Soil-Borne Pathogenic Fungi Affecting Some Vegetables in Gerio Irrigation Farm, Adamawa, Nigeria

Introduction: Microorganisms abound in the soil, especially fungi that have high propensity of causing a diverse range of diseases to plants like vegetables. This study sought to establish the presence of some pathogenic fungi present in soil and vegetables grown in Gerio irrigation farm of Adamawa, Nigeria. Methods: From this cross-sectional study, 50 grams each of 3 sets of soil samples from Amaranthus hybridus (African spinach), Hibiscus sabdariffa (Roselle) and Sesamum radiatum (Vegetable saseme) vegetable farms totaling 450g with same sets of stunted sick vegetables to their roots were collected through stratified random sampling techniques. Soil fungi were identified using Waksman’s plate dilution method, while infected plant parts were aseptically processed and cultured on Potato dextrose agar (PDA) prior to identifying fungi using standard fungal detection techniques at Modibbo Adama University of Technology laboratory in the department of Plant Sciences, Yola from July to September 2016. Data was processed using excel and analysed using ANOVA SPSS 23. Results: The study at Gerio irrigation site, Yola, Adamawa State, assessed soil particle types, porosity, moisture content, and fungal populations. Roselle farm soil had the highest sand content (82%), while sesame farm soil showed the highest silt (13%) and porosity (21.9%). Spinach farm soil recorded the highest particle (1.58) and bulk densities (1.45) but the lowest porosity (8.23%). Moisture content was highest in vegetable sesame farm soil (24%) and lowest in spinach soil (10%). Fungal analysis identified five species: Fusarium oxysporum, Fusarium solani, Rhizoctonia solani, Aspergillus niger, and Aspergillus flavus. Fusarium oxysporum was the most prevalent, dominating Roselle plants (58.3%) and soils. In contrast, Aspergillus spp. was rare, with A. flavus absent in spinach and Roselle soils. Discussion: The study accentuates the impact of Fusarium oxysporum and F. solani on vegetables at Gerio irrigation farm, with roselle being highly susceptible. Poor irrigation practices could have exacerbated fungal damage, causing symptoms like wilting and root rot. Measures like crop rotation, fungicides, resistant varieties, and improved irrigation can address these problems. The findings emphasize the importance of understanding soil properties and crop-specific fungal interactions for sustainable agriculture and integrated pest management strategies.