Pathological Assessment of Fungi from Diseased Crops Grown with Contaminated Irrigation Water in Some Selected Local Government Areas of Sokoto State

Abstract

Crop production in Sokoto State is heavily dependent on irrigation, but contaminated irrigation water often introduces pathogenic fungi and heavy metals which compromise crop health. This study investigated the presence of fungal pathogens in crops grown with contaminated irrigation water used in three Local Government Area of Sokoto State which include  Kware, Wamakko, and Tambuwal. The Physicochemical analysis shows that the pH of the water is neutral with 7.18,7.15 and 7.04 from TBW, KW and WMK respectively. The electrical conductivity recorded highest from KW with 1688, then 1685 from WMK and the least was from TBW, dissolve oxygen was higher in TBW and lest recorded was from WMK, the result of BOD recorded highest from WMK with 23.3  followed by 22.9 from TBW and 22.1 from KW, Ca, Mg and Cl were also analyzed with highest ca from TBW WITH 84.0 followed by KW with 68.0 then the least was 30.0 from WMK. Heavy metal analyses were Iron which recorded highest from WMK with 10.5 and lowest from KW with 5.1, copper recorded highest from TBW with 6.4 followed by WMK with 5.5 and KW was the least with 4.3, lead concentration was very minimal across all the sample sites with 0.9,0.8 and 0.4 from KW,WMK and TBW respectively. Zinc recorded higher from TBW with 13.0 and the least was 8.1 from WMK, chromium concentration was recorded from KW with 4.3 and WMK was the least with 2.3. Isolation of fungi from the irrigation water samples shows that both water and diseased crops. Pathogens identified included Aspergillus niger, (10%) Rhizopus stolonifera (10%), Mucor hiemalis (6.66%), Candida tropicalis (6.66%), Penicillium (3.33%), Cladosporium (3.33%), Trichoderma, fusarium (10%), and Aspergillus flavus (10%). Pathogenicity tests confirmed their role in crop spoilage. Results revealed high contamination levels, linking irrigation water to the prevalence of fungal diseases in crops, all the fungal isolated detected from the water samples were also isolated from the diseased crops. The study concludes that irrigation water is a major vector for fungal pathogens and heavy metal stress, threatening agricultural productivity and food safety. Recommendations were made on water treatment, farm sanitation, crop rotation, and policy interventions.