Prevalence and severity of viral and fungal diseases in selected fruits and vegetables in northern and upper east regions of Ghana

Abstract

This study assessed the incidence and severity of viral and fungal diseases and some agronomic practices affecting vegetable crops in sixty vegetable fields from 4 different irrigation sites located in the Northern and Upper East Regions of Ghana. A descriptive survey was conducted from May to December 2023 to January to May, 2024. Questionnaires were administered to 180 vegetable farmers in total. A field survey identified four major diseases affecting vegetable crops: Cercospora leaf spot, leaf anthracnose, fruit rot, and viral infections. Among the fungal diseases, fruit rot had the highest incidence (42.65%), followed by Cercospora leaf spot (40.00%) and leaf anthracnose (39.58%). However, in terms of severity, viral diseases topped the list with 10.63%, while leaf anthracnose (9.50%), Cercospora leaf spot (9.13%), and fruit rot (8.80%) followed. Seed practices revealed that 1.7–45% of farmers reused seeds from previous harvests, with 11.7–88.3% storing them in airtight rubber containers. Seedling mortality after transplanting ranged widely, affecting 5–95% of farmers. Water sources for irrigation included municipal and irrigation supplies (1.7–60%). Farmers primarily identified new diseases through visual symptoms (1.7–98.3%) and practiced seasonal crop rotation (43–60%). Fungicide use for disease control varied from 3.3–73% among farmers. The findings suggest that poor agronomic practices, including inadequate seed management and irrigation strategies, were the main factors contributing to the widespread occurrence and intensity of fungal and viral diseases on vegetable irrigation farms.