Occurrence of Pythium Root Rot on Cabbage (Brassica oleracea) in Sokoto State, North West Nigeria

Cabbage (Brassica oleracea var. capitata) is a commercially cultivated vegetable crop in Sokoto State, particularly under irrigated fadama agriculture during the dry season. Root rot diseases attributed to Pythium species have been reported across irrigated vegetable farms and are suspected to cause significant seedling and crop losses. This study investigated the occurrence of Pythium root rot on cabbage in irrigated fields across four communities in Sokoto State during the 2023 dry season. Thirty-six farms were surveyed, with root symptoms documented and soil and root samples collected for laboratory analysis. Isolation on selective media identified Pythium aphanidermatum and P. irregulare as the primary species associated with root rot symptoms, confirmed through pathogenicity testing on seedlings. Disease incidence averaged 35 percent, with severe outbreaks occurring in areas of impeded drainage and continuous cropping without soil resting. High soil moisture content was the single strongest predictor of Pythium infection across all sampling sites. Farmer management practices predominantly involved fungicidal drenches applied after visible symptoms appeared, limiting the effectiveness of interventions. The study recommends adoption of raised-bed planting techniques, improvement of drainage infrastructure, and prophylactic applications of phosphonate-based fungicides as integrated management options in irrigated Brassica production systems. Keywords: cabbage, Pythium root rot, irrigated agriculture, Sokoto State, disease occurrence.