Spatial variability and key determinants of wilt complex disease: Insights from a survey in major lentil growing areas of Ethiopia

Lentil ( Lens culinaris ) is the most vital legume crop for dietary protein and income source to smallholder farmers in Ethiopia. However, its production and productivity are severely constrained by soilborne diseases, particularly the lentil wilt complex disease. The disease is caused by a combination of soilborne pathogens such as Fusarium oxysporum , Rhizoctonia solani , Sclerotium rolfsii , and Pythium species resulting in significant yield losses. Lentil wilt complex caused by Fusarium spp . is the predominant lentil wilt causal pathogen. The objectives of this study were to assess lentil wilt distribution, incidence, and determine its association with agroecological and agronomic cropping practices in Ethiopia. A survey of 170 lentil fields was conducted during the 2023 main cropping season in eight major lentil growing districts. Disease incidence data was analyzed using descriptive statistics and χ2-based correspondence analysis to map associations with independent variables. The association of disease incidence with biophysical factors were analyzed using logistic regression. The disease was present in all fields, with incidence ranging from 15.6% in Siyadebenawayu to 57.2% in Lume. The study showed that highly significant associations (P ≤ 0.001) between disease incidence and variables of district, altitude, planting date, soil type, drainage, seedbed preparation, and weeding practices. Plant population and growth stage significantly influenced outcomes (P ≤ 0.05), while previous crop, fungicide, and fertilizer application had no significant impact (P ≤ 0.05). Logistic regression showed higher wilt incidence in Lume (6.2 times) than Siyadebrenawayu, local varieties (6.2 times) than improved varieties, poorly drained (5.1 times) than well-drained soils, and black soil (2.6 times) than sandy loam. The findings indicated the need for targeted crop and cultural practices to reduce lentil wilt complex and improve sustainable production in Ethiopia's main lentil growing areas.