Field evaluation of tomato ( Solanum lycopersicum ) varieties for resistance to early and late blight diseases in Baitadi, Nepal

Tomato is a high-value vegetable crop of significant economic and nutritional importance in Nepal. However, its production is severely constrained by early and late blight, leading to heavy yield losses and increased fungicide dependence. An experiment was conducted in Baitadi District between February and August 2025 to identify resistant varieties. Seven tomato varieties (NS2535, Naveen 2000+, Shivam, Manisha, Sultan, BL410, and Sneha Super) were evaluated using a randomized complete block design with three replications. Varieties differed significantly (p < 0.05) in disease incidence, severity, yield, and growth. BL410 exhibited the lowest late blight incidence (66.6%) and severity of late blight (12.7%) and early blight (26.9%). While early blight occurred in all varieties (100% incidence), late blight significantly varied among cultivars. Naveen 2000+ had the highest yield (89.6 t/ha) with low late blight severity (8.0%), followed by BL410 (71.4 t/ha). In contrast, Manisha and Sneha Super recorded the maximum late blight (38.3%) and early blight severity (63.8%), indicating susceptibility. Disease severity was negatively correlated with yield, highlighting the importance of disease management for yield improvement. The study concludes that BL410 and Naveen 2000+ are suitable for Baitadi conditions due to high yield and disease resistance, offering a practical option for sustainable tomato production.