Effectiveness of Different Fungicides in Combating Tomato Powdery Mildew in Karnataka

Field experiment was carried out to know the effect of different fungicides against powdery mildew of tomato during two Kharif seasons of the year 2022 and 2023. Among the nine treatments, combination fungicides were significantly (p<0.05) more effective than solo fungicides. Picoxystrobin 6.78% + Tricyclazole 20.33% SC applied at 2 ml/l achieved the lowest percent disease index (PDI) of 14% in the first season, with a 74.77% reduction over the control (55.50% PDI). This was closely followed by Azoxystrobin 18.2% + Difenoconazole 11.4% SC at 1.2 ml/l, which recorded a PDI of 14.50% and a 73.87% reduction. In the second season, similar trends were observed with Picoxystrobin 6.78% + Tricyclazole 20.33% SC achieving a PDI of 13.50% and a 74.53% reduction, followed by Azoxystrobin 18.2% + Difenoconazole 11.4% SC with a PDI of 14% and a 73.58% reduction. Pooled data from both seasons confirmed these findings, showing Picoxystrobin 6.78% + Tricyclazole 20.33% SC with a PDI of 13.75% and a 74.65% reduction, and Azoxystrobin 18.2% + Difenoconazole 11.4% SC with a PDI of 14.25% and a 73.73% reduction. The highest PDIs were noted in the Carbendazim 50% WP and Hexaconazole 5% SC treatments. The study highlights the inefficacy of relying on a single fungicide due to resistance development, suggesting combination fungicides as a more effective strategy for managing powdery mildew in tomatoes. It is possible advancing with broader integrated disease sustainable management strategies to protection of environment, crop protection and yield.