Field Evaluation of Iminoctadine Tris 40% WP against Anthracnose Disease of Chilli and Its Impact on Yield

Abstract

This two-season field study evaluated the efficacy of iminoctadine tris 40% WP against chilli anthracnose caused by Colletotrichum capsici at Horticulture Research Station, Mondouri, West Bengal, during 2017–18 and 2018–19. Six fungicidal treatments and an untreated control were evaluated in a randomised block design with three replications. Iminoctadine tris 40% WP at 400 g a.i./ha consistently produced the lowest disease severity among the tested treatments. In 2017–18, the treatment recorded a final percent disease index (PDI) of 12.93% and 73.15% disease control over the untreated control. In 2018–19, the corresponding values were 11.50% and 77.61%. Zineb 75% WP and tebuconazole 25% WG also reduced disease severity, while myclobutanil showed comparatively lower efficacy. Disease suppression was accompanied by higher yield under the experimental conditions. Iminoctadine tris 40% WP at 400 g a.i./ha produced 18.68 q/ha in 2017–18 and 19.72 q/ha in 2018–19, representing yield increases of 62.72% and 49.39%, respectively, over the untreated control. Phytotoxicity observations at the evaluated higher doses during both seasons showed no recorded symptoms across the assessed parameters. Overall, the results indicate that iminoctadine tris 40% WP at 400 g a.i./ha provided the best combined disease-control and yield response among the treatments evaluated under these field conditions.