Assessment of Botanical Cakes in Managing Alternaria brassicae in Broccoli Leaf Spot Disease In-vivo

Abstract

In India, Broccoli (Brassica oleracea var. italica L.) is a prominent vegetable crop cultivated during the Rabi season. A prevalent pathogen affecting broccoli is Alternaria brassicae, which causes Alternaria blight and has a global distribution. To mitigate the adverse effects of this disease on crop health, an effort has been made to assess the efficacy of specific botanical cakes and fungicide. The present study aimed to evaluate the efficacy of botanical oilcakes in managing Alternaria brassicae, the causal agent of leaf spot disease in broccoli (Brassica oleracea var. italica L.), under field conditions during the 2022–23 Rabi season at Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj. Eight treatments, including three botanical oilcakes (Neem, Mustard, and Groundnut cakes), their combinations, and a chemical control (Bavistin @ 0.2%), were tested against a control (untreated). Results showed that all treatments significantly reduced disease intensity and improved growth and yield parameters compared to the control. The best botanical treatment, mustard cake @ 400 kg/ha (T2), reduced disease intensity by 52.38% (from 40.6% to 19.33% at 75 DAT) and increased plant height by 18.65% (from 27.13 cm to 32.2 cm), head weight by 82.76% (from 138.8 g to 253.7 g), and head diameter by 49.07% (from 9.73 cm to 14.5 cm), compared to the untreated control. Although Bavistin (T7) was most effective overall, the use of mustard cake demonstrated considerable potential as a sustainable and eco-friendly alternative to chemical fungicides. This organic approach offers a viable option for integrated disease management in broccoli cultivation. Further multi-season and multi-location trials are recommended to validate these findings for broader applicability.