Consortium of biocontrol agents, plant oils and oil cakes for the management of leaf blight of jasmine caused by Alternaria jasmini

Chemical pesticides are widely used for plant disease management, but their negative impacts on human health and the environment necessitate the search for safer alternatives. Essential oils and oil cakes have shown promising potential as eco-friendly and sustainable solutions for plant disease control. This study aimed to assess the effectiveness of bacterial antagonists, plant-based oils and oil cakes in managing jasmine leaf blight caused by Alternaria jasmini. Among the seven bacterial isolates tested, Pseudomonas indica (AUPP23) exhibited the highest inhibitory activity, reducing mycelial growth by 74.70 %. Tulasi oil (1 %) was the most effective plant oil, completely inhibiting the growth of the pathogen. Neem cake extract at 20 % concentration resulted in the highest reduction in mycelial growth of the pathogen, with a suppression rate of 97.41 %. Consortium of foliar application with P. indica (AUPP23) (0.2 %) + B. subtilis (Bs7) (0.2 %) + tulasi oil (1 %) + neem cake extract (10 %) had the highest PDI of 09.97 % with 87.32 % disease reduction over control, which was comparable to that of mancozeb (0.2 %), which had a PDI of 09.02 % with 88.53 % disease reduction over control. Furthermore, the highest flower output of 114.27 kg/15 cents was reported with the same treatment. These findings indicate that a consortium of plant-derived oils, such as tulasi oil, along with bacterial bioagents and neem cake extract serves as an effective bio-fungicide alternative. In addition to improving flower output, this environmentally benign method effectively manages jasmine leaf blight disease.