Management of Leaf Blight Disease of Medicinal Plants with Bio-agents and Chemical Fungicides

Abstract

Leaf blight affecting medicinal plants like Piper longum, Tylophora indica, and Hibiscus subdariffa is a major issue in West Bengal, causing significant damage year-round. Effective management of this disease is crucial. Several chemical fungicides and Trichoderma isolates were evaluated against the disease of these plants under field condition.  Carbendazim and mancozeb were found to be effective in Piper longum in terms of higher disease control (47.50 & 41.47%) with lower per cent disease incidence (49.87 & 51.47%) and per cent disease index (25.34 & 28.25%) over the control. Although all the Trichoderma isolates were not effective as chemical fungicides but Trichoderma isolate-3 was found to have more efficiency in disease control (35.23%) compared to other two isolates. Mancozeb was treated as the most effective fungicide in T. indica to control the disease (45.07%) with lower disease incidence (54.87%) and disease severity (27.34%) compared to other treatment and control plot. In contrary in H. subdariffa carbendazim was found the most effective fungicide with lowest disease incidence (47.89%) and disease severity (23.37%) resulting higher disease control (47.81%) compared to control. It was followed by cupper oxychloride and mancozeb comparatively with higher disease incidence (49.79 & 51.43%) and disease severity (25.89 & 31.78%). Whether all the Trichoderma isolates did not show significant efficacy as fungicides but Trichoderma isolate-3 showed comparatively good result in disease control (34.32%) over other two isolates and control plot. So, the aforementioned respective fungicides could be used in the control of leaf blight disease of respective medicinal plant. But to control the disease with bio agents more efficient Trichoderma culture need to be investigated.