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Abstract:<br/><br/>Bud rot is one of the common diseases in palms cultivation and also considered as one of the important diseases of arecanut, which affect the bud region of the plants. It has also become a limiting factor for successful arecanut cultivation in Meghalaya. Considering the above facts, the present study was conducted with the objectives viz. assessment of yield losses in Meghalaya, isolation of the causal agent and bio-agents from arecanut, studying the behaviour of Phytophthora palmivora and evaluating the efficacy of bio-agents, botanicals and fungicides. The study revealed that yield loss due to the disease was more in West Khasi Hills (16.63%) followed by South Garo Hills (13.60%). P. palmivora was found to be consistently associated with bud rot of arecanut and the pathogen was isolated as well as confirmed for its pathogenecity. Among 8 media viz. PDA, V8 juice agar, oat meal agar, corn meal agar, carrot agar, czapek dox agar, malt extract agar, lima bean agar tested for their effect on mycelial growth of P. palmivora, all media did not differed significantly in growth however, differed in colony characteristics. Under in-vitro conditions, 4 different fungicides viz., Aliette, Ridomil MZ-72, Seetin, Indofil M-45 were tested for bio-efficacy and found highly effective against P. palmivora . Similarly 7 botanicals viz., Garlic, Datura, Artemisia, Lantana, Onion, Duranta, Tricure were tested for bio-efficacy, of them Garlic and Duranta were effective at 5% and 10% concentrations as compared to other plant extracts. Among 9 Trichoderma spp. viz., T. virens, T. harzianum, T. crassum, T. atroviride, T. pseudokoningii, T. longibrachiatum, T. viride (soil), T. viride (phylloplane), Bhoomika (T. viride) tested, all showed antagonistic effect in dual culture, except T. crassum. Under protected conditions in pot experiment, efficacy of 8 treatments viz., Tricure, Ridomil MZ-72 WP, Sectin 60 WG, Aliette 80 WP, T. viride (soil), T. viride (phylloplane), T. harzianum including control, was tested. Of them, Aliette 80 WP showed least (22.86%) PDI. Among bioagents viz., T. viride (soil), T. viride (phylloplane), T. harzianum, of them, T. viride (phylloplane) showed minimum (28.06%) PDI. As botanical, Tricure was tested which showed higher PDI (44.00%) as compared to fungicides and bio-agents. Treatment applied with fungicides attained fast recovery of seedlings and lesser drooping of leaves. Initiation of new leaves was fast and leaf length was more in seedlings applied with bio-agents and fungicides. The best results of this study could be utilized for eco-friendly management of bud rot with strategic evaluation. However, further research work may be taken up in the future for raising good arecanut plantations. |
