Survey, characterization and management of leaf blight of Chrysanthemum caused by Alternaria alternata (Fries) Keissler Sujatha H. G.1, Reddy B. Anjaneya2,*, Ramachandra R. K.3, Seetharamu G.K1 1College of Horticulture 2Regional Horticultural Research and Extension Center, University of Horticultural Sciences, GKVK, Bengaluru, 560 065, Karnataka, India 3Horticulture Research and Extension Center, Hogalagere, Srinivasapura, 563138, Karnataka, India *E-mail: arb_agri@yahoo.co.in, ajreddyb007@gmail.com
Online published on 26 June, 2023. Abstract Leaf blight caused by Alternaria alternata is one of the most important foliar diseases hindering the cultivation of chrysanthemum as it infects both leaves and flowers. The survey conducted in eastern dry zone of Karnataka, India revealed highest disease severity at Chikkanahalli in Tumakuru district and the least disease severity (8%) at Mavahalli in Kolar district. The pathogen produced conidia which are typically muriform, dark brown, thick walled. The conidium was up to 33.93–57.42 μm long and 10.44–18.27 μm wide with 6–7 transverse septa and 1–3 longitudinal septa. (Majority of conidia are non-beaked few with short rudimentary dark brown beaks, with a range of 13.05–26.10 μm length). Molecular confirmation of the causal organism was done through PCR amplification and sequencing of ITS region. Invitro evaluation of fungicides revealed, among contact, systemic and combi-products tested copper oxy chloride 50%WP, hexaconazole 5% SC and Zineb 68% + hexaconazole 4% WP and tricyclazole 18% + mancozeb 62% WP respectively were effectively inhibited the pathogen. Invivo evaluation of fungicides revealed, foliar application of copper oxy chloride 50% WP @ 0.3 per cent proved to be highly effective in arresting spread of the disease. Top Keywords Chrysanthemum, Alternaria alternata, Leaf blight, ITS (Internal transcribed Spacer), Characterization. Top |