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Researcher Jhala, Priyanka
Advisor Mali, B. L.
Source KrishiKosh-Indian National Agricultural Research System
Content type Text
Educational Degree Master of Science (M.Sc.)
Publisher MPUAT
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Plants (Botany) ♦ Specific topics in natural history ♦ Technology ♦ Management & auxiliary services ♦ General management
Subject Keyword Management ♦ Purple Blotch of Onion ♦ Allium Cepa ♦ Alternaria Porri ♦ Management of Purple Blotch of Onion (allium Cepa L.) Caused By Alternaria Porri (ellis) ♦ Plant Pathology
Abstract The onion (Allium cepa L.) is one of the most important commercial vegetable crops grown through out the world. The purple blotch of onion (Alternaria porri) is one of the serious disease causes considerable losses in quantity and quality. Investigations were aimed to workout cultural and morphological characters, to find out susceptible age of host, estimation of yield loss in field conditions, effect of environmental factors on disease development, host plant resistance and to develop management strategy through the use of fungicides and botanicals. The symptoms observed in the disease samples collected during Rabi season 2014 from Bhuwana, Udaipur identical to purple blotch of onion. The pathogen was isolated, purified and identified on the basis of cultural and morphological characteristics as A. porri and their pathogenicity was confirmed. The disease showed considerable damage to onion. Sixty-days-old plants were more susceptible for infection of A. porri. However, susceptibility increased with increased age and after 60-days age decreased in susceptibility was recorded. In field trial conducted for yield loss estimation revealed that maximum yield loss (50.11%) was obtained in control plots followed by one, two and three spray of Mancozeb @ 0.2 per cent concentration. In relation to environmental factors study, temperature ranged from 13 to 32°C, relative humidity more than 75 per cent, wind velocity 2.4 Kmph, sunshine 8.4 hrs and optimum rainfall was found favorable for purple blotch disease development. Among 5 cultivars of onion Nasik red showed susceptibility and Agrifound light red showed resistance reaction against A. porri infection. Out of the six fungicides tested in vitro, Difenaconazole completely inhibited the mycelial growth of A. porri at concentrations of 250, 500, 1000 and 2000 ppm, followed by Tebuconazole at 1000 and 2000 ppm. Neem formulation Azadirachtin was found effective in vitro followed by Garlic extract and Neem oil proved to be least inhibitor. Under pot culture study, combination of Difenaconazole and Azadirachtin was found most effective when applied as foliar spray. The application of fungicide and botanical resulted in significantly great disease control, over their individual applications as well as over untreated control.
Educational Use Research
Education Level UG and PG
Learning Resource Type Thesis
Publisher Place Udaipur
Size (in Bytes) 537.55 kB
Page Count 73