Investigations on Chrysanthemum Leaf Blight Caused by Alternaria alternata (Fr.) Keissler
| dc.contributor.advisor | B.C. Kamanna | |
| dc.contributor.author | Devaraja Odenapur | |
| dc.date.accessioned | 2016-11-10T17:44:36Z | |
| dc.date.available | 2016-11-10T17:44:36Z | |
| dc.date.issued | 2011 | |
| dc.description.abstract | Among the several diseases, Alternaria leaf blight is one of the most destructive foliar disease which causes heavy loss in chrysanthemum. Survey during Kharif/Rabi 2010 revealed that Alternaria leaf blight was severe in all five districts viz., Dharwad, Haveri, Gadag, Koppal and Belgaum. Isolation and morphological studies revealed Alternaria alternata (Fr.) Keissler as causal organism. In cultural studies maximum growth was observed in potato dextrose agar (81.60mm), followed by Richard’s agar (78.50mm). Nutritional requirement of the pathogen were studied with different carbon and nitrogen sources. Among carbon compounds, mean dry mycelial weight of the pathogen was maximum in glucose (359.67mg), followed by sucrose (276.62mg). Among the nitrogen sources, maximum mean dry mycelial weight was observed in Asparagine (383.33mg). In pH studies maximum growth of pathogen found at 6 pH. The maximum growth was observed, when cultures were exposed to alternate cycles of 12hr light and 12hr darkness. Optimum temperature range for the growth of the pathogen was found to be between 25ºC -30ºC. The survival of pathogen in chrysanthemum crop debris was more than 183 days under in all three different conditions viz., refrigerator, glasshouse, Laboratory, Out of nine hosts range studies, sunflower and day flower produced symptoms. Among the five chrysanthemum varieties screened for their reaction to leaf blight under artificial conditions all are show the susceptible reaction. Among ten different fungicides tested in vitro, Propiconazole, Difenconazole, Penconazole and Hexaconazole at 0.1% concentrations completely inhibited the mycelial growth of A. alternata. In case of field evaluation of fungicides Hexaconazole (0.1%) effectively controlled the disease incidence and recorded very less per cent disease index (5.18) which was on par with the Difenconazole (0.1%) having a per cent disease index (5.74). | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/84997 | |
| dc.publisher | UAS, Dharwad | en_US |
| dc.research.problem | Investigations on Chrysanthemum Leaf Blight Caused by Alternaria alternata (Fr.) Keissler | en_US |
| dc.sub | Horticulture | en_US |
| dc.subject | Plant Pathology | en_US |
| dc.theme | Investigations on Chrysanthemum Leaf Blight Caused by Alternaria alternata (Fr.) Keissler | en_US |
| dc.title | Investigations on Chrysanthemum Leaf Blight Caused by Alternaria alternata (Fr.) Keissler | en_US |
| dc.type | Thesis | en_US |