Studies on Leaf Blight of Bt Cotton Caused by Alternaria spp.
dc.contributor.advisor | S. A. Ashtaputre | |
dc.contributor.author | Anil G. H | |
dc.date.accessioned | 2016-11-23T15:32:18Z | |
dc.date.available | 2016-11-23T15:32:18Z | |
dc.date.issued | 2013 | |
dc.description.abstract | Cotton is a major fibre crop of global importance and has high commercial value next to food grains. Among the various diseases, Alternaria leaf blight disease is gaining importance due to its increased incidence. A survey was carried out during kharif 2012 in North Karnataka. The maximum disease was recorded in Raichur, Belgaum and Bellary districts. Morphological variability test showed that conidia of different isolates were septated by 1-7 vertical and 3-9 horizontal septe, the isolates from Shaktinagar and Raladoddi showed maximum size of 34.60 × 7.40 and 33.55 × 9.10 μm, respectively. The least size of the conidia was recorded in Dharwad (11.29 × 2.56 μm) followed by Agsikoppa (14.45 × 3.62 μm). Among the twelve isolates, eight isolates showed resemblance with conidial measurements of Alternaria macrospora descried by Ellis M. B. and remaining four isolates were found to be different from Alternaria macrospora morphologically. Maximum width of mycelia was observed in Tagalladoddi (1.99 μm) followed by Navali (1.85 μm) isolates on potato dextrose agar. Five isolates showed irregular and seven isolates showed smooth colony margin. Chicknasbi, Kadagammanadoddi and Tagalladoddi isolates showed excellent sporulation on PDA. All the isolates inoculated on healthy cotton plant showed symptoms. More variability was observed between Tagalladoddi and Raladoddi isolates and less variability was observed between Annigeri and Dharwad through molecular variability test. Among the 199 cotton genotypes screened, 50 genotypes showed moderate resistant, 69 genotypes showed moderate susceptible and 80 genotypes were found highly susceptible and among 14 commercial Bt cotton hybrids screened, nine hybrid were found moderately susceptible and the remaining five hybrids were highly susceptible to Alternaria leaf blight disease. In field evaluation of nine different fungicides, propineb (0.2%) showed better control of the disease with maximum yield. | en_US |
dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/87273 | |
dc.publisher | UAS, Dharwad | en_US |
dc.research.problem | Studies on Leaf Blight of Bt Cotton Caused by Alternaria spp. | en_US |
dc.sub | Plant Pathology | en_US |
dc.these.type | M.Sc | |
dc.title | Studies on Leaf Blight of Bt Cotton Caused by Alternaria spp. | en_US |
dc.type | Thesis | en_US |