S.S.AdiverK.B.Yadahalli2016-10-242016-10-242005http://krishikosh.egranth.ac.in/handle/1/81639Sett rot of sugarcane caused by Ceratocystis paradoxa (De Seynes) Moreau is becoming severe in recent years in major sugarcane growing areas of northern Karnataka. The disease survey (2003-04 and 2004-05) revealed maximum incidence of 18.78 per cent in Co-7804 around the Makanur village of Haveri district. In vitro studies conducted revealed that the pathogen (C. paradoxa) grew well and sporulated profusely on PDA. It preferred most the starch and potassium nitrate as carbon and nitrogen source, respectively for its growth and sporulation. It growth was high in temperature range of 25-30°C and at cent per cent relative humidity. Maximum growth was noticed when the pH of the media was between 6.0 and 7.5. In studies on inoculation methods, sett dip method was most effective, when the cut ends were dipped in suspension of germinated conidia. The culture filtrate of C. paradoxa found to be deleterious on tomato seeds, where germination of tomato seed which indirectly hints the production of toxin ethyl acetate (0.1 per cent) by the pathogen did not allow plumle emergence. Out of fifteen cultivars screened for disease reaction, none of the varieties showed resistance to sett rot. Based on the isozyme studies, isolates were categorized into three and four groups on peroxidase, polyphenol oxidase isozyme patterns, respectively. In the field experiment conducted during 2003-04 and 2004-05 in sick soils, sett treatment with carbendazim @ 0.1 per cent and T. harzianum @ 10 g/l along with soil application of FYM @ 25 t/ha and vermicompost @ 2.5 t/ha reduced the sett rot incidence (13.68%) significantly and improved the quantitative and qualitative yield and yield attributes with highest cost benefit ratio (1: 2.51).Plant PathologyThesis