Browsing by Author "Basanti Oraon"
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ThesisItem Open Access Investigation on Leaf Spot of Soybean (Glycine mas (L) Merril) Caused By cercospora sojina In Chotanagpur (Bihar)(Birsa Agricultural University, Ranchi, 1996) Basanti Oraon; B.MishraSoybean (Glycine max (L.) Morril) suffers from leaf spot disease caused by Cercospora sojina. The characteristic symptom was observed on leaf, atom, petioles and pads as also in seeds. The pathogen has been described in detail which appears to be a now host record in the plateau region of Bihar. It causes on appreciable damage (incidence 4.96-9.67 per cent) and severity (12.0 to 38.50 per cent) in and around Ranchi. In cultural studies, the radial growth and sporulation was best in Potato dextrose agar as well in Potato dextrose broth. However, the later gave excellent sporulation. The growth and sporulation were maximum at 28.1°C and pit 6.0 and thus were optimum temperature and pit, respectively. Glucose and Calcium nitrate were best sources of carbon and Nitrogen, respectively for maximum growth and sporulation. The diseased plant debris and diseased seed cause 16-65 per cent infection in the crop. The diseases was more severe with the environmental variables viz; reinfell (18.6 mm), relative humidity (71.7 %) and temperature (23.7°c) in Kanke conditions. In management trials, Drago variety of soybean proved to be moderately resistant against the pathogen. The pathogen could be effectively controlled with savistin (0.05 per cent) and Captor (0.2 per cent). In bio control, leaf extract of Argemon maxicana (20 per cent) inhibited maximum growth and sporulation of the pathogen.ThesisItem Open Access Studies on Major Fungal Diseases of Soybean Occurring in Chotanagpur Region of Bihar(Birsa Agricultural University, Ranchi, 2001) Basanti Oraon; K.K. RaiSoybean (Glycine max (L) Merril) in an important oil seed crop belongs to the family Leguminosae. It is cultivated through out the world chiefly for oil seed and pulses, Is highly nutritious, and contains high percentage of proteins, carbohydrates and vitamins. It has originated from China and was introduced in Madhya Pradesh during the year 1882. At present, the crop has occupied fifth position on world map of soybean. It is being grown in 4.2 milion hactare with a production of about 7,300 Lakh tons in India The crop is vulnerable to a number of diseases. Amongst these, Alternaria leaf blight caused by A. tenuissima, (Kunze Ex Pers.) wiltshire, Pod blight caused by C. glycines Hori and Rhizoctonia aerial blight caused by R. solani Kuehn are most destructive diseases of Soybean in the Chotanagpur region of Bihar. The crop was found to be severely affected by the above Pathogens which caused considerable losses in the production of Soybean in Chotanagpur Plateau of Bihar. The intensities of diseases ranged from 14.33 to 40.33 per cent in different localities in and around Ranchi. The characteristic symptom of the diseases caused by A. tenuissima, C. Glycines and R. solani were observed on leaves, petioles, stems and pods. The Pathogens were isolated, purified, and Koch's postulate tests were satisfied. Potato dextrose agar was found to be the best medium for growth and sporulation of A. tenuissima, and also growth and sclerotia formation in R. solani whereas Richards' agar supported the best growth and sporulation of C. Glycins. Amongst liquid media, Richards' medium was best for the growth and sporulation and sclerotia formation of A. tenuissima, and R. solani, respectively. However, C. Glycines gave best growth & sporulation on Potato dextrose broth also. pH 6.5 and temperature 25° C were found to be best for growth and sporulation/ sclerotia formation of all the Pathogens. Sucrose and Potassium nitrate were found to be the best sources of carbon and nitrogen, respectively for A. tenuissima, sucrose and calcium nitrate for C. glycines and maltose and potassium nitrate for R. solani. Maximum growth of all the three Pathogens was noted in Alternate light and darkness followed by continuous darkness and light. Seventyfive, ninety and thirty days old plants were highly susceptible to Allternaria leaf blight, pod blight and Rizoctonia blight, respectively. Alternaria leaf blight development was maximum during September with an average temperature of 22.5°C, R.H. 86 per cent, Total Rainfall 11.0mm. and maximum Pod blight development concided with an average temperature of 23.5°C, R.H. 71.5 per cent and Total Rainfall 4.9mm, during the month of October, whereas maximum Rizoctonia aerial blight disease development was in the month of August with an average temperature of 27.0°C, R.H. 86.1 per cent and total Rainfall 26.4mm. Amongst cultivars of Soybean screened only six varitivers viz., Birsa Soybean, JS-80-21, Bragg, NRC-32, DS-93-40-8, and MAUS-41 were found to be moderately resistant against all the three diseases evaluated. However, complete. resistance could not be shown by any one. and Fluchloralin was found to be best weedicide in suppressing the diseases of Soybean followed by oxyflourfen, Metachlor and Alachlor in suppressing the disease under studies. In management of diseases, Indofil M-45 (0.25 per cent) was found to be the best fungicide against Alternaria blight and Bavistin (0.05 per cent) for Pod blight and Bavistin (0.05 per cent) and Indofil M-45 (0.25 per cent) for Rhizoctonia aerial blight. These fungicides may be utilized by the farmers of the region for the control of respective diseases.