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Birsa Agricultural University, Ranchi

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1993 - 199715
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Subject: Mycology and Plant Pathology × End date: 1997 × Start date: 1993 × Type: Thesis ×
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Now showing 1 - 9 of 15
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    ThesisItemOpen Access
    Management of Major Chilli Diseases in Chotanagpur
    (Birsa Agricultural University, Ranchi, 1997) Navaljit Kaur; S. M. Prasad
    Chhilli is the most important solanaceous cash crop grown in Chotanagpur region. Its cultivation is severely affected by a number of diseases . In present studies , survey carried out during Kharif and Rabo 1995-96 indicated higher incidence of diseases during Kharif season. The incidence of die- back was recorded from 8.25 to 26.12 percent during season . Wilt incidence was recorded from 16.50 to 29.10 [ervemt diromg Rano season and 25.75 to 40.50 percent during kharif Season. The incidence of leaf curl was recorded to be 9.25 to 14.67 percent during Rabi season and 12.50 to 22.75 percent during kharif Season.
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    ThesisItemOpen Access
    Epidemiology And Management of Leaf Blight of Broad Bean (vicia Faba L.) Caused By Alternaria Alternata (fr.) Keissler
    (Birsa Agricultural University, Ranchi, 1997) Brajesh Patel; Dr.S.C.Dubey
    Broad Bean (Vicia faba L.) is an important pulse crop gown in India and abroad. In plateau region of Bihar, it is grown specially for vegetable purposes. During survey, it was found to be severely Infected with blight caused by Alternaria alternata (Fr.) Keissler. Disease incidence and intensity varied from 18.7 to 55.3 per cent and 16.8 to 58.2 per cent, respectively in different localities of Ranchi and other districts of Bihar. Symptoms appeared as circular to irregular necrotic lesions from the tip or margin of leaves. These lesions gradually increased or coalesce and become enlarged, dark brown to gray in colour with indistinct zonations and abundant sporulation. In dry weather, the necrotic tissues crack and become ragged. The brown infected leaves wither and de follate. Dark brown to black, circular to irregular lesions also appear on stem and pods. The pathogen was isolated on potato dextrose agar medium and pathogenicity was proved followed by Koch's postulates. On the basis of the morphological characters of mycelium and conidia produced in nature as well as in culture the pathogen was identified as Alternaria alternata (Fr.) Keissler. Six different solid and liquid media were evaluated for the mycelial growth and conidial production of the pathogen. Potato dextrose agar supported maximum growth (94.3 mm) and excellent sporulation of the pathogen followed by Richards' (86.7 mm) and Sabouraud's agar (82.3mm).
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    ThesisItemOpen Access
    Studies Of Blight Of Marigold (Alternaria Tenuissima )
    (Birsa Agricultural University, Ranchi, 1997) Manoj Kumar Barnwal; D.K. Jha
    Marigold (Tagetes spp.) suffers from Blight caused by Alternaria tenuissima (Kunze) Wiltshire. The incidence and intensity of disease varied from 24.67 to 57.33 and 27.13 to 52.47 per cent, respectively depending on the different localities. Leaves, stems and flowers were found to be infected and showed characteristic symptoms of the disease. The pathogen was isolated and purified by single spore method. Koch's postulate tests were done as also the pathogen has been described in detail. Which appears to be a new host record in Chotanagpur region of Bihar. In cultural studies, the best radial growth and good sporulation of the pathogen were observed on PDA among solid media and Richards media among liquid media. Fifteen plant species belonging to nine families were evaluated during host range studies of these, only three plants viz; Gram, Pigeonpea and Salvia were infected. The maximum disease intensity appeared on 21 days old Marigold plants sown on 6th October, 1995 and 12th October, 1996, respectively. Late sowing favoured disease development. 10.05 to 26.39°C temperature, 30.23 to 87.23 per cent relative humidity and 0.00 to 13.0 mm average total rainfall favoured maximum disease development of the crop in both the year.
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    ThesisItemOpen Access
    Management of Major Tomato Diseases in Chotanagpur
    (Birsa Agricultural University, Ranchi`, 1997) Susmita Shrivastava; Dr. S. M. Prasad
    Tomato (Lycopersicon esculentum Mill.) is the most common and important vegetable grown in Chotanagpur region. The productivity and the yield is deplorably low due to many constraints, particularly diseases. Survey carried out during Kharif and Rabi 1995-96 indicated higher incidence of diseases in Kharif. On an average 51.5 and 41.8 percent incidence of wilt was recorded during Kharif and Rabi, respectively, for the variety Pusa Ruby, whereas, it was comparatively less for other varieties viz; Punjab Chuhara. and Punjab Kesari. Incidence of leaf curl was recorded to be to 18.5 percent and 7.4 to 15.22 percent during Kharif and Rabi seasons as above, respectively. Alternaria leaf spot (Alternaria solani and A. alternata) was also found to be maximum during Kharit. In screening trial, tomato varieties BWR-5, Punjab Chuhara and LE-79 showed resistant reaction against wilt. As regards the reaction of different varieties to Alternaria leaf Blight, the varieties, BWR-1 and LE-79 showed highly resistant reaction. Tomato varieties, BWR-1 and JC-1 remained free from leaf curl disease. It may be mentioned that the overall leaf curl disease pressure was quite low. Fungicidal field trial against Alternaria leaf blight were undertaken using two early fungicidal sprays. Best results in controlling the disease was obtained from the spray schedule in which first spray was given with Indofil M-45 (0.2%) followed by a sec ond spray of Blitox-50 (0.2%) which recorded a minimum disease intensity of 33.60%. The next best treatment was the one in which two sprays of Indofil M-45 were given. This schedule also accounted for the highest benefit-cost ratio. The trial on seed treatment against tomato wilt revealed that all treatments could reduce percent wilt incidence. However, a combination of Streptomycin + Bavistin in the ratio 1:1 @ 0.5 gm each was found to be the best treatment followed by the combination of Streptomycin + Thiram in the same ratio and dose.
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    ThesisItemOpen Access
    Studies On Collar Rot Of Okra Caused By Macrophomina Phaseolina( Tassi) goid
    (Birsa Agricultural University, Ranchi, 1996) Ajit Kumar Jha; S.C.Dubey
    Okra (Abelmoschus esculentus (L.) Moench) suffers from collar rot a very destructive disease caused by Macrophonina phaseolina (Tassi) Gold (Rhizoctonia bataticola (Taub.) Briton-Jones). Disease incidence varied from 12.7 to 58.3% in different localities of Ranchi. The characteristic symptom of the disease was observed on both root and collar region of seedlings as well as adult plants. The pathogen was isolated, Purified and identified by standard method. The pathogen satisfied koch's postulate tests. Potato dextrose agar (solid) and Richards' (liquid) media supported maximum mycelial growth and sclerotial production. 6.5 pH was found to be optimum for mycelial growth and sclerotial production in Richards liquid medium. All 13 plant species belonging to 6 families were infected during host range studies. 21 days old plant were highly susceptible to infection and older plants showed resistance to infection. High temperature, low rainfall and low humidity were favourable for disease development. Significantly negative correlations were established in between disease incidence and age of plants, average temperature, average relative humidity and rainfall. However, the disease incidence was positively correlated with average relative humidity and rainfall during 1995 only. Late sowing minimized the disease development and gave good yield. In general, low disease incidence and higher yield were recorded during rainy season sown crop than summer season sown crop. Okra varieties, Supriya (F), and Arka Anamika showed moderately resistant and tolerant reaction, respectively against disease. The local isolate of Trichoderma viride showed maximum inhibition of mycelial growth of pathogen followed by T. harzianus (local isolate) and T. viride (Pantnager isolate) in vitro. All six isolates of three fungal antagonists inhibited cent per cent sclerotial production. Nature of mycoparasition was established. Among different plant extracts, Bhangria leaf extract showed maximum inhibition of mycelial growth (32.6%) followed by Marigold (29.1%) and Karanj (26.1%) leaf extracts at 5 per cent concentration. Whereas at 10 percant concentration, Bharbhand leaf extract showed maximum inhibition of mycelial growth (45.0%) followed by Bhangria" (39.0%) and Marigold (34.4%) leaf extracts.
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    ThesisItemOpen Access
    Investigations on Epidemiology and Management of Blast Disease of Ragi Eleusine Coracana Gaerin, Cased By Dyricularia Grisea Sacc
    (Birsa Agricultural University, Ranchi, 1995) Md. Reyaz Ahmad; U. Gupta
    Ragi blast, etiologically associated with the fungal pathogen, (Pyricularia grisea (Cke) Sacc.) is the most rigorous allment in Chotanagpur plateau region of Bihar. In view of its increasing importance, studies this very on epidemiology and management were carried out. disease emphasizing The morphological characters of P. grisea were studied both from nature as well as culture and has been described in detail. The congenial temperature (28 C) was found to be the best for growth and sporulation of P. grisea and grew best on Host leaf extract agar and Richards' solution at pH 7.0 but sporulation was found to be the best on Oat meal agar and Glucose-Peptone medium. Glucose and Peptone were found to be the best sources of carbon and nitrogen whereas any fluctuation in the C/N ratio other than 1:1 caused reduction in growth and sporulation. Conidia germinated well at 28 C and between pH 5 to 7. Maximum perpetuation period of the pathogen was recorded to be four months in Infested fingers at 2.5 cm soil depth. And, it was observed to perennate on a number of weed hosts growing in and around ragi field. Of these wild Eleusine and wild Panicum were found to be the most important collateral hosts. The most susceptible age of the ragi plants against P. grisea was found to be 60 days with respect to disease development.
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    ThesisItemOpen Access
    Studies on Epidemiology and Control of Chickpea Wilt Cased By Jusarium Oxysporum in Plateau Region of Bihar
    (Birsa Agricultural University, Ranchi, 1995) Divesh Kumar Singh; D. K. Jha
    Wilt of chickpea caused by Fusarium oxysporum f.sp. ciceri is one of the most important disease in chickpea growing area and it is responsible for heavy reduction in plant stand and yield. The affected seedlings show dropping of the leaves and paler colour than the healthy seedlings. They collapse and lie flat on the ground. The initial symptom of adult plants is dropping of petiols and rachis along with leaflets. Within 2 to 3 days dropping is seen on the entire plant. There is a show fading of the green colour and the plant looks dull green. Gradually all leaves turn yellow and straw-coloured. The disease plants are easily pulled out from the soil than the healthy ones. The affected plant show internal discolouration of the pith and xylem. The macro and micro-conidia and chlamydospores are produced by the pathogen in the host as well as in culture. Isolated fungus proved its pathogenicity during Koch's postulates test. Patato dextrose agar and Richards liquid medium proved to be the best. for excellent growth and sporulation of the pathogen. h The fungus could utilize all the tested carbon compounds for its growth and sporulation but mannitol proved to be the best. Among nitrogen sources, sodium nitrate wis excellent for growth and sporulation. Amongst the micro nutrients, the mixture of zinc. with iron was fungus in-vitro. found excellent for growth and sporulation of the The pathogen had a wide host range and was associated internally with the roots of pigeonpea, blackgram, greengram, linseed, lentil, pea, mustard and common weed present in chickpea field without expressing wilt symptoms, but not from sorghum, soybean, wheat and mize. The earlier wilting caused more loss than late wilting. The per cent loss in seed weight per plant at flower and podding stage, full podding stage and pre harvest stage were 95.81, 72.32. 39.70 per cent respectively. Out of 149 entries screened, only six entries viz: H 82-2, GL-87123, GL-90104, GNG-920, PCS-2 and RSG-538 were proved resistant to wilt. Late and deep sowing, soil solarization and intercrops with wheat, lentil, safflower and linseed reduced disease. incidence but plant population and different levels of fertilizers could not. reduce the disease incidence. All the tested oil cakes @ 25 q/ha increased the germination percentage of seeds, while neem cake not only increased the germination but also reduced the incidence of wilt. In biological control, Trichoderma viride and Gliocladium virens showed strong antagonestic action against pathogen in-vitro as well as in-vivo. They reduced the incidence of wilt when used as seed treatment and soil drenching. Thiram and Bavistin proved to be the most suitable fungicide in-vitro and minimized the disease incidence and increased the grain yield under field conditions. but maximum economic turn-over of Rs. 5.27 from an investment of Rs. 1.00 was obtained from two times drenching with Blitox-50 (0.3 per cent) during fungicidal control of the chickpea wilt.
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    ThesisItemOpen 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.Mishra
    Soybean (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.
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    ThesisItemOpen Access
    Studies on Fusarium Wilt Of Linseed (Linum usitatissimum L.) In Chotanagpur Region (Bihar)
    (Birsa Agricultural University, Ranchi, 1995) Mithilesh Kumar; U.Choudhary