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Birsa Agricultural University, Ranchi
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ThesisItem Open Access Studies On Colletotrichum Blight Of Bitter-Gourd(Birsa Agricultural University, Ranchi, 2001) Savita Ekka; S.C.DubeyBitter gourd (Momordica charantia Linn.) is an important annual cucurbitaceous vegetable growing widely in Jharkhand as well as in India. The crop was severely affected by a defoliating disease Colletotrichum blight caused by Colletotrichum capsici (Syd.) Butler and Bisby. Intensity of disease varied from 37.4 to 74.9 per cent in different locations of Ranchi. The characteristic blight symptom of the disease was observed on leaves and fruits. The pathogen was isolated, purified and proved pathogenic following standard techniques. Among the varieties/lines of bitter gourd screened against the disease, none of them was found to be resistant. Only one variety i.e. Creeper showed moderately resistant reaction against disease. All ten plant species belonging to five families were infected during host range studies. Disease appeared during second week of September in field and increased gradually upto maturity of the crop. Apparent infection rate was maximum on 10th October in the presence of 20.5-29.1°C and 19.9-29.6°C temperature, 69.0 88.5 per cent and 62.5-91.3 per cent relative humidity, 0.3-9.5 mm mean rainfall and 2-4 numbers of rainy days. Significant negative correlations were established between minimum temperature, maximum and minimum relative humidity, mean rainfall, rainy days and disease development. Stepwise multiple regression analysis clearly indicated that minimum relative humidity and numbers of rainy days significantly negatively contributing in the prediction of disease development and accounted for more than 89 and 84 per cent variation, respectively. Vitavax, Tilt and Thiram inhibited cent per cent growth of the pathogen in vitro. Rest fungicides in order of superiority were Topsin-M, Kitazin, Bavistin, Captaf, Benlate, Contaf, Indofil M-45, Blitox-50, Kavach and Ridomil. Vitavax (2g kg seed) and Topsin-M (2g kg seed) treated seeds gave maximum germination and elimination of seed borne infection, respectively. Under field condition, integration of seed treatment with Vitavax and spraying of Tilt (0.1%) managed the disease efficiently with minimum disease intensity and highest fruit yield. Seed treatment with Vitavax and spraying of Topsin-M (0.05%) was next effective treatment with highest per rupee return..ThesisItem Open Access Studies on Web blight of Winged Bean(Birsa Agricultural University, Ranchi, 2001) Mithilesh Kumar; K. K. RaiWinged bean (Psophocarpous tetragonolobus V.A.Parthasarathy) suffers from a very devastating disease web blight caused by Thanatephorus cucumeris (Frank.) Donk = Rhizoctonia solani Kühn which has been found to be limiting factor in production of winged bean in the Jharkhand. Typical web blight symptoms were observed on all the infected aerial parts of the plants. The pathogen was isolated, purified, identified and proved pathogenic. Disease was initiated from second week of September in field with maximum apparent infection rate and gradually increased. Significantly negative correlation was established in between weather factors and disease intensity during both years of experimentations. Multiple regression analysis equations showed that minimum temperature significantly (negative) contributing in the prediction of disease development and accounted for more than 80% variations. Only one cultivar namely EC-38955 showed moderately resistant reaction against pathogen in the field under artificially inoculated conditions. Vitavax, Bavistin, Blitox-50, Contaf, Tilt, Captaf and SAAF were found most effective fungicides as they completely inhibited the growth of the pathogen in vitro. The integration of fungicides and Gliocladium virens (Trichoderma virens) provided good protection to germinating seeds than the any one alone in laboratory condition. Seeds treated with G.virens (10° spores/ml/10g seed) + Vitavax (1 g kg) gave significantly maximum inhibition zone/area covered by antagonist around seed. treatment enhanced seed germination under field conditions. Soil application of G.virens multiplied on pulse bran-saw dust-tap water (3:1:4 w/w/v) along with seed treatment with G.virens + Vitavax provided highest seed germination. Seed treatment with G.virens + Vitavax along with spraying of Tilt gave minimum disease intensity and highest pod yield followed by seed treatment with spraying of Contaf.ThesisItem Open Access Studies on Alternaria Spp.Causing Leaf Blight in Cauliflower and Its Management in Chotanagpur Region(Birsa Agricultural University, Ranchi, 1999) Navin Kumar; K.K.RaiLeaf blight disease of cauliflower (Brassica oleracea var, botrytis L.) caused by Alternaria brassicae is a widespread disease in Bihar. Spots were small, circular measuring 2-5 mm which gradually enlarged upto 10-25 mm in diameter. These spots were lighter in colour but later on changed to dark brown. Conspicuous zonations or concentric rings were formed on almost all the fully developed spots. Alternaria brassicae: Conidia obclavate, muriform, bottle shaped, attenuated into a long conspicuous beak at the tip and slightly narrowed at the base. Conidiophores - simple, erect or ascending straight, sometimes flexuous, more or less cylindrical. Mycelium-short, compact, septate, branched, hyaline at first, later on turned light brown to olivaceous gray, inter and intracellular, 4.8 μ wide and 3.6 u in diameter. Alternaria brassicicola Conidia variable in shape, cylindrical to oblong, poorly developed beak, muriform, light olivaceous to dark olivaceous, in long chain of 6 to 8 spores Mycelium - short, compact, septate, branched, sometimes hyaline, olive gray to grayish black, inter and intracellular 4.2 µ in diameter. Conidiophore simple, erect or ascending straight, cylindrical, olivaceous, septate, 5-7.5 x 35-45 μ, conidia born terminally on conidiophore. Radial growth and biomass production was found significantly superior in Richards and potato dextrose compared to other media followed by leaf extract, Czapek's agar and glucose asparagine. Optimum temperature and pH for growth and sporulation of the fungus were found 25°C and 5.5, respectively. Sucrose 1% proved to be the best medium for germination whereas distilled water and rain water resulted the least percentage of germination of spores. The fungus produced significantly maximum amount of 423.3 mg dry mycelial mat and sporulation in the standard Richard's medium containing sucrose and followed by glucose, mannitol and maltose. Organic form of nitrogen as Urea and asparagine was found to be the best source of nitrogen as compared to inorganic source. Among the inorganic source the fungus had much more affinity with nitrate form of nitrogen as sodium nitrate and ammonium nitrate than ammoniacal form ie. Ammonium chloride. Thiamine was found to be the best vitamin for maximum mycelial mat production and sporulation. Bavistin was found most efficacious at 200 ppm whereas 'karanj and neem oil completely inhibited the growth at 10,000 ppm. In field condition also this fungicide was found significantly superior at 0.05% concentration. Spore germination of the fungus was completely suppressed at 75 ppm. KT 9, Pusa subhra, Improved Japanese, Pusa Katki, Aghani and Poosi varieties: of cauliflower were found moderately resistant to Alternaria leaf blight disease.ThesisItem Open Access Management of Major Diseases of Brinjal In Chotanagpur(Birsa Agricultural University, Ranchi, 1999) Sajjad Hussain; U.ChoudharyBrinjal or egg plant (Solanum melongena L.) is one of the most important vegetable crop cultivated in Chotanagpur region extensively throughout the year and is attacked by a number of pathogens, amongst which predominant appears to be bacterial wilt and fungal leaf spot. In view of increasing importrance of bacterial wilt of brinjal caused by Ralstonia (Pseudomonas) solanacearum Smith and leaf spot caused by Alternaria alternata in Chotanagpur region, the management aspects of these diseases were proposed. Wilt intensities in different localities of Chotanagpur region varied between 10.0 to 64.8 per cent whereas leaf spot intensities in different localities varied between 5.2 to 17.6 per cent. The first sign of wilt disease appears as the loss in turgidity of leaves, withering and then drying of top leaves followed by lower leaves. In advance stages the entire plants are wilted. The leaf spot sign on leaves first appeared at the tip margins small light brown necrotic spot of pin head size. These spots gradually enlarged in size and other remained circular or assumed irregular shape became dark brown to grey in colour and defoliation of leaves also occured. The spots are first appeared on the lower leaves on later spreading upwards. Morphological studies confirmed that the bacterium was short, rod shaped motile, non-capsulated and gram negative whereas the fungal was with black, long acropetal chains conidia, septate dark mycellium, conidiophores single or in group with septation." In cultural studies, Tetrazolium chloride proved to be the best for excellent growth of the bacterium pathogen whereas for fungus the best media was Potato dextrose agar. Wilt incidence was favoured by high temperatures accompanied by high relative humidity during the crop period. In nature incidence of leaf spot disease increased gradually is the age of plants increased. Amongst the 15 varieties tested against the both pathogen (Bacteria and Fungus) only 3 varieties namely SM 6. KT 4, Punjab barasati were found to be resistant to wilt and leaf spot.ThesisItem Open Access Management of Major Chilli Diseases in Chotanagpur(Birsa Agricultural University, Ranchi, 1997) Navaljit Kaur; S. M. PrasadChhilli 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.ThesisItem Open 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.DubeyBroad 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).ThesisItem Open Access Studies Of Blight Of Marigold (Alternaria Tenuissima )(Birsa Agricultural University, Ranchi, 1997) Manoj Kumar Barnwal; D.K. JhaMarigold (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.ThesisItem Open Access Management of Major Tomato Diseases in Chotanagpur(Birsa Agricultural University, Ranchi`, 1997) Susmita Shrivastava; Dr. S. M. PrasadTomato (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.ThesisItem Open Access Studies On Collar Rot Of Okra Caused By Macrophomina Phaseolina( Tassi) goid(Birsa Agricultural University, Ranchi, 1996) Ajit Kumar Jha; S.C.DubeyOkra (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.
