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Birsa Agricultural University, Ranchi

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2013 - 201915
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Subject: Plant Pathology × End date: 2019 × Start date: 2013 × Type: Thesis ×
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    ThesisItemOpen Access
    VARIABILITY OF Rhizoctonia solani Kuhn INFECTING SMALL MILLETS AND THEIR MANAGEMENT
    (Birsa Agricultural University, Ranchi, 2019) Krishnaveni, Varala; Ekka, Savita
    Rhizoctonia solani Kuhn (Teleomorph: Thanatephorus cucumeris) is a soil borne, polyphagous, necrotrophic plant pathogenic fungus with a wide host range. It is causing sheath blight disease on a wide range of Graminae plant hosts and causes considerable losses in yield. The pathogen is genetically diverse showing variability in respect of cultural/ morphological and physiological characters. 100 isolates of Rhizoctonia solani were obtained from four different small millets showing typical symptoms of the disease. Among them, only 53 isolates were selected and designated based on their growth characterisics and respective host for intensive characterization. Studies on morphological character of different isolates of R. solani revealed that the variation with respect to hyphal width, distance between the septation and mycelial weight. Hyphal width of most of the isolates were having moderate to long width (5-10 μm). In foxtail millet isolates, distance between septation is more when compared to remaining isolates. Mycelial weight is maximum in finger millet isolates. Studies on cultural variability showed considerable variation among the isolates. The colony diameter is varied from 41.33-90 mm at 72 hrs of incubation. Majority of the isolates of foxtail millet and finger millet were slow growing whereas isolates of proso millet and little millet were fast and medium growing. The colony colour varied from white, light brown to brown. Concentric circle is present in most of the isolates of foxtail millet and finger millet and it is completely absent in proso millet and little millet isolates. Dispersion of mycelium varied from subdued to aerial growth. Studies on sclerotial bodies revealed that, sclerotial formation is absent in 12 isolates. Number of sclerotia per plate were varies from 11-138, in which foxtail millet isolates produced more number of sclerotia with minimum size and weight. Majority of the isolates have brown coloured sclerotia with round shape and smooth surface. In arrangement of sclerotia, foxtail millet and finger millet isolates showed greater variation with different patterns of arrangement viz., peripheral, central, central+peripheral, concentric circle or uniformly/scattered distributed. Studies on pathogenic variations revealed that variation observed in accordance with the latent period, lesion size and lesion shape. Cross inoculation studies revealed that most of the isolates of R. solani were cross infective with each other and all the proso millet isolates were highly pathogenic on foxtail millet. Host range studies unveiled that majority of the isolates successfully infect rice, sorghum, soybean, bajra except groundnut but their virulences on different crops were quite different. It was observed that slow growing isolates of foxtail millet, finger millet and little millet were more aggressive than medium and fast growing isolates. Sensitivity of fungicides against 12 isolates showed that at 0.1% conc. triazole fungicides (propiconazole, difenconazole and tebuconazole) completely inhibited the mycelial growth and sclerotial production. In further evaluation of triazole fungicides at 0.05% conc. propiconazole & tebuconazole showed significant inhibition in mycelial growth and sclerotia. Among the botanicals, clove extract of Allium sativum (Garlic) showed maximum mycelial growth inhibition. Bulb extract of Allium cepa (Onion) and rhizome extract of Zingiber officinale (Ginger) effectively reduced the sclerotial production. Among bio-control agents, Trichoderma harzianum (T. harzianum-H) procured from hyderabad showed maximum inhibition of mycelial growth whereas in field evaluation, soil application of value added Pseudomonas fluorescens + Trichoderma viride + Bacillus subtilis 335 g each of talc formulation mixed in 25 kg of FYM at the time of sowing recorded least banded sheath blight incidence of with highest grain yield in little millet and foxtail millet.
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    ThesisItemOpen Access
    VARIABILITY IN Fusarium oxysporum f.sp. udum CAUSING WILT OF PIGEON PEA AND ITS MANAGEMENT
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2018) Hareesh, Mudadla; Lal, H.C.
    The present investigation was carried out in the research farm as well as laboratory of Birsa Agricultural University, Kanke, Ranchi on variability in Fusarium oxysporum f.sp. udum causing wilt of Pigeonpea and its management. The systematic investigation revealed that wilt disease in Pigeonpea was found to be infected with Fusarium oxysporum f.sp. udum at all ten locations surveyed in 2015-16 and 2016-17. Maximum wilt percentage was found at Bukru (32.14 %) followed by Kanadu (29.40 %) and Ranchi BAU (28.63 %). After conducting elaborate survey at 10 locations, forty isolates were collected for studying variations among isolates characters. To identify Fusarium pathogen as it’s actual casual agent for the disease pathogenicity test was conducted by using different effective isolates (Isolate-1, 14, 35). It clearly revealed that Fusarium oxysporum f.sp. udum is the cause for wilt disease in Pigeonpea. Morphological studies of Fusarium oxysporum f.sp. udum revealed that the dimensions of macro condia, micro conidia and chlamydospores shows larger variations among different isolates. The cultural characters observed on PDA medium and the mycelium colour was in white and pinkish at the center with dense to fluffy growth. The size of mycelial width varied from 3 μm (Fou-Bor -4) to 6.32 μm (Fou – Ran - 4). Where as microconidia were small, oval in shape and hyaline in colour, unicellular or with one or two septa, and measures in the range of size between 6.00 × 2.10 μm (Fou-Ran- 4) to 10.80 × 3.00 μm (Fou- Kok-1). The macroconidia were long, curved, sickle shaped, pointed at the tip, hyaline in colour and knotched at the base, septated (2-4 septa) and measured between 19.05 × 3.25 μm (Fou- Hoc-4) to 28.70 × 2.50 μm (Fou- Kok-1). Chlamydospores with spherical in shape and hyaline in colour and it’s dimensions also varied in all 40 isolates of the pathogen. Chlamydospores dimension varied from 8.20 × 7.92 μm (Fou- Buk – 2) to 11.35 × 8.20 μm (Fou-Nag-3). Spore density also varied between conidia per ml of culture under 10 x microscopic field, it is varied for macro conidia in the range of 6 to 13, micro conidia it is between 20 to 42 and chlamydospores it is between 2 to 8 number per ml. Among all the four different semi solid media maximum radial growth 72.90 mm for Fou-Ran-1was observed on PDA medium. All forty isolates performed well on PDA medium compared with remaining ones. After their growth different spores counting was taken under 10x microscopic field. It was also observed that there is a great variation in sporulation among isolates on different media and conidial characteristics. Among four liquid media, maximum and fastest mycelial growth was obtained in PDA medium followed by Richards medium, Czapeks medium, & Martins medium. In PDA liquid media isolate Fou-Ran-1 given maximum mycelial dry weight that is 470 mg. After in detailed study of all forty isolates regarding their cultural, morphological studies these isolates are grouped into different categories based on criteria like size of macro and micro conidia, septation of macro condia, their growing speed on different semi solid mediums and number of spores under 10x microscopic field. Out of 19 medium entries most of them showed moderately resistant to wilt disease, in 43 late entries, 5 entries namely MA-6, PT0012(C), WRGE 102, CRG9701, WRGE 248 showed resistance against wilt disease, remaining most of varieties moderately resistant to wilt disease. In host differential reaction, ICP8868, BDN-2, BAHAR genotypes showed same reaction to the three different effective isolates (Isolate – 1, 14, 35), and these are grouped under variant 3 based on previous experiments results. In Fungicidal trail Saaf performed well against wilt disease both in lab and field conditions. In case of organic amendments (cakes) Neem+Mustard cake performed well in both lab and field conditions against wilt disease of Pigeonpea. In bioassay trial of bioagents against wilt disease of Pigeonpea Trichoderma viride performed well in both In-vitro and In-vivo conditions.
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    ThesisItemOpen Access
    EPIDEMIOLOGY AND MANAGEMENT OF FRUIT ROT DISEASE OF BRINJAL INCITED BY Phomopsis vexans
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2018) Kumar, Mithlesh; Ekka, Savita
    Brinjal (Solanum melongena L.) is an important vegetable crop which gives very high economic return to the growers. Fruit rot caused by Phomopsis vexans (Sacc. & Syd.) is one of the major constraints in its successful cultivation. During survey, the disease was prevalent in all area surveyed. The incidence of disease ranged from 18.33 to 62.00 per cent in different locations. Maximum incidence (62.0 %) was recorded in the cultivar Pusa Purple Long at Technology Park of Birsa Agricultural University, Kanke, Ranchi whereas least disease incidence (18.33 %) was recorded in cultivar Pratima at Nagri village of Kanke block. The pathogen affect all the aerial parts of plant and causing damping off seedling at nursery bed and leaf blight, stem blight and fruit rot symptoms at the main field. Fruit rot is the most destructive phage of disease resulted in formation of large rotten area on fruit and made it inedible and unmarketable. The pathogen was isolated and purified by following tissue isolation technique. Pathogenicity of the pathogen was proved by seed, soil, leaves and fruit inoculations. On the basis of cultural and morphological characteristic the pathogen was identified as Phomopsis vexans (Sacc. and Syd.). Correlation coefficient between disease (dependent variables) and weather variables (independent variables) showed that maximum temperature and maximum relative humidity were highly significant and positively correlated with disease intensity whereas minimum relative humidity was highly significant but negatively correlated with PDI. The rain fall was significant but negatively correlated. Multiple regression analysis between PDI and weather variables altogether accounted 97 per cent variation which was highly significant. Among the varieties/cultivars of brinjal screened against the disease, none of them was found to be resistant. Only two varieties, Ramnagar Giant and Round Green Katedar showed moderately resistant reaction. Out of six fungicides evaluated, Saaf (Carbendazim 12% + Mancozeb 63% WP) and Nativo (Tebuconazole 50% + Trifloxystorbin 25%) completely inhibited the mycelial growth of pathogen in -vitro. Among plant extract/botanicals crude leaf extract of Allamanda catheritica (pilikaner) completely inhibited the mycelial growth of pathogen. Under field condition, seed treatment with Saaf (Carbendazim 12% + Mancozeb 63% WP) @ 2g/kg seed + 2 foliar spray with Contaf (Hexaconazole) @ 0.1% managed the disease efficiently with minimum disease intensity (16.67 %) and highest fruit yield (264.53 q/ha) as compared to (44.33 %) disease intensity and (217.06) q/ha fruit yield in control. Seed treatment with Saaf @ 2g/kg seed + 2 foliar spray with Saaf was next effective treatment with highest per rupees return.
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    ThesisItemOpen Access
    STUDIES ON SMALL MILLETS ISOLATES OF Pyricularia grisea AND ITS ECO-FRIENDLY MANAGEMENT ON FINGER MILLET
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2018) Kumar Paswan, Avinash; Ekka, Savita
    India is the largest producer of many kinds of millets, which are often referred to as coarse cereals. They are now considered as “Nutria-cereals” (nutritious grains) owing to their high calcium, iron, fiber and other quality effects. These nutria-cereals are the important dry land crops comprising of finger millet (Eleusine coracana), kodo millet (Paspalum scrobiculatum), foxtail millet (Setaria italica), little millet (Panicum sumatrense), barnyard millet (Echinochloa frumentacea) and proso millet (Panicum miliaceum). Though the crop is less prone to diseases and pests but under vulnerable condition, blast caused by Pyricularia grisea (Cooke) Sacc. Telemorph of heterothallic ascomycetes, Magnaporthe grisea (Hebert) Barr. [Anamorph:] had wide host range of Gramineae and taken heavy toll of the crop in various ecological zones. 18 monoconidial isolates of P. grisea were obtained from four different Small millets sowing characteristic symptom on foliage. Among them, only four isolates were selected and designated as Pg1, Pg2, Pg3 and Pg4 based on their growth characteristics and respective host for intensive characterization. Studies on morphological character of different isolates of P. grisea revealed that the variation with respect to shape, colour, septation and size of conidiophores and conidia. The mycelia of the isolates were highly branched, septate, superficial and bearing conidia at the tip or side of the conidiophores. In all isolates, conidia were two septate, three celled with broad base and pointed apex having pyriform shape except Pg3 formed sub pyriform with slightly constrict apex. Among the isolates, the size of conidia was largest in Pg3. Studies on cultural variability of different isolates on four media (Potata dextrose agar, Corn meal agar, C’zapek Dox agar and Richardʼs agar media) showed considerable variations. Maximum radial growth of all isolates was obtained on PDA media and minimum on RA media. Colony colour of all isolates showed variation on different media. On PDA all isolates produced greyish white to milky white colony. On CMA media Pg1 and Pg4 isolate exhibited greyish black colony. On CDA media all isolates formed dull to buff white colony whereas, on RA media all isolates produced greyish buff white colonies. Colony texture of all isolates showed variation on different media recorded isolates on all media were raised, course to smooth with uniform, medium to poor growth Cross inoculation studies revealed that the isolate of finger millet (Pg1) and isolate of foxtail millet (Pg4) were found to be cross infective with each other whereas the isolate of proso millet (Pg3) and little millet (Pg2) were non-infective on other hosts. In-vitro efficiency of seven plant extracts were evaluated against P. grisea isolates at two 5% and 10% concentrations by poisoned food technique and the result indicated that Zuki (herbal control product) shows maximum mycelial growth inhibition among all plant extracts evatuated. Among bio-control agents other than botanicals, T. viride, inhibited the growth of finger millet isolate Pg1 and foxtail millet isolate Pg4 whereas, P. fluorescens recorded maximum inhibition on isolates of little millet Pg2 and isolate of proso millet Pg3 . Varietal screening through host plant resistance reaction revealed that out of 23 genotypes of finger millet only one genotype, VL352 recorded highly resistant reaction whereas, ten genotypes (GPU 94, VR 936, GPU 67, BR 14-3, GPU 93, KMR 630, GPU 48, VL 386, GPU 48, and VL379) showed resistant reaction against leaf neck and finger blast. Eco-friendly management through botanical and bio-control agents resulted that seed treatment with T. viride @ 4g/kg + 1st foliar spray with Zuki @ 0.1% + two foliar spray with P. fluorescens @ 0.6% recorded maximum diseases control 55.55 per cent and 61.42 per cent in neck blast and finger blast respectively, with highest grain yield 1530.87 kg/ha.
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    ThesisItemOpen Access
    STUDIES ON ROOT ROT (Rhizoctonia solani Kuhn) OF FRENCH BEAN
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2017) Kumar, Mithilesh; Kudada, N.
    Root rot caused by Rhizoctonia solani is a major devastating disease of French bean causing significant reduction of yield Considering the economic importance of the disease present investigation has been come out. The systematic investigation revealed that French been was found to be infected with root rot at all locations surveyed. Disease incidence varied from 13.4 to 35.8 percent and 14.4 to 32.2 percent during Rabi 2014-15 and 2015-16 cropping season, respectively. Morphological studies revealed that mycelium was monilioid thread and spider and web like on foliage or aerial parts and measured 4.8 μm to 9.4 μm in size. Sclerotia were globose to irregular, white to dark brown and measured 1.0 mm to 3.8 mm in size. Mycelium was at first hyaline but brownish at age and septate. Branching often at nearly acute or right angles in older hyphae. Mycelial suspension was found more conducive to disease incidence of root rot with shorter incubation period in comparison to sclrotial suspension. In dual culture maximum inhibition of mycelial growth was noticed in T. harzianum (56.36% and 64.91%) after 4 and 7 days incubation which was at par with T. viride (54.54% and 63.60%) and followed by P. fluorescence (35.83% and 58.36%). In-vitro Neem cake extract inhibited maximum (64.15 and 81.84 %) mycelial growth of R. solani at 5 percent concentration after 4 days and (66.48 and 64.97 percent) at 10 percent concentration after 7 days incubation followed by Mustard cake and Karanj cake Out of eight different plant extracts, Neem (Azadirachta indica) leaf extracts inhibited maximum mycelial growth (66.87% and 54.14%) of the pathogen followed by Bakain (Melia azadirachta) leaf extract (50.81% and 24.62%) at 10 percent concentration after 4 and 7 days incubation. At 20 percent concentration, Neem (Azadirachta indica) leaf extract recorded maximum inhibition of mycelial growth (98.17% and 74.58%) followed by Bakain (Melia azadirachta) leaf extract (77.32% and 67.22%) after 4 and 7 days incubation. In- vitro bioasay of different fungicides viz., Carbendazim, Vitavax, Contaf and Nativo were found to be most effective at all concentrations (viz., 0.025, 0.05 and 0.1%) which inhibited cent per cent growth of R. solani after 4 and 7 days incubation The early sown crop (29th September followed by 19th September and 9th October) was found maximum seed germination percentage and minimum preemergence root rot disease incidence percent and maximum green pod yield. Seed germination and green pod yield showed highly significant positive association with maximum and minimum temperature, but pre-and post-emergence showed highly significant negatively association with maximum and minimum temperature during both the years Rabi 2014-15 and 2015-16 cropping season. Seed treatment with Trichoderma viride @ 5.0 g/kg seed showed maximum seed germination (85.82%) and minimum pre- emergence (13.93%) and post- emergence (17.00%) root rot incidence and maximum yield (63.44 kg/ha). Correlation coefficient studies exihibited negative and highly significant association of pre- and post-emergence root rot disease incidence with green pod yield during both the years Rabi 2014-15 and 2015-16 cropping seasons. Among oil cakes tested, Neem Cake revealed maximum seed germination (88.06%), minimum pre- and post- emergence mortality (11.26% and 13.07%), and maximum green pod yield (64.44 q/ha). Multiple correlation coefficient showed positive and highly significant association of plant height, number of branches/plant, number of green pods/plant, pod length/pod and green pod weight/plant with green pod yield in both the years 2014-15 and 2015-16. Among the different soil drenching of plant extracts, maximum seed germination (89.53%) and green pod yield (68.0 q/ha), minimum mean post-emergence (13.70%) root rot incidence was found by soil dreanching of Neem leaf extract, But minimum preemergence was found by soil drenching of Bakain leaf extract. Correlation coefficient showed positive and highly significant association of plant height, number of branches/plant, number of green pods/plant, pod length and green pod weight/plant with green pod yield during 2014-15 and 2015-16. Among seed treatment with fungicides, maximum seed germination (89.89%), maximum green pod yield (72.16 q/ha), minimum mean pre- (10.11%) and post (11.92%) - emergence root rot incidence was observed by seed treatment with Carbendazim. Multiple correlation coefficient showed positive and highly significant association of plant height, number of branches/plant, number of green pods/plant, pod length and green pod weight/plant with green pod yield. Combination of soil application of mustard cake @ 10.0 q/ha plus soil application of FYM enriched with T. viride plus soil drenching with Carbendazim (0.1 %) recorded minimum pre-emergence (8.13 percent) and post-emergence (11.6 percent) root rot disease coupled with maximum yield (83.75 q/ha). Multiple correlation coefficient showed positively and highly significant association of plant height, number of branches/plant, number of green pods/plant, pod length and green pod weight/plant with green pod yield during 2014-15 and 2015-16 cropping seasons. Out of fourteen varieties/cultivars screened, the two cultivars, HAFB-2 and YCDI showed resistant reaction against the disease.
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    ThesisItemOpen Access
    STUDIES ON LEAF BLIGHT OF PIGEONPEA CAUSED BY Alternaria spp. AND ITS MANAGEMENT
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2017) Rani, Nidhika; Lal, H.C.
    Pigeonpea was earlier badly affected by wilt in Jharkhand and Alternaria leaf blight was considered minor one but in course of time the disease is assuming proportions in some pockets of Jharkhand. The present investigation was carried out with the study included survey, symptomatology, isolation and purification of fungus, pathogenicity test, morphological studies, evaluation of fungicides, bioagents, plant extract, integrated management and varietal screening against Alternaria leaf blight of pigeonpea. The systematic investigation revealed that Alternaria leaf blight was found to be infected with Alternaria spp. at all eleven locations surveyed and maximum disease incidence was recorded in research farm of R.A.C Kanke. It ranged from (0-30%). The pathogen was isolated from infected samples and identified as Alternaria alternata showing grey-brown appressed to velvety sometimes with a cottony centre, size of conidia was 38.02 x 7.12 μ with 2-4 transverse septa and 0-2 longitudinal septa and Alternaria tenuissima showed olivaceous to dark green, cottony to velvety, size of conidia was 76.5 x 6.12 μ with 2-6 transverse septa and 0-3 longitudinal septa. Out of six different fungicides tested in vitro, Tilt (Propiconazole) at all concentrations completely inhibited (100%) the mycelial growth against Alternaria spp.In biocontrol studies, rate of mycoparasitism was faster in Trichoderma viride (Pusa isolates) against Alternaria spp. followed by Trichoderma harzianum 1(Delhi isolates). Among all the botanicals evaluated against Alternaria spp. in vitro, Garlic clove extract at 10% was found most effective in reducing the mycelial growth followed by onion and Neem. Seed treatment and two foliar sprays of Propiconazole @ (0.1%) effectively controlled the disease incidence which recorded 13.33 per cent disease severity followed by SAAF @ (0.2%) which recorded 14.33 per cent disease severity. Field evaluation of bio-agents, seed treatment and two foliar sprays of Trichoderma harzianum 1 showed minimum disease intensity of 14.33 per cent followed by Trichoderma viride. In case of field evaluation of botanicals application of Garlic (clove) extract at 10% showed minimum disease intensity of 11.66 per cent followed by onion bulb extracts. The effort has also been made to integrate the plant products and bio-agents as ecofriendly component along with fungicides for the effective management of the disease. Seed treatment with SAAF @ 2g/kg of seed plus two foliar sprays with Tilt @ 0.1 per cent was found to be most efficacious treatment showing minimum disease intensity (10.66%) of Alternaria leaf blight disease and increasing grain yield of 1535.33 kg/ha. The yield attributing traits like Plant population (91.00), Plant height (182.8 cm), No. of primary branches/ plant (18.26), No. of secondary branches/ plant (27.76), No. of Pods/ Plant (184.66), No. of Seed/ pod (4.30), 100 seed weight (11.27 gm) and grain yield (1432.56) were significantly superior in case of propiconazole (0.1%) treatment plot followed by SAAF.
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    ThesisItemOpen Access
    OCCURRENCE AND MANAGEMENT OF CHILLI LEAF CURL DISEASE COMPLEX
    (Birsa Agricultural University, Ranchi, Jharkhand-6, 2017) Zeeshan, Naaserah; Kudada, N.
    Chilli leaf curl disease complex is a major important viral disease. The crop grown in Jharkhand usually suffers seriously from this disease. Considering the economic importance of the disease prersent investigation has been carried out. Causing significant reduction in yield roving survey to know the incidence of chilli leaf curl virus disease was undertaken in Chutia, Pithoria, Bukru, Boreya and Sukurhuttu villages of Ranchi district. The survey results clearly indicated that the incidence of disease varied from 24.55 to 75.53% depending on the season in which the crop was grown. Incidence was low during Rabi, 2015-16 (24.55 -32.27%) and high during Kharif, 2016 (55.42 -75.53 %). All the plants of chilli infected with chilli leaf curl disease complex causes vein clearing on young leaves at the early stages of infection upward curling of young and old leaves and stunting in most cases. Curling of fruits could be seen in mature plants. Leaf curl caused by mites shows downward curling of leaves, partial suppression of lamina near the petiolar end and a shiny bronze colour on the lower surface of the leaves. Emerging young leaves in infected plants become brittle narrow and thicker. Leaf curl due to thrips results upward curling of leaves and interveinal buckling. Irregular scrapping of epidermis could also be seen. In chilli, the most obvious symptoms caused by P. latus is progressive inward rolling of leaves in an inverted boatshaped manner and has a shiny, silvery lining on their ventral surface, rat tailing of leaf petiole and brittleness of foliage, buds are aborted and flowers distorted, shoots grow twisted and fruit may be mishappen and russeted. Among different insecticides three times soil application of Carbofuran 3G (30 Kg/ha) recorded minimum average disease incidence (19.26%) with the highest yield of (87.78 q/ha) and recorded maximum disease reduction over control (38.23 percent) during Rabi, 2015-16 cropping season. In Kharif season, effect of different insecticides on leaf curl disease incidence, fruit yield and yield attributing characters of chilli were very low in comparison to Rabi season with higher leaf curl incidence, lower fruit yield and cost benefit ratio. It was appearance from the evaluation of plant products/ botanical in full conditions that plant product effectively reduce the disease as compared to control. Two sprayings of neem seed kernel extract (NSKE) 5% was recorded to the most efficacious botanical in reducing disease incidence (23.45 percent) coupled with highest yield (64.45 q/ha). Application of NSKE 5% @ 5ml/lit was highly economical which recorded cost-benefit ratio of 1:17.13 and net returned of Rs. 1,5543/- which recorded highest net return /ha among all the plant products. The efficacy of integrated management on chilli leaf curl disease complex showed that minimum disease incidence (12.58%) was recorded in treatment-2 [One time soil application of Carbofuran 3G @ 30 Kg/ha + 2 spray of Imidacloprid @ 0.003%] with the highest disease reduction over control (61.12%)]. Among seven varieties screened against ChLCV, none of the varieties were found free of disease in both Rabi and Kharif seasons. Leaf curl incidence was highest during Kharif season than Rabi season in all varieties. The effect of varieties on yield attributing characters of chilli revealed that the variety Pusa Jwala showed maximum mean plant height (44.14 cm), mean no. of branches/plant (5.82) ,mean no. of fruits/plant (5.69) , mean length/fruit (6.90 cm), mean breadth/fruit (0.97 cm) and mean weight/plant (71.49 gm) in Rabi season as compared to Kharif season which has comparatively less mean plant height (35.89 cm), mean no. of branches/plant (5.48),mean no. of fruits/plant (4.75), mean length/fruit (5.65cm) , mean breadth/fruit (0.59 cm) and mean weight/plant (41.26gm).
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    ThesisItemOpen Access
    VARIABILITY AMONG THE ISOLATES OF Sclerotium rolfsii Sacc. FROM DIFFERENT HOST PLANTS
    (Birsa Agricultural University, Kanke, Ranchi, Jharkhand, 2013) lal, Nikita; Ekka, Savita
    Sclerotium rolfsii Sacc. is soil inhabitant, non-target, polyphagous and an ubiquitous facultative parasite. It is widely distributed in tropics, subtropics and also in warmer parts of temperate zone of the world. It has wide host range infecting cultivated crops viz., potato, groundnut, soybean, frenchbean, elephant foot yam, chickpea, sunflower, chilli, tomato, cotton, lucerne, wheat and onion etc. The pathogen S. rolfsii induces a variety of symptoms such as seed rots, seedling blight, collar rot, stem rot, wilt in different host plants. It preferentially infects on stem, but can also infect root, leaf, flower and fruit. In severely infected field, loss ranges from 10 to 25 per cent and sometimes, it reaches upto 80 per cent . Twenty-one isolates of S. rolfsii Sacc. obtained from Elephant foot yam, Groundnut, Frenchbean, Soybean, Potato and Chickpea plants from different locations of Ranchi and Hazaribag district of Jharkhand and are designated as EFY 1, EFY 2, EFY 3, EFY 4, EFY 5, EFY 6, EFY 7, EFY 8, EFY 9, EFY 10,GN 1, GN 2, GN 3, GN 4, GN 5, FB 1, FB 2, S 1, S 2, P and CP were taken for investigation on variability. Pathogenicity test resulted that the isolates were capable to infect their own host. Morphological character studied on potato dextrose agar media revealed considerable variation among the isolates. The colony diameter varied from 77.33-90mm at 72 hrs of incubation. The color of mycelium was extra white to off white. Concentric circle is present in twelve isolates and absent in rest of the isolates. Nine isolates exhibited fluffy texture and rest were of compact texture. Fan like growth were found in eight isolates. Variability in morphology of sclerotial bodies reported that number of sclerotia per plate were varies from 42-485. The color of sclerotia was light brown to dark brown. Size of sclerotia varied from 0.78-2.09 mm and they were round, spherical or irregular in shape. The weight of 10 sclerotial bodies were recorded between 3.16- 14.87 mg. Days of maturity of sclerotia varied from 14-22 days. Arrangement of sclerotia in the petriplate was peripheral, central or uniformly distributed. The present investigation reveals that isolates comprised significant variation in morphological and cultural traits of S. rolfsii indicating the presence of different strains of the pathogen. The cross inoculation studies on different host revealed that among the twenty one isolates of S. rolfsii the three isolate viz., P, CP, and EFY 6 were highly cross infective and pathogenic to all hosts. Isolates EFY 1 and EFY 2 were moderately cross infective and was pathogenic to five host and rest were less infective. On the basis of susceptibility of host plant, frenchbean, chickpea and groundnut were found to be highly susceptible, Potato was moderately susceptible and elephant foot yam and soybean were susceptible host. Among the pesticides, 2, 4-D completely inhibited the mycelial and sclerotial growth of S.rolfsii of all the isolates. Chlorpyriphos is the next effective pesticide followed by Paraquat, Carbofuran and Imidachloprid. Thiomethoxam was the least effective pesticides.
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    ThesisItemOpen Access
    OCCURRENCE AND MANAGEMENT OF COLLAR ROT DISEASE OF FRENCHBEAN CAUSED BY Sclerotium rolfsii Sacc.
    (Birsa Agricultural University, Kanke, Ranchi, Jharkhand, 2013) Kumar, Ashwini; Kudada, N.
    The study included survey and surveillance, symptomatology, isolation and purification of fungus, pathogenicity test, morphological studies, screening and evaluation of bioagents, plant extract, host resistant, effect of organic amendments and integrated management against collar rot. The systematic investigation revealed that frenchbean was found to be infected with S. rolfsii at all seven locations surveyed and maximum disease incidence was recorded in RAC farm (16.66 per cent). Morphological studies of the S. rolfsii revealed that its growth was fast in culture media. The colony appeared light white and the mycelium was aggregated, loose, dense, cottony and fan shaped in appearance and dispersion.The sclerotial size ranged from 0.62-1.82 mm while weight per sclerotia ranged from 0.3-1.15 mg. The colours were light brown to dark brown. Among non-systemic fungicides, Zineb, Propineb, Mancozeb and Kavach @ 0.1%, 0.2% and 0.3% concentration completely inhibited the growth of the pathogen. Among systemic fungicides, Propiconazole, Vitavax, Hexaconazole and Saff @ 0.025%, 0.05% and 0.1% concentration completely inhibited the growth of the pathogen. Among all the botanicals evaluated against collar rot pathogen in vitro, Pongamia pinnata at 10 per cent concentration was found most effective in reducing the mycelia growth followed by Azadirachta indica. In monoculture, Trichoderma harzianum (R1) and T. viride (D) produced 90 and 90 mm colony diameter on PDA medium after 72 hours of inoculation. Rate of mycoparasitism was faster in Trichoderma harzianum (D) against collar rot pathogen followed by T. harzianum (R1). In dual culture maximum inhibition of mycelial growth (25.66%) was recorded by T. viride (D) after 48 hrs while maximum inhibition of mycelial growth (41.69%) was obserbed in Trichoderma harzianum (D) after 72 hrs of inoculation. The only one variety, HAFB-2 showed resistant reaction against collar rot disease incidence with highest green pod yield 56.66 q/ha. Treatment having neem cake + karanj cake @ 5 + 5 q/ha provided 68.84% decrease in disease over control followed by neem cake @ 10 q/ha which gave 59.29% decrease in disease over control. The combination involving soil drenching with Carbendazim @ 0.1per cent plus soil application of FYM enriched with T. viride @ 2.5 Kg/ha showed minimum disease incidence (12.66 per cent) and gave highest green pod yield 76.25 q/ha.