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Birsa Agricultural University, Ranchi
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ThesisItem Open 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.ThesisItem Open Access EPIDEMIOLOGY AND MANAGEMENT OF FRUIT ROT DISEASE OF BRINJAL INCITED BY Phomopsis vexans(Birsa Agricultural University, Ranchi, Jharkhand-6, 2018) Kumar, Mithlesh; Ekka, SavitaBrinjal (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.ThesisItem Open 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, SavitaIndia 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.