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M. Sc. Dissertations

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20116
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Subject: Plant Pathology × End date: 2011 × Start date: 2011 × Thesis Type: M.Sc ×
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Now showing 1 - 6 of 6
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    ThesisItemOpen Access
    Influence of stripe disease [Drechslera graminea (Rabenh.) Shoemaker] on physio-biochemical parameters of barley and its management
    (CCSHAU, 2011) Satish Kumar; Karwasra, S.S.
    Stripe disease of barley caused by Drechslera graminea (Rabenh.) Shoemaker is a widely distributed disease in many barley grown parts of the world, but it has assumed more importance with the introduction of some new high yielding varieties. The present investigations were undertaken during 2007-08 and 2008-09 crop seasons with a view of elicit information on effect of disease on biochemical and physiological parameters particularly in vitro dry matter digestibility, protein content, malt extract, chlorophyll content, leaf area, photosynthesis, stomatal conductance and transpiration. Effect of disease on yield parameters, search for new sources of resistance, effect of sowing dates on disease incidence and efficacy of fungitoxicants in controlling the disease. In vitro dry matter digestibility (IVDMD) decreased and total protein (%) increased in barley plants having disease, while malt extract (%) was more in grains collected from healthy plants. Stripe infection resulted in reduction of all the physiological parameters at both the stages i.e. 35 days and 50 days after disease appearance. Stripe disease had also the adverse effect on all the growth and yield parameters. Maximum reduction was in tillers/plant i.e. 69.97% while the reduction in yield /plot (kg) was 29.03%. Six rowed barley lines/varieties when compared with two rowed barley lines/varieties on the basis of mean infection value, two rowed lines/varieties had more resistance than six rowed. Grouping on the basis of mean infection value in six rowed barley 3 lines / varieties were highly resistant, while in two rowed 4 lines / varieties were highly resistant. In early sown crop i.e. 15th October there was no disease but in late sowings there was disease. Soil moisture had the positive correlation with disease incidence with values 0.83 and 0.84. Five fungitoxicants evaluated were significantly effective in controlling the disease at 0.1 and 0.2 per cent doses. Raxil-2DS at lower dose (0.1%) was quite effective with 2.75% disease on plant and 1.08% tiller basis. However, Raxil-2DS and Vitavax-75WP at 0.2% were very effective and provided maximum disease control on plant and tiller basis. Maximum yield was also obtained in both the treatments.
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    ThesisItemOpen Access
    Epidemiology and management of anthracnose of chilli (Capsicum annuum) caused by Colletotrichum capsici (Syd.) Butler and Bisby
    (CCSHAU, 2011) Om Prakash; Khirbat, S.K.
    Studies on epidemiology and disease management through fungicides, bacterial antagonist as well as plant extract under field conditions were carried out with Colletotrichum capsici causing anthracnose of chilli. Pre and post inoculation moist period studies revealed that minimum post inoculation moist period for initiation of the disease was 12 hours with maximum infection at 72 hours. However, pre inoculation moist period resulted in increased infection but was not as effective as post inoculation moist period for disease development under screen house conditions. In host range studies, the pathogen was found to infect three Kharif crops (cotton, raddish and black gram) and four weeds (sawank, kagaroti, kharjal and mirch booti). Pseudomonas fluorescens (Ludhiana isolate) was effective in reducing the growth of pathogen in vitro conditions. In some plant extract studies, the marigold 50% was effective for reducing the growth of pathogen and gave 100 per cent spore germination inhibition in vitro conditions. In studies with fungicides, mancozeb and carbendazim at 0.2% concentration were much effective in reducing the die back incidence. In field studies against fruit rot of chili with fungicides, antagonist and plant extract revealed that mancozeb and carbendazim at 0.2% concentration were equally and significantly effective in reducing the fruit rot severity. However, Pseudomonas fluorescens (Ludhiana isolate) and marigold plant extract (50%) were not much effective in reducing the fruit rot severity. Out of ten chilli germplasm lines, NCH-1124 and LCA-301 were found to be moderately resistant to the disease. Biochemical studies indicated that the resistant varieties contain higher ascorbic acid content and less total sugar. While comparing the different stages of fruits, the red fruits of resistant varieties were having much higher ascorbic acid content and less total sugars as compared to green and turning red stages of chilli fruits.
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    ThesisItemOpen Access
    Studies on management of damping-off of cucumber (Cucumis sativus L.)
    (CCSHAU, 2011) Saroj; Gandh, S.K.
    The pathogen causing damping-off disease in cucumber was identified as a fungus, Rhizoctonia solani Kuhn. The pathogen caused both pre- and post-emergence damping-off of cucumber seedlings. It could incite more than 80 per cent disease incidence at inoculum level of 600 mg/kg soil. Amongst various bio-agents evaluated in in vitro conditions by dual culture technique, the fungal antagonists Trichoderma viride, Trichoderma harzianum checked the growth of Rhizoctonia solani between 67 and 78% while bacterial antagonist, Pseudomonas fluorescens inhibited the mycelial growth of the pathogen upto 49%. Cucumber seed coating with Trichoderma viride, Trichoderma harzianum and Pseudomonas fluorescens controlled damping-off to the extent of 55.5, 44.5 and 40.7%, respectively. Both Trichoderma viride and Trichoderma harzianum were also effective when applied in pathogen inoculated soil. Soil application of different manures/cakes viz., mustard cake, farm yard manure, poultry manure, mushroom-spent compost and neem cake reduced the damping-off of cucumber between 18 and 32%. In integrated disease management, seed treatment with captan (0.2%) plus soil application of Trichoderma viride (15g/kg soil) and neem cake (7.5g/kg soil) provided highest protection (67%) to cucumber seedlings against Rhizoctonia solani
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    ThesisItemOpen Access
    Studies on management of leaf crinkle disease in blackgram (Vigna mungo (L.) Hepper)
    (CCSHAU, 2011) Roopesh Kumar; Sangwan, M.S.
    Present investigation on “Studies on management of leaf crinkle disease in blackgram (Vigna mungo (L.) Hepper” was carried out in field condit ions. Disease incidence increased signi ficantly wi th delay in date of sowing. Di sease incidence in relation to weather variables revealed that maximum weekly increase was in 7th week after sowi ng during late sowing whereas it was in 8th week after sowi ng during normal and early sowing respectively. The stepwi se mul tiple regression analysis of data in relation to weather variables revealed that > 0.49 R2 value was recorded in normal and late sowing. The regression equations developed revealed that Temp. Min. (X2) played the major role in leaf crinkle development in all the dates of sowing except early date of sowi ng. Barium chloride was signi ficantly effective in inducing resistance to leaf crinkle an average of 17.9 per cent incidence whereas in control i t was 43.9 per cent providing 59.2 per cent disease cont rol. Riboflavin significant ly increased the height of leaf crinkle infected plant s. The plot s sprayed with Tween-80, significantly decreased disease incidence an average of 17.2 per cent as compared control providing 58.4 per cent di sease cont rol and significantly increased height and 1000 seed weight of leaf crinkle infected plant s. Leaf crinkle incidence decreased significant ly an average of 14.6 per cent sprayed wi th Bougainvi llea ext ract as compared to unsprayed plot s (control ) provoding an average of 67.4 per cent disease control. Bougainvi llea extract significant ly increased the height ; number of branches/plant and number of pods/plant and 1000 seed weight of leaf crinkle infected plants. Leaf cinkle incidence decreased significantly an average of 22.6 per cent sprayed wit h Dimethoate 30%EC (Two sprays) as compared to control, providing 24.5 per cent disease control. Dimethoate 30%EC (two sprays) significantly increased the height; number of branches/plant and number of pods/plant, rachis length and 1000 seed weight of di seased plants. Out of fifty test lines, twelve were found Resistant, sixteen lines as Moderately Resistant, fifteen lines as Susceptible and seven lines as Highly Susceptible.
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    ThesisItemOpen Access
    Studies on management of brown spot disease of rice (Oryza sativa L.) caused by Drechslera oryzae
    (CCSHAU, 2011) Satish Kumar; Dharam Singh
    Present investigation on “Studies on management of brown spot disease of rice (oryza sativa L.) caused byDrechslera oryzae” was carried out in field conditions.Drechslera oryzae was isolated from the leaf showing typical brown spot symptoms to carry out management studies. Survey of rice growing areas of Haryana was conducted at dough stage of crop to record incidence of brown spot disease. Maximum disease incidence was recorded in scented rice in the district of Karnal and Panipat. To identify source of resistance, a collection of 140 genotypes were evaluated for their reaction to Drechslera oryzaeunder artificial epiphytotic conditions. Out of 140 genotypes, only two viz., IR 79216-141-1-3-3, KJT-3-2-7-7-2 and four viz., HKR 08-63, OM 5240, OR 2329-22 and RP Bio-110 were found highly resistant and resistant respectively, which can be utilized in resistant breeding programme. The effectiveness of 9 fungicides and 7 botanicals were tested in in vitro against mycelial growth inhibition and as foliar spray to test against all the three phases of brown spot disease viz., leaf spot severity, stalk and neck rot incidence. Invitro growth inhibition test revealed that the fungicides and botanicals varied considerably in their toxicity to Drechslera oryzae. The EC50 values of fungicides ranged between 58.6 to 998.6 ppm a.i. Propiconazole was most inhibitory with EC50 value of 58.6 ppm a.i. closely followed by strobulin having EC50 value of 68.2 ppm a.i. Tebuconazole was least inhibitory with EC50 value of 998.6 ppm a.i. The EC50 values of botanicals ranged from 6327.2 to14590ppm a.i. Mentha was most inhibitory with EC50 value of 6327.2 ppm a.i. closely followed by Arjun tree with EC50 value of 6555.4 ppm a.i. Pipal leaves extract was least inhibitory with EC50 value of 14590 ppm a.i. Propiconazole also proved most effective in controlling all the three phases of brown spot disease and increasing grain yield followed by strobulin when applied as foliar spray.Tebuconazole proved least effective. Amongst botanicals, Arjun tree leaf extract proved most effective in controlling disease and increasing grain yield followed by Mentha and Achook.
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    ThesisItemOpen Access
    Studies on stem rot in groundnut (Arachis hypogaea L.) caused by sclerotium rolfsii Sacc.
    (CCSHAU, 2011) Syed, Ghouse Abid; Rathi, A.S.
    The present investigation was undertaken to find out losses in yield parameters, evaluation of germplasm lines against stem rot, effect of different pesticides and bio-agents on growth inhibition of S. rolfsii in vitro and effect botanicals on disease under screenhouse conditions in groundnut. Increase in disease severity of stem rot led to corresponding decrease in height per plant, number of pods per plant, shelling percentage, test weight and oil content in both the genotypes (MH 4 & MH 21). Reduction of 49.55-70.04 per cent in height and 79.26-98.02 per cent in pod number per plant was observed at 80-100 per cent disease severity. Shelling percentage and test weight were also found to be affected with the increase in disease. Reduction of 15.73-31.21 per cent in shelling percentage and 15.65-51.60 per cent in test weight was recorded at 80-100 per cent disease severity. Reduction in oil content of 6.90-15.97 per cent was recorded in plants having 80-100 per cent disease severity. Out of one hundred twenty eight germplasm lines of groundnut screened against stem rot disease in field under sick plot conditions, four lines viz., GC 31, GC 83, 115 and GC 131 showed moderately resistant reaction. Hexaconazole and carboxin completely inhibited mycelial growth at 10 ppm concentration followed by propiconazole at 50 ppm concentration, while chlorpyrifos and thiram completely inhibited at 500 and 1000 ppm, respectively. The herbicides viz., pendimethalin, imazethpyr and oxadiazon were not found effective and inhibited around 50 per cent of mycelial growth at higher concentration of 1000 ppm. Out of three bio-agents tested in vitro P. fluroscence inhibited the fungal mycelial growth up to 97.19 per cent followed by T. viride, which inhibited the mycelial growth up to 71.12 per cent. Soil application of hexaconazole solution @ 1% significantly controlled the disease by 49.09 and 52.74 per cent while, seed treatment with P. fluroscence significantly controlled the disease by 43.36 and 50.65 per cent in MH 4 and MH 21, respectively under screenhouse conditions. Among the botanicals, neem kernel powder @ 40 g/pot significantly controlled the disease by 49.94 and 59.91 per followed by 40.95 and 46.87 per cent due to mustard cake powder in genotypes MH 4 and MH 21, respectively.