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Theses

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2004 - 200926
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Subject: Plant Pathology × End date: 2009 × Start date: 2004 × Type: Thesis × Thesis Type: Ph.D ×
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Now showing 1 - 9 of 26
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    ThesisItemOpen Access
    Diseases spectrum and population dynamics of fluorescent pseudomonads and Trichoderma spp. during a conversion from conventional to organic farming system
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-01) Bipin Chandra; Basant Ram
    Increasing consciousness about conservation of environment as well as health hazards associated with agrochemicals and consumers• preference to safe and hazard free food are the major factors that lead to the growing interest in alternate forms of agriculture in the world. Organic agriculture is one among the broad spectrum of production methods that are supportive of the environment. Although it is by no means certain in which direction conventional farming systems will change, but organic farming practices will certainly change the cropping pattern, disease spectrum, use of synthetic fertilizers and pesticides and soil microflora. However these effects will need to be verified in comparative studies of different agriculture systems on conventional and alternative farms. Realization of this potential will depend upon a quantum increase in knowledge of microbial ecology particularly in rhizosphere. In the present investigations, on field comparative studies of organic farming, integrated farming and conventional farming treatments was conducted to assess the changes in disease spectrum in crops belonging to rice based cropping systems (rice, wheat, lentil, vegetable pea and mustard) under three farming systems and lab experiments were carried out in 2005-06 and 2006-07to observe population dynamics of soil antagonists especially Trichoderma spp. and Fluorescent pseudomonads under different farming and cropping systems regime. During both years sheath blight of rice, lentil rust, wheat rust and pea rust and in 2006-07 bacterial leaf blight of rice and pea powdery mildew were less severe in organic fields than in conventional fields despite fungicidal applications in the conventional fields. In 2005-06 leaf blight of rice and powdery mildew of pea were often similar in different farming trials but in subsequent year all farming treatments were significantly different. The only foliar disease that was more severe in organic fields during both consecutive years was brown spot in rice. Rhizosphere population of Fluorescent pseudomonads (fPs) and Trichoderma spp. had always been higher than from its counterpart non-rhizosphere in every crop used for study. Population of Fluorescent pseudomonads and Trichoderma spp. in nonrhizosphere were far low and fluctuated. During both consecutive years interaction between farming treatments and cropping systems was non-significant. Population dynamics of Fluorescent pseudomonads was far fluctuating in first year when evaluated in different farming treatments irrespective of cropping systems. Under integrated and organic treatments population of fPs was similar at early growth stage, but at 30 DAS and 60 DAS organic and integrated treatments supported higher population than conventional treatments. At 90DAS once again all three treatments exhibited no difference in population counts of fPs indicating inconsistence and unpredictable performance of farming treatments. In 2006-07 during the entire crop season at all the four growth stages of crop organic farming treatments exhibited maximum counts of fPs followed by integrated and conventional treatment. In rabi season of 2005-06 population counts of Fluorescent pseudomonads was maximum in rice-mustard cropping system at all the four growth stages, while in 2006-07 rice ²Vegetable pea cropping system supported maximum population of fPs. During both years, in rabi season at 15 DAS all the treatments were similar in terms of population counts of Trichoderma spp. and rhizosphere effect while at 30 DAS, 60 DAS and 90 DAS organic farming treatments supported maximum population counts of Trichoderma spp. and Rhizosphere effect. During both years in rabi season rice ²wheat cropping system supported maximum rhizosphere effect and population counts of Trichoderma spp. In rice crop of 2005-06 (Kharif season) all three farming treatments namely organic, integrated and conventional were similar regarding rhizosphere effect of Fluorescent pseudomonads. During both the Kharif seasons under study rice plots which were previously under vegetable pea supported maximum population of Fluorescent pseudomonads and also exhibited maximum rhizosphere effect irrespective of different farming systems. During both the rabi seasons wheat, lentil, vegetable pea and mustard were sown when followed by rice there was a gradual increase in rhizosphere population of fPs and Trichoderma spp. Under rice based cropping systems increasing trend was noticeable upto 60 DAS and thereafter a decline in population of fPs and Trichoderma spp. was observed. During both the Kharif seasons when rice is grown as a sole crop followed by wheat, lentil, vegetable pea and mustard, population of Trichoderma spp. studied showed gradual decline in population and rhizosphere effect.
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    ThesisItemOpen Access
    Cultural, Morphological, Molecular And Pathogenic Characterization Of Trichoderma Isolates From Tarai Area Of Uttaranchal
    (Govind Ballabh Pant University of Agriculture and Technology;Pantnagar, 2005) Joshi, Deeksha; Singh, U.S.
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    ThesisItemOpen Access
    Bio-prospecting for management of major pathogenic fungi of Agaricus Bisporus (Lange) Imbach
    (G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), 2004) Mishra, S.K.; Singh, R.P.
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    ThesisItemOpen Access
    Studies on wheat disease problems in rice-wheat system in the tarai region of Uttaranchal
    (G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), 2004) Joshi, Swati; Tawari, A.N.
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    ThesisItemOpen Access
    Studies On Microbiological Properties Of Some Biodynamic Preparations With Special Reference To Biocontrol Potential Of Some Microflora
    (Govind Ballabh Pant University of Agriculture and Technology;Pantnagar, 2004) Bijendra Kumar; Vishwakarma, S.N.
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    ThesisItemOpen Access
    Integrated manaagement of loose smut of wheat evaluation of genotypes for resistance and effect of some pesticides bioagent and botanicals
    (G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), 2005) Deepshikha; Tewari, A.N.
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    ThesisItemOpen Access
    Studies On Etiology And Management Of Mango (Mangifera Indica L.) Malformation Disease
    (Govind Ballabh Pant University of Agriculture and Technology;Pantnagar, 2004) Singh, Virendra; Singh, U.S.
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    ThesisItemOpen Access
    Studies On Bacterial With Potato Caused Ralstonia Solanacearum (Smith) Yabuuchi Et Al.
    (G.B.Pant University Of Agriculture And Technology Pantnagar : Uttaranchal, 2004) Khan, Rashid Mohammad; Pundhir,V.S.
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    ThesisItemOpen Access
    Studies on morphological, cultural characteristics and management of cercospora leaf spot of mungbean (Vigna radiata (L.) Wilczek)
    (Govind Ballabh Pant University of Agriculture and Technology;Pantnagar, 2005) Saxena, Purva; Tripathi, H.S.