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Kerala Agricultural University, Thrissur

The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively. Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively. On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs. In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc. During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU). Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.

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20153
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Subject: Plant Pathology × End date: 2015 × Start date: 2015 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Efficacy of ligno-phenolic compost in the suppression of soil borne plant pathogens
    (Department of plant pathology, College of horticulture, Vellanikkara, 2015) Gleena Mary, C F; KAU; Sally K, Mathew
    The study on the “Efficacy of ligno-phenolic compost in the suppression of soil borne plant pathogens” was carried out at College of Horticulture, Vellanikkara during 2011 -2014. The major objectives were to develop a microbial consortium for rapid composting of lignintannin rich agrowastes and also to study the effect of these composts on the management of leaf blight of amaranth and bacterial wilt of tomato. Sample of soils and partially degraded substrates were collected from 15 sources of 34 locations. Among them, ayurvedic wastes yielded maximum population of cellulose and lignin degraders whereas, tannin degraders were more in the samples of teak plantation. A total of 378 microbial degraders were isolated which included 125 cellulose, 133 lignin and 120 tannin degraders. Actinomycetes were the predominant degraders of cellulose and fungi were dominant among both lignin and tannin with majority belonged to Aspergillus spp. and Penicilium spp. In vitro evaluation of degraders on respective selective media showed diffusion zones more than 4cm by 31 cellulose, 39 lignin and 33 tannin degraders. Fungi were the most efficient degraders of cellulose, lignin and tannin. Thirty five degraders found effective on their respective selective media showed ability to degrade all the three chemical components. In vitro decomposition of 33 degraders on respective host substrates recorded lowest maturity periods of 40 and 43 days for the degraders isolated from ayurvedic waste and coir pith. The degraders, ALF-26, CLF-13, CCB-8, ECF-2, ECA-8, TLF-8, CaLF-5 and ATY-1were most effective on their respective host substrates and also on other tested lignintannin rich substrates in vivo. All the 22 selected degraders were found mutually compatible. Based on the ability to degrade all the three chemical components, early maturity of composting, type and species of organisms and mutual compatibility, 10 degraders viz. Trichoderma harzianum, Paecilomyces variotii, Penicillium oxalicum, P. chrysogenum, Talaromyces sp., Streptomyces albus, S. niveus, Arthrobacter sp. and Massilia sp.were selected for the formulation of microbial consortium. Screening of selected consortium under in vitro and in vivo condition showed early maturity of 35 and 43 days in mixed substrate followed by coir pith with 35 and 45 days. In large scale composting of various agrowastes with microbial consortium, cow dung slurry and the combination of both, the minimum maturity period was observed with microbial consortium as compared to other treatments recording 30, 35, 40 and 55 days for mixed substrate, coir pith, ayurvedic waste and leaf litters respectively. Composting with microbial consortium resulted in drastic reduction of C:N ratio of the composts with 47 -81 per cent reduction from the initial and the lowest in ayurvedic compost (10.4:1) .Composts treated with microbial consortium recorded neutral to alkaline pH and high contents of N, P and K with maximum N and P in ayurvedic and K in coir pith compost. Traces of lead detected in all compost samples were below the permissible limits. Composting with consortium showed reduction in cellulose, lignin and tannin contents with maximum reduction in ayurvedic (49.38 %), coir pith (49.02%) and leaf litter composts (98.95%) respectively. The degraders of the consortium were thermophilic and recorded extra cellular enzyme activities of cellulase, lignin peroxidase, polyphenol oxidase, amylase, catalase, protease and xylanase. The selected degraders showed antagonism against six major soil borne pathogens viz. Pythium sp., Phytophthora sp., Rhizoctonia sp., Fusarium sp., Sclerotium sp. and Ralstonia solanacearum and T. harzianum was the most effective one. In the field evaluation of various composts in the management of bacterial wilt of tomato and leaf blight of amaranth, application of ayurvedic compost was effective in reducing both diseases. In addition, coir pith and leaf litter composts also reduced bacterial wilt incidence and mixture compost in case of leaf blight.
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    ThesisItemOpen Access
    Enhancement of resistance to bacterial wilt in tomato by endophytic microbial communities
    (Department of Plant Pathology, College of Horticulture, Vellanikkara, 2015) Deepa James; KAU; Sally K, Mathew
    The study on “Enhancement of resistance to bacterial wilt in tomato by endophytic microbial communities” was conducted in the Department of Plant Pathology, Department of Agricultural Microbiology, and Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during the period 2011-2014. The endophytes were isolated from root and stem of healthy tomato plants from 16 locations of north, central and south Kerala. Endophytic microbial population varied with the plant samples and the population was more in root than stem. Bacterial population was higher than fungi and actinomycetes in root and stem. Among 154 endophytes isolated, 12 out of 79 bacteria, 16 out of 68 fungi, and four out of seven actinomycetes were antagonistic to R. solanacearum in in vitro. Among them, five bacteria, eight fungi, and two actinomycetes were promising in planta. Mutually compatible endophytic isolates were selected for the development of consortia and these were identified based on cultural, morphological and molecular characters. Of the five consortia tested, the one consisted of Trichoderma viride-1, T. viride-2, T. harzianum-1, Bacillus subtilis, and Streptomyces thermodiastaticus showed effect in reducing wilt incidence. Comparative study of the microbial consortium with individual endophytes showed the higher efficacy of consortium in reducing the wilt incidence. The endophytes were reisolated from soil, root, and stem of tomato plants. In pot culture experiment, the consortium applied as seed treatment + seedling dip + soil application at 45 DAP showed the minimum wilt incidence. Studies on the mechanism of antagonism of endophytic isolates showed, positive reaction towards ammonia and negative for HCN and siderophore production. The volatile and nonvolatile metabolites of the endophytes inhibited the pathogen. The endophytes showed varying levels of IAA and salicylic acid production with the maximum in T. harzianum-1 and B. subtilis respectively. Study on the effect of secondary metabolites of endophytes on the disease indicated that, seedlings dipped first in culture filtrate for 2 h and later dipped in bacterial inoculum for 30 min before planting showed the lowest per cent wilt incidence with the minimum for T. viride-2. Induction of systemic resistance was studied by assay of defense related compounds such as phenols, oxidative enzymes and PR proteins. The plants treated with microbial consortium showed higher activity of the defense related compounds with the maximum in plants inoculated with both consortium and pathogen. Field evaluation of endophytic consortium against bacterial wilt showed reduction in wilt incidence of 40.85 per cent in highly susceptible variety, PKM-1, 46.94 per cent in susceptible F1 hybrid, COTH-3, and 52.81 per cent in moderately resistant variety, Mukthi. Thus, the study revealed that, the application of endophytic consortium can enhance the resistance mechanism in tomato against bacterial wilt pathogen, R. solanacearum.
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    ThesisItemOpen Access
    Phenotypic and molecular characterisation of phytophthora sp. inciting leaf fall of nutmeg
    (College of Horticulture, Vellanikkara, 2015) Sumbula, V; KAU; Sally, K Mathew
    The study on ‘Phenotypic and molecular characterisation of Phytophthora sp. inciting leaf fall of nutmeg’ was conducted in the Department of Plant Pathology, College of Horticulture,Vellanikkara during 2014-2015. The major objectives were to study the cultural, morphological and molecular characters and variability of different isolates of Phytophthora sp. associated with leaf fall of nutmeg and also to study the host range of the pathogen and to chalkout suitable management strategies Isolation of the pathogen from 18 samples from different locations revealed the association of the fungus, Phytophthora sp. and its pathogenicity was established under lab and in vivo conditions. Inoculation of the pathogen with culture disc on injured lower leaf surface showed early infection than that with zoospore suspension. Symptoms observed on leaves, shoot and fruits were almost same under both natural and artificial conditions. Variation in virulence was noticed among the isolates collected from different locations. The isolates, PPaL-1 and PPaF-17, from Parakkadavu, Thrissur and PSrL-10 from Sreemoolanagaram, Ernakulam were highly virulent. PKoL-2, the isolate from Kodissery was less virulent and other 14 were moderately virulent. Cultural and morphological characters of the isolates of pathogen were studied with different media viz. carrot agar, potato dextrose agar, oat meal agar, coconut water agar and V8 juice agar. Variation in cultural characters among the isolates was observed only in carrot agar and the variation in growth rate was noticed among the different media. Morphologically, mycelia of Phytophthora isolates from nutmeg were branched, coenocytic and hyaline and the sporangia were borne terminally /laterally on the sporangiophore in sympodial fashion, caducous, semi papillate, ovoid/elongated-ovoid/ellipsoid in shape with average size of 31.9-49.5 x 22.3 – 27.9 μm, L/B ratio of 1.4 – 1.8 and pedicel length of 10.21 – 20.24 μm. Early sporangial production was noticed in carrot agar and potato dextrose agar and the maximum count was in oat meal agar and carrot agar. Numerous chlamydospores were observed in all media. Comparison on the cultural and morphological characters of Phytophthora isolates of nutmeg with other Phytophthora spp. such as P. meadii, P. palmivora, P. capsici, P. colocasiae, P. citrophthora and P. ramorum revealed that, Phytophthora isolates from nutmeg could not be completely fitted into the phenotypic description of any of these known Phytophthora species. However, they showed some similarity to P. meadii, P. colocasiae and P. ramorum. In molecular characterisation, out of 18 isolates of nutmeg Phytophthora, 15 showed maximum homology with P. colocasiae and three viz. PPoL-3, PMaL-4 and PVaL-15 with P. meadii. Isolates PPaL-1, PKoL-2, PVeL-5, PKtL-6, PKaL-7, PMtL-8, PThL-9, PTuL-11, PKnL -12, PPaF-17 and PMoF-18 also showed homology with P. citrophthora and PMaL-4 and PSrL-10 with P. botryosa. Host range of Phytophthora isolate of nutmeg includes, rubber, vanilla, rose, Coreopsis, Eucalyptus and Citrus. Nutmeg is also a host of P. meadii of vanilla and P. citrophthora of Citrus and non host of P. palmivora, P. capsici, P. colocasiae, P. meadii of arecanut, rubber and cardamom. Rose is also found to be a host of P. meadii isolates of arecanut, rubber, cardamom, vanilla and P.citrophthora of Citrus. The cultural, morphological and molecular characters, host range and cross infectivity studies of various Phytophthora isolates could not revealed the exact identity of these isolates, as the distinguishing features overlapped among the various Phytophthora species. In vitro evaluation of chemicals / bioagents showed complete inhibition of the pathogen with 1% Bordeaux mixture, copper hydroxide (2g/l), copper oxychloride (2.5g/l), potassium phosphonate (3ml/l), combination fungicides, iprovalicarb + propineb (1.5 and 2.0g/l), cymoxanil + mancozeb (2g/l) and Trichoderma viride -1, T. harzianum and T. viride -2, the isolates from nutmeg and the reference cultures viz. T. viride (KAU) and T. harzianum (IISR). In in vivo experiment, all treatments were superior to control of which, spraying of 1% Bordeaux mixture + soil drenching of copper hydroxide (2g/l) and spraying of 1% Bordeaux mixture and soil application of T. viride showed maximum reduction of the disease. In addition, spraying and drenching of copper hydroxide and copper oxychloride were also found equally effective.