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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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ThesisItem Open Access Management of cercospora leaf spot of vegetable cowpea (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt.)(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Chinnu Ravi; KAU; Radhakrishnan, N VThe study entitled “Management of Cercospora leaf spot of vegetable cowpea Vigna unguiculata subsp. ungiculata (L.) Verdcourt) was undertaken at the Department of Plant Pathology, College of Agriculture Vellayani and Coconut Research Station, Balaramapuram during 2015-2017 with the objective to study the symptomatology and etiology of Cercospora leaf spot of cowpea and to develop a management strategy. Symptomatology and etiology of Cercospora leaf spot disease was studied during the flowering or pod bearing stage of the crop from different locations near to College of Agriculture, Vellayani. Symptoms were observed on the leaves, pods and stem .Conidial dimension of the pathogen ranges from 24.64 to 57.6 µm x 1.06 to 2.7 µm and the conidial septation was around 10 to 18. Based on the conidial and mycelial characters, the pathogen was tentatively identified as Cercospora sp. The identity of the pathogen was further confirmed based on the morphological characteristics and the herbarium specimen send to National Fungal Culture Collection of India, (N.F.C.C.I), Pune as Pseudocercospora sp. aff. Pseudocercospora vignigena (F: Mycosphaerellaceae) In vitro pathogen suppression by spore germination assay revealed that the fungicide difenoconazole (0.1%) recorded 42.96 per cent reduction over control and was followed by propiconazole (0.1%) and hexaconazole (0.1%) which recorded 36.85 and 31.10 per cent reduction over control, respectively. The organic formulations, mineral oil (0.1%) and neem oil (0.5%) recorded only 21.88 per cent reduction over control and were statistically on par .KAU talc based formulation of Pseudomonas fluorescens at 2.0 % recorded 11.88 per cent reduction of spore germination over control. The pot culture studies conducted using eight best treatments (difenoconazole (0.1%), propiconazole (0.1%), hexaconazole (0.1%), carbendazim (0.05%), azoxystrobin (0.05%), mineral oil (0.1%) neem oil (0.5%) and P. fluorescens 2.0 %) selected from in vitro studies revealed that the foliar spray of 0.1 per cent difenoconazole recorded the minimum disease incidence (23.80%) and disease severity (8.23 %) that accounts to 54.80 and 76.06 per cent disease reduction over control respectively. In the case of organic formulations, mineral oil (0.1%) recorded the minimum disease incidence (30.04%) and disease severity (16.54%). The plant sprayed with KAU talc based formulation of P. fluorescens (2.0%) recorded 33.69 % disease severity reduction over control. With regard to pod yield, the plants treated with difenoconazole (0.1%) registered the maximum (0.523 kg/pot) yield with 88.80% yield increase over control while ,the untreated control plants registered the lowest yield (0.277kg/pot). Based on the results of pot experiment, a field study was conducted at Coconut Research Station, Balaramapuram to evaluate the efficacy of five best treatments (difenoconazole (0.1%), propiconazole (0.1%), mineral oil (0.1%) neem oil (0.5%) and P. fluorescens 2.0 %) selected from the pot culture studies. Among the fungicides, difenoconazole (0.1%) recorded the minimum (31.88%) disease incidence and disease severity (13.97%) compared to all other treatments. In the case of organic formulations, mineral oil (0.1%) gave the maximum (14.32%) disease suppression and the lowest disease incidence of 40. 57 %. With regard to yield, maximum pod yield was from the plot sprayed with difenoconazole (1620 kg /ha) followed by propiconazole (1386.5 kg /ha) treated plants. Even though, the application of P. fluorescens gave only 29.23 per cent of the disease suppression, it enhanced the yield by 52.27 per cent yield over the control. It was concluded that foliar application of difenoconazole ( 0.1% ) at an interval of 35, 50 and 65 DAS was found to be the most effective treatment in managing Cercospora leaf spot in vegetable cowpea besides supporting proportionately attractive pod yield (1620 kg/ha) at an acceptable B:C ratio (2.44:1).Among the organic formulations, mineral oil (0.1%) was found to be the effective treatment in controlling leaf spot with a pod yield of 1293 kg/ha . While, P. fluorescens recorded a pod yield of 1318 kg/ha with B: C ratio of 2.02:1ThesisItem Open Access Exploration of natural products from botanicals and fungal root endophytes for the management of cowpea mosaic virus(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Theresa Alex; KAU; Umamaheswaran, KThe present study entitled “Exploration of natural products from botanicals and fungal root endophytes for the management of Cowpea mosaic virus” was carried out at Department of Plant Pathology, College of Agriculture, Vellayani during 2014-2016, with the objective to develop serological and molecular tools for the early detection of Cowpea mosaic virus; and its management using natural products from botanicals and fungal root endophytes. Cowpea mosaic virus was maintained in local lesion host Chenopodium amaranticolor and cowpea (Vigna unguiculata var. sesquipedalis (L.) Verdcourt) variety Sharika by mechanical inoculation. On the newly emerged trifoliate leaves of cowpea, typical symptoms like mosaic and vein banding followed by leaf distortion were expressed seven days after inoculation (DAI). In C. amaranticolor, symptoms were expressed five DAI and on the inoculated leaves, localized yellow chlorotic lesions were observed. Fungal root endophytes Piriformospora indica and Fusarium pallidoroseum were maintained by continuous subculturing in Potato dextrose agar medium. The P. indica produced nine centimetre radial growth on nine DAI whereas F. pallidoroseum produced nine centimetre radial growth on five DAI in petri dishes. Serological studies carried out using Direct antigen coating – Enzyme linked immunosorbent assay (DAC-ELISA) and Dot immunobinding assay (DIBA) and molecular detection viz., Reverse transcription-polymerase chain reaction (RT- PCR), identified the mosaic causing virus in cowpea as Blackeye cowpea mosaic virus (BlCMV). Botanicals for the management of BlCMV were first screened on C. amaranticolor to find out their efficiency. Among the seven botanicals, Phyllanthus niruri recorded more than 80 per cent inhibition of local lesions in C. amaranticolor even at one per cent concentration. Highest inhibition (94.84 per cent) was observed for pre inoculation application of P. niruri at five per cent concentration. Standardization of co-cultivation method for the fungal root endophytes with C. amaranticolor and cowpea were conducted in jam bottles but no colonization of any fungal endophytes were observed in both C. amaranticolor and cowpea. Colonization studies in vermiculite-perlite (3:1) medium at the rate of 1% (w/v) conducted in protrays showed no colonization during the co-cultivation studies of F. pallidoroseum with both cowpea and C. amaranticolor. In case of P. indica, no colonization was observed for C. amaranticolor whereas 40.70 per cent root colonization was recorded in cowpea. In a study conducted to determine the effect of age of seedlings on colonization pattern observed using compound microscope, the highest efficiency (42.30 per cent) was recorded for five day old seedlings at twenty days after co-cultivation. Root biomass, number of secondary roots, tertiary roots, number of leaves and leaf area also showed high values for five day old seedlings at twenty days after co-cultivation whereas shoot biomass and root hairs per unit area showed highest values for seven day old seedlings at twenty days after co-cultivation. The best antiviral principle (AVP) and fungal endophyte viz., Phyllanthus niruri and Piriformospora indica respectively were evaluated in cowpea against BlCMV. Vulnerability of cowpea plants to BlCMV was found to reduce with P. niruri and P. indica treatments compared to that of control plants. The biochemical analysis to study the mechanisms involved revealed that cowpea plants pre inoculated with P. niruri was found to be superior followed by pre inoculation treatment with P. indica except for total sugar where maximum values for healthy was followed by pre inoculation treatment with P. niruri. Many defense and pathogenesis related (PR) proteins were induced in response to various treatments. The induction of novel proteins were more in cowpea leaves which were treated with P. niruri and P. indica than in control plants. Thus it is proved by serological and molecular detection methods that the virus causing mosaic disease in cowpea is BlCMV. For the management of this virus pre inoculation treatment of P. niruri (extract of one gram sample in 100 ml water) and pre inoculation treatment of P. indica (one gram mycelia in 100 ml vermiculite-perlite media) has been proved to be effective. It can be further validated under field condition.ThesisItem Open Access Cataloguing, Documentation and Management of fungal diseases of strawberry (Fragaria x ananassa Duch.)(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Amrutha, P; KAU; Reshmy VijayaraghavanStrawberry (Fragaria x ananassa Duch.), hybrid species of genus Fragaria, cherished for its characteristic flavour, colour and tentalizing aroma, is becoming an important table fruit of millions of people around the world. However, the crop is inflicted by several fungal diseases that reduce its commercial value. Hence, the present investigation was carried out to identify and catalogue the major fungal diseases of strawberry growing in Kerala. Purposive sampling surveys were carried out in strawberry growing tracts of Kerala viz., Wayanad, Idukki and Malappuram to collect infected samples and also to assess the incidence of fungal diseases during different periods viz., December-January, March-April and July-August. During the survey, four leaf spots (LSW-1, LSI-1, LSM-1 and LSI-2), four leaf blights (LBW-1, LBI-1, LBI-2 and LBM-1), one fruit rot (FRW-1) and two crown and root rots (CRI-1 and CRM-1) were noticed. Among the crown and root rot diseases, CRM-1 recorded the highest per cent disease incidence (PDI) of 82 per cent. Leaf blight (LBW-1) recorded maximum severity of 25.2 per cent among foliage diseases. Correlation studies were carried out to elucidate the influence of weather parameters on disease development. Symptomatology of different diseases was studied both under natural and field conditions. Pathogenicity was proved by mycelial bit inoculation and spore suspension method. Cultural and morphological characterisation of the isolates were carried out and for further confirmation of the identity upto species level, the isolates were sent to National Centre for Fungal Taxonomy (NCFT), New Delhi. The pathogens causing LSW-1, LSI-1 and LSM-1 were identified as Colletotrichum gloeosporioides, LSI-2 as Alternaria alternata, LBW-1 as Rhizoctonia solani, LBI-1 as Phoma exigua, LBI-2 as Curvularia lunata, LBM-1 as Pestalotiopsis longisetula and FRW-1 as Rhizoctonia solani. The two crown and root rot pathogens, CRI-1 and CRM-1 were confirmed as Fusarium oxysporum and Lasiodiplodia theobromae respectively. In order to recommend an appropriate management strategy for the aforesaid diseases, in vitro and in vivo evaluation were carried out using fungicides, biocontrol agents and organic formulations. Fungicides viz., carbendazim 12% + mancozeb 63%, propineb 70 WP, Bordeaux mixture, cymoxanil 8% + mancozeb 64%, difenoconazole 25EC and carbendazim 50WP were found effective against various foliage diseases. Carbendazim 12% + mancozeb 63%, cymoxanil 8% + mancozeb 64%, copper hydroxide 77WP and carbendazim 50 WP recorded cent per cent reduction in mycelial growth of Fusarium oxysporum (CRI-1). Similarly, carbendazim 12% + mancozeb 63%, copper hydroxide 77WP, cymoxanil 8% + mancozeb 64% recorded 93-100 per cent reduction of Lasiodiplodia theobromae (CRM-1). Results of dual culture studies with Trichoderma asperellum and Pseudomonas fluorescens against pathogens revealed 66.67 to 100 and 0 to 70.55 per cent control respectively. Likewise, organic formulations like Calphomil recorded an inhibition ranging from 13.3 to 75.33 per cent, whereas neem oil, panchagavya and baking powder + vegetable oil mixture could restrict the growth of pathogen only upto 34 per cent. In vivo experiment was conducted to study the efficacy of fungicides and biocontrol agents under natural conditions also. Accordingly, four major selected pathogens viz., C. gloeosporioides, P. longisetula, F. oxysporum and L. theobromae were subjected to molecular characterisation prior to in vivo studies. The sequence homology on molecular studies revealed that the isolates showed similarity to C. gloeosporioides, Neopestalotiopsis clavispora, F. oxysporum and L. theobromae. Results of the pot culture experiment revealed that Trichoderma asperellum showed better control against C. gloeosporioides compared to other treatments followed by carbendazim 12% + mancozeb 63%. Propineb 70 WP, T. asperellum and carbendazim 12% + mancozeb 63% reduced the severity caused by Neopestalotiopsis leaf blight disease. The combination fungicide carbendazim 12% + mancozeb 63% (0.2%) was found equally efficient against F. oxysporum and L. theobromae. Thus, the study has enlightened our knowledge on the various fungal diseases inflicting strawberry as well as the role of weather in disease development and the management practices using plant protection chemicals and bioagents both under in vitro and in vivo conditions. Hence, further studies should be focused to carry out multilocational trials in strawberry growing tracts of Kerala.ThesisItem Open Access Characterization and management of fungal pathogens of cabbage (Brassica oleracea var. capitata L.) and cauliflower (Brassica oleracea var. botrytis L)(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2017) Nusrath Beegum, C H; KAU; Yamini Varma, C KCabbage (Brassica oleracea var. capitata L.) and cauliflower (Brassicaa oleracea var. botrytis L.) are the most popular and widely cultivated cruciferous vegetables in Kerala. One of the main constraints in the production of these crops is the occurrence of fungal diseases, on which no detailed systematic studies have been conducted in Kerala. The study was carried out during 2015-2017 at College of Agriculture, Padannakkad with the objective to identify and characterize the fungal diseases of cabbage and cauliflower occurring in the selected districts of Kerala and to study the management of most severe and predominant diseases under in vitro and in vivo conditions. Purposive sampling surveys were conducted for the occurrence of fungal diseases in cabbage and cauliflower in Thrissur, Wayanad, Idukki and Kasargod districts and diseased plant samples were collected. Results of survey showed prevalence of eight different fungal diseases with a range of 5.4-69.3 per cent disease incidence and 8.1-68.3 percent disease severity in case of cabbage. In cauliflower, PDI and PDS were with a range of 3.1-52.2 percent and 4.9-44.2 percent respectively. Isolations done from the infected specimens collected during the survey yielded eight genera of fungal pathogens. For selecting the most potent isolate, virulence test was conducted, and used for further studies. Characterisation of the selected pathogens were carried out based on the cultural and morphological characters and identified up to generic level. Further identification of species of each genus was done by molecular characterization by sequencing the ITS region of each fungus by in silico analysis and confirmed as Alternaria brassicicola, Rhizoctonia solani, Collectotrichum gloeosporioides, Curvularia lunata, Choanephora cucubitarum, Pythium aphanidermatum and Fusarium equiseti. Symptomatology of these fungal diseases were studied in detail both under natural and artificial conditions. In vitro evaluation of fungicides and biocontrol agents was done against the selected sever pathogens. Ten fungicides at three concentrations and three bio control agents were selected for the studies. In vitro studies showed that against A. brassicicola the most effective fungicides at the recommended concentration were, trifloxystrobin 25% + tebuconazole 50%, tebuconazole 5EC and Bordeaux mixture with 100 percent inhibition. Against R. solani and C.lunata six fungicides viz., tebuconzole 5EC, copper oxy chloride 50 WP, trifloxystrobin 25%+tebuconazole 50%, propineb 70 WP and Bordeaux mixture produced 100 percent inhibion. Trifloxystobin 25%+tebuconazole 50%, tebuconazole 5EC and Bordeaux mixture were the three effective fungicides against C.gloeoporioides, F.equiseti and C. cucurbitarum which recorded 100 percent inhibition over control. But against P.aphanidermatum from cauliflower, copper fungicides showed a lead in the inhibition viz., copper oxycholride 50WP, copper hydroxide 77WP, Bordeaux mixture followed by mancozeb 75 WP. In vitro evaluation of biocontrol agents showed that T.viride was the most effective for controlling P.aphanidermatum with 75 percent inhibition followed by A.brassicicola with 67 percent inhibition. Antagonistic reaction of T.asperellum was mostly overgrowth on test pathogen. Similarly, P.fluorescens also showed maximum inhibition against P.aphanidermatum (50%). Effectiveness of the bacterial bioagent, B.subtilis showed maximum inhibition against R.solani. Three major pathogens viz., A. brassicicola, R.solani in cabbage and P.aphanidermatum in cauliflower were selected for the in vivo studies. Three biocontrol agents and funficides which showed inhibition above 60 percent were selected for in vivo evaluation. In vivo evaluation of fungicides for the management of Alternaria leaf blight of cabbage showed that trifloxystrobin 25%+tebuconazole 50% (0.03%) and tebuconazole 5EC (0.1%) were the best two fungicides showed 50 percent disease reduction over control followed by Bordeaux Mixture(1%). Yield of cabbage was also highest for these three treatments. Among biocontrol agents, T. viride was most effective in controlling the disease with a higher yield. For the management of Rhizoctonia leaf blight of cabbage, same two fungicides viz., trifloxystrobin 25%+tebuconazole 50% (0.03%) and tebuconazole 5EC(0.1%) were found to be most effective. B.subtilis was more effective than other two biocontrol agents which was significantly higher than control treatment. In vivo studies for the management of Pythium curd rot of cauliflower showed that trifloxystrobin 25%+tebuconazole 50% could produce 79 percent of disease reduction over control with higher yield. Among the bioagents, T.viride produced higher yield with 62 percent disease reduction. The present work resulted a detailed systematic study on the fungal pathogens of cabbage and cauliflower in selected districts of Kerala and emphasizes that trifloxystrobin 25%+tebuconazole 50% (0.03%) is the best chemical and T.viride is the effective biocontrol agent for field application for the management of these fungal diseases. Future line work should be concentrated on the residue analysis of these fungicides and formulation of a bio-intensive management strategy.ThesisItem Open Access Management of collar rot of cowpea caused by rhizoctonia solani kuhn using biofumigants(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Aparna, K P; KAU; Girija, V KThe study entitles “Management of collar rot of cowpea caused by Rhizoctonia solani kuhn using biofumigants” was undertaken in the Department of Plant Pathology, College of Agriculture, Vellayani during 2015-2017 with the objective to evaluate biofumigant nature of plants, plant oils and oil cakes against Rhizoctonia solani and to develop an ecofriendly management strategy for collar rot of cowpea using biofumigation. The pathogen causing collar rot disease of cowpea was isolated from the infected cowpea plants collected from the Instructional Farm, College of Agriculture, Vellayani. Pathogenicity was confirmed, virulence rating was done and the collar rot isolate R1 was found to be the most virulent one. Based on morphological and cultural characteristics, the pathogen was identified as the Rhizoctonia solani kuhn (Accession no. EF429212). This was further confirmed using molecular identification by ITS sequencing and showed 100 per cent similarity with Thanatephorus cucumeris, the perfect stage of R. solani. The antifungal and biofumigant action of ten different plants, four plant oils and four oil cakes/seed meals on mycelial growth of R.solani was evaluated under in vitro conditions in petridishes. Among these, incorporation of the leaf extracts of cabbage/ garlic creeper, lemongrass oil/ tea tree oil and mustard oil cake extract in PDA medium caused 100 per cent suppression of the pathogen. The invitro biofumigant activity of cabbage/cassava/garlic creeper/mustard, lemon grass oil/tea tree oil and the mustard oil cake was found to be statistically superior to all other treatements, and resulted in 100 per cent suppression of mycelial growth. The biofumigant action of ten different plants, four plant oils and four oil cakes with biocidal principles was tested by subjecting the sclerotia of R.solani to biofumigant action under confined conditions in sealed containers. Biofumigation with plants, plant oils and oil cakes, in general, exerted suppression of mycelial regeneration from sclerotia. The extent of suppression was found to increase with increase with increase in period of incubation with the biofumigants. Cabbage, cassava, garlic creeper and mustard were found to completely suppress the regeneration of mycelial growth from the treated sclerotia. Biofumigation with lemongrass oil/ tea tree/ mustard oil cake resulted in 100 percent suppression of regeneration of mycelium. Accordingly, plants such as cabbage, cassava, garlic creeper and mustard, plant oils such as lemongrass oil and tea tree oil, oil cakes such as mustard and groundnut oil cake were selected for further in vivo studies. An experiment was conducted under pot culture conditions to evaluate the efficacy of selected biofumigants involving 11 treatments and 5 replications in C.R.D. The treatments included the selected plants (50 g kg-1 soil), plant oils (5% soil drench) and oil cakes (10 g kg-1 soil) for suppression of collar rot of cowpea. The inoculated untreated control showed severe collar rot incidence (94.44%) compared to the treated pots. The maximum disease suppression (100%) was observed in cowpea plants grown on soil biofumigated with mustard plant/mustard oil cake which was on par with both chemical control check (0.1% carbendazim) and un-inoculated control. But the highest pod yield was recorded form plants grown on soil biofumigated with mustard oil cake (209.0 g) followed by treatment with mustard plant (185.4 g), which were significantly superior to the chemical control check (155.0 g) and un-inoculated control (143.0 g). These results revealed the enhanced effects of biofumigation for both disease suppression and growth enhancement. The population of soil microflora exhibited a decrease in the biofumigated treatements and an increasing trend after raising the crop. Among the predominant saprophytic fungi obtained from biofumigated soil, the isolated F1 exhibited 47.44% and among the two bacterial isolates, the isolate B2 caused 44.44% inhibition of the pathogen. The experiments revealed the scope of biofumigation for the management of R. solani under in vitro as well as in vivo. The collar rot caused by soil-brone pathogen, R. solani could be successfully managed by incorportation of either mustard plant (50g kg-1 soil) or tea tree oil (5% soil drench) or mustard/groundnut oilcake (10 g kg-1 soil)two weeks before raising cowpea.ThesisItem Open Access Evaluation and improvement of production technology of paddy straw mushroom (volvariella sp.)(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Brinda, G B; KAU; Susha S TharaThe study entitled “Evaluation and improvement of production technology of paddy straw mushroom (Volvariella sp.)” was performed in College of Agriculture, Vellayani during 2015-2017, with the objectives to explore the native isolates of Volvariella sp. and to study their morphological characters, improvement of techniques for production of paddy straw mushroom and to make an evaluation of the nutritional and organoleptic qualities. As a part of the study collections were made from various locations of Thiruvananthapuram and Kollam districts and thirteen different isolates of paddy straw mushroom were obtained. Morphological studies of different isolates of paddy straw mushroom showed that the sporocarps have black colour during the egg stage which become ashy to purplish white on maturity. Pileus is sub-umbonate with regular margin having free, smooth, pale salmon to moderate brown gills and central, cylindrical stipe with bulbous base encased in a thick volva. Microscopic studies revealed septate hyphae without any clamp connection, bottle shaped cheilocystidia, club-shaped basidia with four ovoid pink/moderate brown basidiospores. Cultures were isolated from the freshly collected mushrooms at egg stage through tissue culture technique and purified the cultures by hyphal tip method. Evaluation of cultural characters showed that the local isolate collected from Poonkulam had faster mycelial growth and it was taken as best isolate for further study. The morphological characters like size, weight of sporocarp of the selected isolate were also found promising. Study on different substrates for spawn production recorded that wheat grain, sorghum grain and paddy grain supported thick and fluffy mycelial growth. Considering the keeping quality, easy availability and nature of mycelial growth paddy grains was selected as the suitable substrate for spawn production in Kerala conditions. Comparison on the effect of different substrates for paddy straw mushroom production showed that paddy straw along with oil palm bunch waste on equal proportion amended with 5% gram flour was the best substrate for cultivation with a biological efficiency of 16.33%. Studies on the developmental morphology revealed that the fruiting body of paddy straw mushroom took 4-5 days for maturation from the pinhead emergence. Evaluation of different supplements for paddy straw mushroom production showed that 200ppm IAA supplementation during spawn run period yielded maximum (10.78% increase in biological efficiency over control). Assessment of different bed systems on production of Volvariella sp. recorded polybag method as more user friendly with maximum yield. Phorid flies were observed as the major pest during cultivation period. The competitor moulds identified were Trichoderma sp., Aspergillus sp., Penicillium sp. and Coprinus sp. Analysis for the proximate constituents in paddy straw mushroom exposed that it contains appreciable amount of protein (41.36 %) and fibre (16.98 %). Sensory evaluation was done using sauted mushroom recipe with Hedonic rating scale and observed that Volvariella sp. exceeded in colour, flavour, texture and taste attributes than Agaricus sp., Pleurotus sp. and Calocybe sp. Molecular characterization of the best isolate was carried out using ITS sequencing and the blast sequence was analysed in ClustalX2 software. Dendrogram was also constructed using TreeView software showing the phylogenetic relationship. Best isolate was identified as V. hypopithys and deposited in Directorate of Mushroom Research, Solan with the accession number DMRO – 943. The present study recommends that paddy straw mushroom can be successfully cultivated in Kerala using paddy straw and oil palm bunch waste in equal proportion as substrate having 5% gram flour amendment, supplemented with 200 ppm IAA on mycelial development stage by polybag method or wooden box method. Paddy straw mushroom was found to be high in terms of protein content and organoleptic attributes.ThesisItem Open Access Organic strategy for the management of sheath blight disease of rice(Department of Plant Pathology, College of Agriculture, Vellayani, 2017) Karthika, S R; KAU; Sajeena, AThe study entitled “Organic strategy for the management of sheath blight disease of rice” was undertaken at the Department of Plant Pathology, College of Agriculture, Vellayani and IFSRS, Karamana during 2015-2017 with the objective to develop an eco-friendly disease management package for sheath blight disease of rice using organic preparations, botanicals, soil amendments and non-hazardous chemicals. Seven isolates of Rhizoctonia solani was isolated from sheath blight infected rice plants collected from seven different rice growing tracts of Thiruvananthapuram district during Kharif, 2016. The symptoms of the disease were observed during the active tillering stage of the crop. Pathogenicity was confirmed by proving Koch’s postulates. The isolate collected from Karode (I6) took seven days and the other six isolates took three days for symptom development. Virulence rating by artificial inoculation on potted plants proved that the isolate collected from Attingal (I2) produced the maximum number of infected tillers (4.66) as well as the maximum relative lesion height at 5th (9.20%), 7th (15.70%), 10th (19.03%) and 15th (20.96%) days after inoculation. Thus, I2 was found to be the most virulent isolate. Based on the morphological and cultural characteristics, the pathogen was identified to be Rhizoctonia solani Kuhn (Accession no: KX674527). Further, molecular identification by ITS (Internal Transcribed Space) sequencing revealed 100 per cent similarity with R. solani AG-1 IA isolate CSU8. In vitro pathogen suppression studies revealed that fermented egg-lemon juice extract (10%), panchagavya (5%), garlic extract (10%), potassium silicate (1%), lime (12.5%) and fermented weed (Setaria barbata) extract (100%) resulted in 100 per cent inhibition of the mycelial growth of R. solani. Dipping sclerotia for 24 hours in fermented egg-lemon juice extract (10%), panchagavya (5%), lime (12.5%) and fermented weed (Setaria barbata) extract (100%) resulted in complete (100%) suppression of mycelial regeneration from sclerotia. Analysis of the major nutrients (N, P, K) and pH of the various treatments revealed that fermented weed extract, fermented egg-lemon juice extract and panchagavya were highly acidic (pH of 4.9, 4.5 and 4.2 respectively). The total N content was high in panchagavya (0.02 %) followed by fermented egg-lemon juice extract (0.01%) whereas the total K content was high in panchagavya (0.03%) followed by potassium silicate (0.01%). The P content was comparatively high in panchagavya (0.007%) followed by fermented egg-lemon juice extract (0.006%). The pot culture experiment for the management of sheath blight in rice (var. Uma) revealed that the maximum suppression of the vertical spread of the disease was observed in fermented egg-lemon juice extract (79.43%) and garlic extract (79.36%) sprayed plants which were found to be on par with the fungicide check, hexaconazole (79.36%). The percentage horizontal spread was the least for fermented egg-lemon juice extract (11.12%) and potassium silicate (16.93%) sprayed plants which were also on par with the fungicide check (10.44%). However, the highest grain yield was recorded in the plants sprayed with fermented weed (Setaria barbata) extract (15.98g) followed by fermented egg- lemon juice extract (15.33g) and garlic extract (14.66g) sprayed plants. Analysis of the major nutrients in the plants at the time of harvest revealed that the total N content was the maximum for the plants sprayed with garlic extract (1.645%) whereas the total K content was the maximum for the plants sprayed with potassium silicate (3.601%). Thus, the present study revealed that three treatments viz., fermented egg- lemon juice extract (10%), potassium silicate (1%) and garlic extract (10%) resulted in improved biometric and yield attributes of rice plants as well as in the reduction of sheath blight disease incidence. However, four foliar sprays at 45th, 60th, 75th and 90th DAS of potassium silicate at one per cent concentration was found to be the most economical and effective treatment in improving the yield as well as in reducing the sheath blight disease incidence and was found to be on par with the fungicide check.