PhD Thesis
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Item Silicon availability of tropical soils with respect to rice nutrition(Department of Soil Science and Agricultrural Chemistry, College of Horticulture,Vellanikkara, 2016-03-28) Arya Lekshmi V; Jayasree Sankar, SSilicon (Si) is the second most abundant element in soil. The amount of silicon in soil depends on parent material, soil type, pedogenic process and landscape. In soil solution, Si is present as monosilicic acid which is the only form that the plant can absorb from soil. The productivity of rice is comparatively low in soils of Kerala. As a ̳Si – accumulator‘, rice can benefit from Si nutrition. The application of Si can enhance growth and yield of rice. With this background, studies were conducted to categorize major rice growing soils of Kerala according to plant available silicon and to evaluate the efficacy of different sources of silicon including rice straw in wetland rice. The release of silicon from different soils added with various silicon sources under different water regimes was also monitored. Soil samples were collected from five different locations representing major rice growing regions of Kerala viz., Kuttanad, Kole land, Pokkali, sandy and lateritic to categorize them according to plant available silicon. The available Si ranged from 7.70 mg kg -1 (sandy soil) to 34.91 mg kg -1 (Kole land soil) in the order Kole land > Pokkali > lateritic > Kuttanad > sandy soil. All the soils under study were categorized as low in available Si. The available Si had positive correlation with organic carbon, available N, Ca, Mg, Fe, Mn, Zn, exchangeable K, Ca, Mg and CEC and negative correlation with available boron, AEC and silica-sesquioxide ratio. These soils were subjected to fractionation of silicon. The major fractions of Si were mobile, adsorbed, organic, occluded, amorphous and residual Si. The percentage distribution of fractions of Si in these soils were in the order; residual Si > amorphous Si > occluded Si > organic Si > mobile Si > adsorbed Si. Quantity – intensity relationship of five major rice growing soils at two temperatures viz. 25 0 C and 40 0 C were studied. The highest buffer power was indicated by Kuttanad soil followed by Pokkali and sandy soils at 25 0 C. It clearly indicated that these soils have a higher power to retain Si on solid phase and replenish its concentration in soil solution as and when it is depleted through plant uptake or leaching. The equilibrium Si concentration and the amount of Si adsorbed by each soil were used to test the fitness of data to the adsorption isotherms viz., Langmuir, Freundlich and Temkin. The data obtained from the adsorption experiments fitted into Freundlich and Temkin equations, but not to Langmuir equation at 25 0 C. At 40 0 C no adsorption equations were obtained for any soil.An incubation study was conducted to know the extent of release of Si on addition of different sources of silicon such as rice husk ash, biodecomposed rice husk, calcium silicate and sodium silicate in five rice growing soils under submerged water regime (SWR) and field capacity water regime (FCWR). Addition of Si significantly increased the release of available Si in all soils except Kole land soil after a month. Kole land soil showed higher release of available Si after two months. The highest release of available Si was at SWR in case of Kole land and Kuttanad soil, where as Pokkali, sandy and lateritic soils showed more release of available Si at FCWR. Irrespective of soils, treatment with sodium silicate showed higher release of available Si. Total Si showed a decreasing trend over the period of incubation for three months in all the soils. A field experiment was conducted at Agronomic Research Station, Chalakudy to evaluate the efficacy of different sources of silicon including rice straw in wetland rice. Rice husk ash, biodecomposed rice husk, calcium silicate and sodium silicate were used as source of Si along with fertilizers as per package of practice recommendation (NPK alone). The maximum number of panicles per hill, number of spikelets per panicle, thousand grain weights and minimum number of unfilled grains per panicle were recorded in treatment with calcium silicate application. The maximum grain yield of 6.90 t ha -1 was recorded in treatment T 5 (T 2 + Calcium silicate) and significantly superior (fig.54) over all other treatments. This increase in yield may be due to the effect of application of Si on soil fertility, nutrient uptake, and plant growth. The direct effect of Si fertilization on increased number panicle per hill, number of spikelets per panicle, and thousand grain weight and decreased number of unfilled grains per panicle might be the reason for increased grain and straw yield in treatment with calcium silicate. The treatment with POP + sodium silicate showed the highest uptake of Si by grain and straw of rice. The sources of Si had no residual effect on grain and straw yield of succeeding rice crop. In general, sandy soil low in available Si had a high response to applied Si in achieving higher grain yield.Item Nutrient and moisture optimization in banana (Musa AAA. Grand Nain)(Department of Agronomy, College of Agriculture, Vellayani, 2016) Bindhu, J S; Girija Devi, LItem Developing value added and diversified products from coconut(cocos nucifera L)(Department of Home Science, College of Agriculture, Vellayani, 2004) Neelofar Illiaskutty; Mary Ukkuru, PItem Genetic variability and plus tree selection in natural populations of Malaveppu (Melia dubia Cav.)(Department of Forest biology and tree improvement, Vellanikkara, 2019) Binu N Kamalolbhavan; Santhoshkumar, A VItem Characterization and identification of black pepper accessions (Piper nigrum L.) for stress tolerance and quality(Department of plant breeding, College of Horticulture, Vellanikkara, 2019) Prakash, K M; Jiji JosephItem Ground water resources modelling of a watershed using modflow(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Sajeena, S; Kurien, E KA study on ‘Ground water resources flow modelling and mapping of a watershed using MODFLOW’, was carried out for Kadalundi river basin of Malappuram District in Kerala. The objectives of the research were 1. to study the aquifer characteristics of the study area, 2. to study the spatial and temporal ground water variations in the study area, 3. to identify the potential ground water zones within the study area using earth resistivity studies and 4. to develop a ground water flow model for the river basin using Visual MODFLOW. Kadalundi river basin has a drainage area of 1122 km 2 with a main stream length of 130 km, originating from the Western Ghats at the western boundary of Silent Valley. River flows through the district of Malappuram and downstream reach of the river falls into Arabian Sea. In order to evaluate the aquifer characteristics of the study area, spatial and temporal variations of ground water level of dug wells and bores wells were analyzed separately. Monthly water table data from 16 bore wells and 14 dug wells during the period from 2008 to 2013 were used for the study. From the p re and post monsoon water table and piezometric water level variations and from the water table and piezometric water level hydrograph studies, it was observed that the water table and piezometric level fluctuation in low land, mid land and high land area were correlated with rainfall except at some locations like Kottakkal, Marakkara and Tanur. Hydraulic continuity studies were carried out with the help of statistical analysis and it indicated that the hydraulic continuity of ground water and surface water exists between aquifers of dug wells and bore wells in major part of study area. Areas like Thirurangadi, Kottakkal and Some part of Perinthalmanna, variation of piezometric water level was poorly correlated with rainfall, which indicated that hydraulic continuity does not exist in that areas and these areas are suitable for deep bore wells.Vertical Electrical Sounding (VES) method was carried out using Signal Stacking Resistivity Meter (MODEL-SSR-MP-ATS) at 22 locations. The apparent resistivity values obtained from the resistivity meter were interpreted with the help of ‘IPI2WIN’ software to obtain the layer parameters. The sounding curves are of A,H,K,Q,HK and KH types reulting in 3 to 4 layer sequence. The curves are prominently of H, Q, K and A type indicating the presence of three layer and combination of curves like HK and KH indicating the four sub surface layers. Most parts of the study area are dominated by H type curve which indicates the presence of good quantity groundwater. Visual MODFLOW software version 2.8.1 developed by Waterloo Hydrogeologic Inc. was used for the flow modelling of the study area. The conceptual model for the study area was developed based on the base map of Kadalundi river basin, topo sheet of the area, well logs at 30 sites and the data obtained from the geophysical studies conducted in the study area. Discretization was done by dividing it into 62 rows and 136 columns with a grid spacing of 500 m x 500 m throughout the area and the cells outside the boundary of the study area were made as inactive. Monthly pumping rate from 35 pumping wells and monthly water level data from thirty head observation wells of Ground Water Department (GWD), Government of Kerala were used as well inputs of Visual MODFLOW. Hydrogeological parameters such as hydraulic conductivity, specific storage, specific yield, porosity and initial heads and boundary conditions of the model domain including constant head, rivers, drains, recharge and evapotranspiration were used as input of Visual MODFLOW. After uploading input parameters, the model was run for steady state and transient state subsequently. Model was developed and calibrated using four years data from 2008 to 2011 and a reasonably good agreement was obtained between computed and observed water levels. After calibration, the model was validated for t w o years data of 2012 and 2013. The root mean square error (RMSE) for almost all the wells during validation were reasonably low and within acceptable limits except a few wellsvery close to the river which are most likely to be influenced by the interflow of river. After the model development and validation, it was used to predict the flow head for the next 15 years assuming five per cent yearly decrease in recharge and also to predict the ground water condition by increasing the pumping rate by 10, 25 and 50 per cent of pumping rate of the validation period (2013). From the modelling studies, it can be concluded that the Kadalundi river basin will remain safe for next five years from the point of future ground water development and subsequently the water table may reach the bed rock. This necessitates artificial ground water recharge techniques to supplement the recharge of rainfall to the ground water.Item Heterosis breeding in sesame (Sesamum indicum L.).(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Gayathri, G; Dijee BastianThe study entitled ‘Heterosis breeding in sesame (Sesamum indicum L.)’ was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara. The objectives of the study were to collect and evaluate different genotypes of sesame for morphological traits and yield attributes, to identify useful parents producing heterotic crosses and developing hybrids in sesame. The study also intended to develop male sterile lines in sesame through interspecific hybridization with Sesamum malabaricum. Sesamum indicum and Sesamum malabaricum accessions were collected from Kerala and Tamil Nadu and evaluated for their morphological traits. Wide range of variation was noticed for characters like plant height, number of days to flowering and seed yield per plant which contributed maximum to genetic divergence. The genotypes studied were grouped into six clusters. High genotypic coefficient of variation (GCV) was recorded for number of capsules per plant, plant height, seed yield per plant and number of branches per plant. High heritability with high genetic advance as per cent of mean was recorded for number of days to flowering, plant height, number of branches per plant, number of capsules per plant and seed yield per plant. This indicates that the characters are governed by additive gene effects and selection for these traits will be effective. Association analysis revealed that seed yield per plant was correlated to plant height, number of capsules per plant and number of days to flowering. Path coefficient analysis indicated maximum positive direct effect by number of capsules per plant, capsule length, plant height and 1000 seed weight on seed yield per plant. In order to develop hybrids, fourteen parents were selected based on the per se performance of the genotypes. They were crossed in line X tester mating design. Forty eight hybrid combinations obtained were raised in the field along with the parents and evaluated for their heterosis and combining ability effects. Parental genotypes AVTS-06-5, AVTS-06-10, IVTS-06-12, KYM-1, Tilak and TMV-6 were identified as high combiners based on general combining ability (gca) effects. Two combinations viz. AVTS-06-5 X KYM-1 and IVTS-06-12 X TMV-3 had significant values of per se performance, specific combining ability (sca) effects and standard heterosis for seed yield per plant. They can be evaluated for their hybrid vigour over locations and seasons. The crosses AVTS-06-5 X TMV-3, AVTS-06-5 X TMV-6 and TCR 3279A X KYM-1 have been identified as potential cross combinations for isolation of promising segregants as the parents involved in these crosses had high significant gca effects for seed yield per plant but the hybrids recorded non significant sca effects. Interspecific hybridization between S.malabaricum and S.indicum was attempted to develop male sterile lines. Seed set was noticed in three interspecific hybrids which failed to germinate due to embryo abortion. Hence these embryos were rescued and raised in vitro to obtain the hybrids.Item Documentation and quality evaluation of selected traditional foods of central zone of Kerela(Department of Home Science, College of Horticulture, Vellanikkara, 2009) Aneena, E R; Indira, VThe study entitled “Documentation and quality evaluation of traditional foods of central zone of Kerala” was taken up with the objectives of identifying and collecting information on the various traditional foods of central zone of Kerala and documenting their mode of processing, and evaluating quality characteristics of the selected less used traditional foods. The study was conducted in four districts namely Eranakualm, Thrissur, Palakkad and Malappuram comprising the central zone of Kerala. Senior citizens who possess the details of traditional food items and preparations in each locality were selected as the respondents. The respondents were categorised based on the communities they represent. Details of traditional food habits with respect to preference for traditional foods, the reasons for the preference, frequency of preparation of traditional foods, traditional foods prepared during special occasions, festivals/rituals and during physiological conditions and traditional foods included for breakfast, lunch, dinner, and snacks were collected from the selected respondents. Transition that occurred in the traditional food pattern and in the preparation of traditional foods was also collected. Quality evaluation of selected traditional foods was conducted at laboratory level with respect to chemical constituents, acceptability and microbial growth. The foods were packed in suitable packaging materials and stored under different conditions and the quality evaluation of foods was carried out during storage. Majority of the respondents preferred traditional foods due to their health benefits and palatability. Most of the respondents prepared traditional foods for break fast and lunch and also prepared different traditional snack items. Most of the respondents did not prepare traditional health foods at home due to the laborious procedure involved in the preparation and the commercial availability of these products. Respondents belonging to different communities prepared various traditional foods during special occasions, festivals/rituals and consumed traditional foods during different physiological conditions. Most of the respondents included traditional food items for breakfast and lunch. Changes were observed in the traditional food pattern and traditional foods over different years with respect to ingredients, method of preparation and vessels/ utensils used for preparation. The recent trend of food consumerism was portrayed by the increased frequency of eating out habits, purchase of instant mixes and bakery items. From the traditional food items collected, twelve traditional foods namely inderiyappam, kala kala, kaliyadakka, karinellikka, madhura puttu, manda, muttayappam, niracha pathiri, paniyaram, poruvelangai, rankayyan and vishu katta and three beverages namely, cherunaranga then vellam, inji paneeyam and paanakam which were least used, nutritionally viable and organoleptically acceptable were selected and replicated under laboratory level. Quality evaluation of these foods was conducted initially and during storage. Evaluation of the chemical composition of the traditional foods showed that most of the traditional foods are rich in certain macro and micro nutrients. Organoleptic evaluation of the replicated foods indicated that most of the traditional foods were acceptable to the younger generation. The replicated traditional foods were packed in suitable packaging materials and stored under ambient or ambient and refrigerated conditions for different intervals. Among the different replicated foods inderiyappam, muttayappam, niracha pathiri, rankayyan and vishu katta were highly perishable and could be stored only for a day. The quality attributes of paanakam, cherunaranga then vellam and inji paneeyam also decreased considerably during storage. From the present study, it was found that the selected traditional food items could be replicated under the prevailing conditions without change in their quality aspects. Hence, these technologies should be popularised as an attempt to conserve the traditional cuisines of Kerala.Item Enhancement of propagation efficiency in exotic varities of heliconia(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2008) Reshmi, C R; Sheela, V LItem Women empowerment through group action in the kudumbashree programme of kerala: a multidimensional analysis(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 2007) Priya Devi, R; Mothilal Nehru, S