PhD Thesis

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End date: 2019Subject: search.filters.subject.Rice

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    Studies on induced mutations in rice (Oryza sativa L.)
    (Division of genetics and plant breeding ,Agricultural college and research institute , Coimbatore., 1971) Gopinathan Nair, V
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    Studies on the rice swarming caterpillar , Spodoptera mauritia boisduval in Kerala
    (Division of entomology ,Agricultural college and research institute ,Vellayani., 1967) Thomas, B; M R G K Nair
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    Nutrient dynamics if the rice based cropping systems
    (Department of soil Science and Agricultural Chemistry, College of agriculture, Vellayani, 1989) Sundaresan Nair, C; Subromonia Aiyer, R
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    Factors governing response of rice to liming in Kerala soils
    (Department of soil science and Agricultural chemistry, College of Agriculture Vallayani , Trivandrum, 1986) Mary kutty, K C; Subramania Aiyer, R
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    Optimization of agronomic resources for maximizing grain and mill yield of rice
    (Department of Agricultural Engineering, Indian Institute of Technology, Kharagpur, 1976) Kannan, Mukundan; Pande, H K
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    Biochemical and molecular characterisation of njavara types of rice (Oryza sativa L.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2005) Sanal Kumar, P; Elsy, C R
    Characterisation and evaluation of Njavara types of rice (Oryza sativa L.) was under taken in the Department of Plant Breeding and Genetics and Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during 2001 - 2005 with the aim to characterise the Njavara genotypes based on morphological, biochemical and molecular characteristics, to evaluate its nutritional qualities and to analyse the stability of quantitative and nutritional traits. Morphological characterisation indicated that seven Njavara genotypes included in the present study exhibited similarity among themselves and with check variety for most of the qualitative characters. Some variations were observed with panicle type, panicle axis, apiculus colour, lemma and palea colour, seed coat colour and presence of awn. The Njavara genotypes viz., N1 and N2 (both Njavara types from Chittoor, Palakad) and N6 (Njavara type from Alwaye, Ernakulam) showed lemma and palea colour of black patches or furrows on straw background with black coloured apiculus, N3 and N4 (both Njavara types from Telllicherry, Kannur) showed lemma and palea colour of brown furrows on straw background with brown coloured apiculus, while N5 (Njavara type from Kottakkal, Malappuram) and N7 (Njavara type from Thrissur) showed a lemma and palea colour of gold furrows on straw background with an apiculus colour of straw. Njavara genotypes showed lesser days to maturity (67.9 to 79.1 days) with an average grain yield for Njavara genotypes ranging between 945.56 kg ha-1 and 2127.14 kg ha-1 was low compared to that of check varieties (2491.73 kg ha-1). Majority of the Njavara genotypes expressed high protein content than check varieties. The geotypes N2 and N6 were recommended to be included in weaning and invalid foods and diets during pregnancy and lactation. The genotypes N1, N2, N6 and N7 appeared to have better nutritive value based on the content of free amino acids. Most of the Njavara genotypes had intermediate amylose content ensuring consumer acceptance. Among the Njavara genotypes N3 has highest soluble carbohydrate content while others showed medium soluble carbohydrate content and are desirable as component of weaning and invalid food due to reduced gelatinization period and easy digestibility. Variability studies indicated that grain yield, straw yield and amylase activity provided a good genetic base for selection. The Njavara genotypes showed high heritability with high genetic gain for quantitative and nutritional characters. Correlation studies revealed that grain yield showed high positive correlation with high leaf width, days to 50 per cent heading, panicle length, days to maturity, straw yield, 1000 grain weight, grain width and amylose content. Nutritive factors like protein content and soluble carbohydrate content showed significant negative genotypic correlation with grain yield. Genotype x environment interaction showed that, N1 was stable for plant height panicle length, straw yield and protein content where as N2 was stable for traits like days to 50 per cent heading, culm diameter, days to maturity, grain yield, grain width and amylose content. N3 was stable for leaf length, days to 50 per cent heading and amylase activity where as N4 for leaf length and leaf width. The performance of N5 was stable for seedling height, plant height, panicle length, days to maturity, grain length and width, protein content, free amino acid content and amylose content while N6 was stable for ligule length, culm number, grain yield, 1000 grain weight, soluble carbohydrate content, free amino acid content and amylase activity. N7 had recorded stable performance for 1000 grain weight and soluble carbohydrate content. Biochemical characterisation indicated the possibility of utilising alcohol dehydrogenase polymorphism for identifying Njavara as a cultivar and also for identification of Njavara genotypes N1, N6 and N7. RAPD analysis of Njavara genotypes revealed good amplification with polymorphism for primers OPE 4, 6 and 16, OPP 7, 11, 12 and 19 and amplification with primers OPE 6, OPP 6 and OPP 11 exhibited unique bands for Njavara genotypes. The dendrogram drawn with two molecular markers viz., isozyme and RAPD revealed that the Njavara genotypes were grouped in one cluster whereas check varieties in another.
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    Major predators in rice ecosystems and their potential in rice pest management
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 2003) Premila, K S; Nalinakumari, T
    Survey conducted in three heterogeneous rice ecosystems of Kerala viz., Kuttanadu rice fields of Alappuzha district with high load of pesticide, double cropped rice fields of Thiruvananthapuram district with moderate level of pesticide and Pokkali rice fields of Ernakulam district with no pesticide during two consecutive seasons at the vegetative, tillering and reproductive stages of the crop revealed a distinct change in the composition and status of natural enemies and pests in rice ecosystem. While pests dominated in Kuttanadu and double cropped rice fields of Thiruvananthapuram, natural enerm es dominated In Pokkali ecosystem. Among the natural enemies, population of predators was signi ficantly higher 111 all the three ecosystems. Population of pnr as lt o i d s was very low. Among the predators, insect predators dominated the predator fauna followed by the spiders in the three ecosystems. The important insect predators observed were the mirid bug Cyrtorhinus livi dipennis Reuter and the coccinellid beetle Micraspis di scol or (Fabricius) and the major spider predators recorded were Tetragnatho maxillosa Thorell and Lycosa pseudoannulata (Boesenberg et Strand). Among the pests seen in th~ three ecosystems, the sucking pests were dominant followed by the defoliators. Stage specific sucking pests like the ricebug Lept ocorisa acut a (Thunb) and earhead thrips Hapl ot hrips ganglb aueri Schmutz too were seen infesting the crop during the respective crop stages. Hoppers were the predominant sucking pests in all the three rice ecosystems. Population of other sucking pests was very low. Among the hoppers Nephot ettix sp. and Sogatella furcifera (Horvath) were predominant. Comparatively, population of the brown planthopper, Nilaparvata lugens (Stal) was low. Population of other pests considered as major ones in the State like yellow stem borer Scirpophaga incertulas (Walker), gall fly Orseolia oryzae (Wood-Mason), case worm Parapoynx stagnalis Zeller etc. was negligible. The population of neutrals was low in all the three rice ecosystems. On the other hand, high population of these 'other insects' was seen in the adjoining vegetation. Greater diversity of arthropod spec ies was observed in the insecticide-free Pokkali rice ecosystem and insecticide-rationally-used double cropped rice ecosystem of Thiruvananthapuram. Less diversity of species was seen in Kuttanadu rice ecosystem where insecticides were applied indiscriminately. Studies on the suitability of different prey for mass culturing C. l ivi dip enni s, M. discolor, T. maxillosa and L. pseudoannulata under controlled conditions indicated that the best prey for C. lividipennis was the first instar nymphs of N. I ugens ,for M. discol or its eggs, for T. maxillosa, Nephotettix sp. and for L. pseudoannul at a, N. lugens. Efficiency of the predators 111 suppressing hopper pests when assessed in terms of searching capacity, feeding potential, prey preference and hyperpredation revealed that the insect predators C. lividipennis and M. discolor showed better ability to search for plant hoppers, especially N. lugens and S. furcifera. Comparatively, the searching capacity of the spiders for hoppers was low. The feeding potential and prey preference of C. livi dipenni s was significantly high for first instar nymphs of N. l ugens . Similarly, M. discolor preferred more of its own eggs than the other prey tested. The spider, L. ps eu do annul at a was observed to be a significantly better predator of hoppers than T. maxill os a. None of the predators tested showed cannibalism. Hyperpredatory activity was observed in Crocothemis sp., Agri ocne mis sp., Polytoxus fuscovitt at us (Stal), T. maxillosa, Oxyopes sp. and L. pseudoannulata. The mirid bug C. lividipennis was a highly preferred prey for hyperpredation. The commonly used insecticides for nee pest control viz., carbaryl, phosphamidon, monocrotophos, quinalphos and methyl parathion caused 80 to 100 per cent mortality of predators at the dose normally recommended for pest control. The results of the study emphasized the need for periodical assessment of the arthropod community Jl1 nee ecosystems as agro- ecological conditions tend to shift the status of phytophages and entomophages from time to time. Based on the results, growing of varieties tolerant to major pests and regulation of incident pests by conserving naturally occurring predators through optimal habitat modification and use of predator-friendly insecticides when absolutely needed will go a long way in sustainable production of rice in Kerala.
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    Nutritional resource use efficiency in rice production
    (Department of Agronomy, College of Horticulture, Vellanikkara, 2004) Vallal Kannan, S; John, P S
    The chemical constraints for higher yields in laterite soils are identified as low cation exchange capacity and organic matter content, high acidity, iron and aluminium toxicity, high phosphorous fixation and poor nutrient status. Investigations carried out to identify the limiting factors and their mode of action in laterite soil revealed direct effect of excess iron absorption, their metabolic interference, unfavourable Ca + Mg / K ratio, and deficiency of certain elements manifested as negative effects of some others. Management of organic manuring modified by amelioration with suitable amendments was reported to be an ideal remedial measure for reducing the above chemical constraints. An experiment was conducted at Agricultural Research Station, Mannuthy during 2001-2002, to characterize and quantify the effect of organic sources on nutrient supply, amelioration and inactivation of the deleterious factors in rice , culture and to study the supplementary requirements of inputs and complementary effects on yield improvement. It was also intended to develop a technology by integrating various inputs and their levels to ensure high resource use efficiency and consequently higher productivity. The plant height and tiller production was highest in the treatment green manure + lime + ash at active t.illering, panicle initiation and 50 per cent flowering. The total dry matter production was highest in the green manuring + lime and green manuring + lime + ash treatment. All the growth parameters such as plant height, tiller count and total dry matter production showed a stepwise improvement with doubling of K, doubling of K along with addition of lime and ash and doubling of K with addition of lime, ash and sulphur over the treatment where K was given at normal rate and without any ameliorants. The highest chlorophyll content both 'a' and ob' was found as resulted in the fallow - green leaf manure treatment, however, this was not reflected in the process of yield formation since the highest yield was observed for the treatment, green manure + lime + ash. The favourable cell sap pH around 6.21 was observed in the treatment green manure + lime + ash which resulted in the highest grain and straw yield. The highest grain and straw yield of 6.64 and 6.75 t ha-I, respectively was observed in the treatment combination green manure + lime + ash x N as NH4S04 + half P + lime + ash + double dose of K which indicate the importance of addition of lime, ash and sulphur as ammonium sulphate in the fertilizer package of rice in laterite soil. The following conclusionsare drawn from the results of the experiment. In the mundakan - summer - virippu rice cropping system in laterite soil leaving the land fallow' during summer may considerably reduce the yield during virippu if not supplemented with adequate organic manure and ameliorants like lime and ash. If the summer season is kept fallow, green leaf manu ring could be a better substitute for addition of organic matter to the laterite soil. Paddy straw incorporation at 15 days before the virippu cropping in laterite soil was found to reduce the yield of virippu rice probably due to high rate of immobilization ofN. The increase in acidity and consequent higher solubilization and uptake of Fe in virippu crop was evidently due to summer fallow which favour natural oxidation of Fe and Mn. Ameliorants like lime and ash added both during summer green manuring and virippu rice crop enhanced the rice growth and yield through modification of pH, supplementation of potash and calcium. Enhancement ofN:K ratio to 1: 1 was found to enhance rice productivity in laterite soil. Addition of K application did not increase the K content in the plant but reduced Fe uptake. Changing the N source to ammomum sulphate and thereby sulphur I fertilization was found to increase growth and yield of rice. Ammonium sulphate treatment helped mainly to increase plant height but not tiller production. Among yield attributes spikelet production was very much influenced by sulphur fertilization. The physiological and uptake efficiency of the N derived from green manuring was higher compared to other organic sources and consequently resulted in better agronomic efficiency. This indicates the need for a green manure - rice system in laterite soil to enhance soil and crop productivity. The green manured rice with ameliorants such as lime and ash, and ammonium sulphate as N and S source resulted in the highest net return and B:C ratio of2.25.
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    Participatory action research for renumerative rice production
    (Department of Agricultural extension, College of Horticulture, Vellanikkara, 2004) Parvathy, S; Ahamed, P
    As with the Complex, Diverse and Risk- prone (CDR) rice systems of many Asian countries, the Kerala state of peninsular India suffers from the fast depleting paddies and the ' high cost- low remuneration syndrome'. Crucial rice technologies have been blamed by stakeholders for the insensitivity to micro farming situations A multidisciplinary stakeholder Participatory Action Research (PAR) of emancipatory type and collaborative mode was done for three years (2001-2004) on identification and prioritization of constraints to profitable rice production to explore the available cost-reducing and productivity increasing technological options. The project focussed on screening of technological modules through farmer participatory field assessment and arrived at locally adaptable and remunerative technology packages. The project also developed and standardised an extrapolatable stakeholder participatory assessment model and protocol. The programme had a blend of extension approaches, research designs and tools like "ex-post facto", benchmark appraisal through Participatory Learning and Action (PLA), exploratory, diagnostic, evaluative, field experiments and analytical studies. The PAR was done in two rice ecosystems (irrigated and rainfe:l) of the midland, laterite belt of Kerala state, India. Fourteen technology modules were fitted into the PAR, under .. , each of the three treatments, viz., farmers' practice, recommended packages of the formal research system and location specific I technology components" jointly decided by the research team extensionists and farmers. Each technology component was subjected to five types of analysis viz., agronomic, statistical, economic, farmers perceptions and reactions, post-trial follow up analysis of adoption in the succeeding cropping seasons. The participatory interventions significantly influenced the level of technical knowledge and extent of adoption of adaptable technology modules, typifying the cognitive impact of an emancipating action research. The short duration red rice varieties "Kanchana" (Ptb 50) and "Kairali" (Ptb 49) proved to be the best first crop and second crop varieties respectively, to replace the ruling cultivars. The technology modules recommended by the formal research system viz., seed treatment with fungicides for the first crop season and Pseudomonas fluorescence for the second crop season were adaptable technologies. The PAR came out with an efficient planting density and crop geometry package (line transplanting; 15 x 10 cm; 67 . , hills/m'; 2-3 seedlings/hill) to replace the conventional planting system. The existing formal recommendations including IPM and INM practices could enhance and combat weeds, pest and diseases thereby enhancing crop yield. Harvesting with self- propelled reaper and threshing with mechanised thresher were cost effective, drudgery alleviating and time saving. The net result of the action research was a set of adaptable technological package for remunerative rice production in the CDR rice production systems. Cognitive and behavioural impact on the participants; and the standard methodology and protocol for participatory technology validation for rice in particular, and for any farm enterprise in general, with extrapolative effect.
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    Enhancing the productivity of the rice- fish/prawn farming system in pokkali lands
    (Department of Agronomy, College of Horticulture, Vellanikkara, 2004) Sasidharan, N K; Abraham, C T