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Theses

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1980 - 19818
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Subject: Agriculture × Author: KAU × End date: 1981 × Start date: 1980 ×
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Now showing 1 - 8 of 8
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    ThesisItemOpen Access
    Estimation of genetic parameters in green gram (Phaseolus aureus Roxb.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Presanna Kumari, K T; KAU; Mary, K George
    Biometric studies on fifteen divergent green gram varieties (Phaseolus aurreus Roxb. syn. Vigna radiata (L.) wilzeck.) was conducted at the College of Agriculture , Vellayani , during November- January, 1979-80, to estimate the important genetic parameters like mean, range, genotypic and phenotypic coefficientsof variation , heritability, genetic advance and genetic gain and to find out the direct and indirect contributions of various component characters on yield by path coefficient analysis. There were significant differences among the varieties for all characters studied. Genotypic coefficient of variation was maximum for number of branches per plant followed by 100 seed weight and minimum for days to 50 per cent flowering . High heritability estimates were observed for pod length , 100 seed weight, plant height, number of seeds per pod days to 50 per cent flowering and number of pods per plant. Genetic gain was maximum for number of branches per plant followedby 100 seed weight and minimum for days to 50 per cent flowering. The number of branches per plant 100 seed weight, number of pods per plant and pod length had high heritability and genetic gain indicating the presence of additive gene action and hence they can be relied upon in selection programmes.
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    ThesisItemOpen Access
    Studies on heterosis and combining abilities with respect to important economic traits in Capsicum annuum, L.
    (Division of Agricultural Botany, College of Agriculture, Vellayani, 1981) Manikantan Nair, P; KAU; Mary, K George
    Sixty three varieties of Capsicum annuum representing different agroclimatic regions of the country constituted the base material of the study. Based on yield potential , adaptability and tolerance to leaf curl complex disease, thirty varieties were selected for subsequent studies. Comprehensive genetic studies including estimation of genetic parameters, cause effect relationship by path coefficient analysis, genetic divergence by Mahalanoble D2 statistic and a nine parent diallel analysis to causes the combining ability, to unravel the pattern of inheritance and also to examine the level of heterosis manifested with respect to eighteen economic characters including four nutritiveand quality attributes namely Vitamin A, Vitamin C, Capsaicin and Oleoresin content were conducted during the year 1976-79. Analysis of plot means exhibited highly significant differences among varieties except for Capsaicin content. The high degres of variability in economic attributes offers scope for recombining desirable genes from different varieties.
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    ThesisItemOpen Access
    Effect of herbicides of cell division sterility and yield in rice
    (Division of Agricultural Botany, College of Agriculture, Vellayani, 1981) Kishore Kumar, K; KAU; Mercy, S T
    Herbicides have become a very important tool for weed control and research in this line has been progressing ever since their invention. Studies on the possible damages which herbicides cause at the chromosomal level have been undertaken under laboratory conditions by many workers. But only a few studies have been on this aspect under field conditions. This study was done with the aim of finding the extent of chromosomal aberrations and consequent deterioration of yield attributes in rice caused by the application of five selective herbicides. Observations on the herbicidal influence on weed population have also been taken. From this study it has been found that herbicides do cause chromosomal changes during cell division. Pollen mother cell studies revealed that highest number of chromosomal abnormalities occur in 2,4-D and nitrofen treatments when applied at a dose of 1kg and 1.5 kg a.i. per hectare, eighteen days after transplanting. Such abnormalities caused pollen sterilityand consequent spikelet sterility leading to reduction in yield . These parameters showed significant positive correlation.
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    ThesisItemOpen Access
    Induction of mutations in cowpea (Vigna unguiculata (L.) Walp.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Sunny, K Oommen; KAU; Gopimony, R
    Studies were undertaken to obtain precise information on the effects of six doses of gamma rays (5-30 krads) and seven concentrations of ethyl methanesulphonate (0.1-0.7 per cent) in cowpea, using the variety ' New Era'. The effectiveness and efficiency of different doses of the two mutagens in inducing chlorophyll mutations were estimated. (1) The germination of cowpea seeds was not affected by green rays even at the highest dose employed , whereas ethyl methanesulphonate inhibited germination and the reduction in percentage was progressive with increasing doses. (2) The survival of plants based on the number of seeds sown was reduced by both mutagens. Post germination mortality occured to a certain degree with gamma irrediation, whereas it did not occur to any considerable extent with ethyl methanesulphonate treatment. (3) A differential effect on the growth of shoot and that of root was observed with both mutagens in the present study. The growth inhibition was more for the shoot with gamma rays ,while ethyl methanesulphonate produced a higher degree of inhibition for the growth of root than for shoot.
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    ThesisItemOpen Access
    Selection parameters in tapioca (Manihot esculenta Crantz)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Radhakrishnan, V V; KAU; Gopakumar, K
    During a biometrical study conducted on 20 divergent types of tapioca (Manihot esculenta Crantz) in the premises of Central Tuber Crops Research Institute at Trivandrum, as a postgraduate programme of the Kerala Agricultural University, useful informations on the selection parameters become available. Accordingly, it was found that harvest index should be the best reliable criterion for effecting selection in favour of a desirable genotype from among others in a genetically heterogenic base population. Further, it is proposed that potentially high tuber yielders in the crop could be identified among relatively short statured ones with more number of large sized leaves that have become completely developed sufficiently early during development of the shoot. In addition , a tendency for relatively more number of leaves to become abscissed towards the time of harvest should also be considered as a positive sign of high tuber yield
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    ThesisItemOpen Access
    Selection index in horse gram (Dolichos biflorus L.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Suraiya, D; KAU; Mercy, S T
    The present biometric study was carried out in the College of Agriculture, Vellayani during the year 1979-80 with fifteen varieties of horse gram (Doliches biflorus L.) to formulate a suitable selection index for yield. The observation plants were studied individually for the following characters. (1) Seed yield per plant (2) Number of pods per plant (3) Number of seeds per pod (4) 100-seed weight (5) Pod length (6) Days to 500 flowering (7) Height of plant (8) Number of branches (9) Days to maturity (duration). The data obtained in the study were subjected to statistical analysis viz. estimates of mean for all the different varieties, analysis of variance in respect of the nine selected characters, estimates of components of variances, genotype, environmental and phenotypic coefficients of variations, heritability, genetic advance and studies of discriminant function and path coefficient analysis.
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    ThesisItemOpen Access
    Studies on intervarietal hybrids in cowpea
    (Division of Agricultural Botany, College of Horticulture, Vellanikkara, 1980) Inasi, K A; KAU; Narayanan Namboodiri, K M
    Among the green vegetables cultivated in Kerala, cowpea (Vigna ungulculata L.) occupies about 70 per cent of the total area. At present cowpea cultivation in the state is showing a declining trend due to the low productivity of the available local varieties. The highly contrasting systems of cultivation of cowpea in the various parts and in different seasons in the State compels compels cowpea breeders to evolve varieties of different combinations of plant, pod and seed characters. This is possible by combining of desirable characteristics found distributed in different varieties, through hybridisation followed by selection.
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    ThesisItemOpen Access
    Genotype environment interaction in selected hybrid lines of sweet potato (Ipomoea batatas (L.) Lam.)
    (Department of Agricultural Botany, College of Agriculture, Vellayani, 1980) Ibrahim, K K; KAU; Mary, K George