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Theses

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1984 - 19865
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Subject: Statistics × End date: 1986 × Start date: 1984 × Thesis Type: M.Sc ×
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Now showing 1 - 5 of 5
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    ThesisItemOpen Access
    Comparative study of lactation curves in cattle
    (Department of Statistics, College of Veterinary & Animal Sciences, Mannuthy, 1985) Mathew Sebastian; KAU; George, K C
    An investigation, based on 174 normal lactation records of 93 Jersey crossbred cows and 90 normal Isolation records of 55 Brown Swiss crossbred cows belonged to the University Livestock Farm, Mannuthy, was undertaken : (1) to compare the relative efficiency of various isolation curve models and to select the best one (ii) to compare the two genetic groups based on order of Isolation and season of calving and (iii) to develop equations for predicting total milk yield from part yields. Records upto the 4th Isolation were included in the study. The observations spread over a period of six years from 1978 to 1983. The year was delinested into dry, rainy and moderate seasons.
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    ThesisItemOpen Access
    Assessment of genetic divergence by factor analysis in groundnut (Arachis hypogaea L.)
    (Department of Statistics, College of Veterinary & Animal Sciences, Mannuthy, 1986) Muralidharan, K; KAU; Saraswathi, P
    Factor analysis, Principal component analysis, discriminent analysis, and cluster analysis were carried out with a multivariate data on 30 characters of 62 bunch type groundnut varieties grown in upland during khariff 1982 and rice fallows during summer 1982. Vegetative, reproductive and growth factors were identified as the causative factors of genetic divergence in both the environments. A height factor was also found to work with rice fallows. The characters which were most amenable to change due to selection in these factors were identified. They were not found to agree with the results obtained from discriminant analysis. When factor loadings were estimated from principal components, clustering of characters were found identical to those obtained from factor analysis.
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    ThesisItemOpen Access
    Comparison of different techniques for the estimation of genotype-environment interaction
    (Department of Statistics, College of Veterinary & Animal Sciences, Mannuthy, 1984) Laly John, C; KAU; Gopinathan Unnithan, V K
    The genotypic stability analyses of Eberhart and Russell (1966), Perkins and Jinks (1968), Freeman and Perkins (1971), Wricke (1966) and Shukla (1972) were studied in detail. The mistakes in the analysis of variance of Perkins and Jinks (1968) were corrected. The first three analyses which used the theory of regression explains a large part of the genotypic environment interaction. On the otherhand, when the regression cannot explain a large part of the genotype - environment interaction, Wrioke's ecovalence ratio and Shukla's stability variance could satisfactorily be used.
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    ThesisItemOpen Access
    Optimum plot size for field experiments on turmeric (Curcuma longa L)
    (Department of Statistics, College of Veterinary & Animal Sciences, Mannuthy, 1984) Gopakumaran Nair, B; KAU; Prabhakaran, P V
    A uniformity trial on turmeric (Curcuma Longa. L.) was conducted at the experimental field of College of Horticulture, Vellanikkara, during the period from June 1983 to January 1984 to assess the nature and magnitude of soil heterogeneity of the experimental field, and to determine the optimum size and shape of experimental plots and blocks in conducting field trials on turmeric by different methods. At the time of harvest, the yield data from 864 plots each of size 0.6m x 0.75m were recorded separately, discarding the external border row.
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    ThesisItemOpen Access
    Pre-harvest forecasting of sugarcane yield
    (Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1984) Alphi Korath; KAU; Prabhakaran, P V
    Several yield prediction models were tried to examine their suitability for the pre-harvest prediction of yield of two varieties of sugarcane namely CO-997 and CO-62175 in different months of plant growth using biometric characters based on the data collected from the Sugarcane Research Station, Thiruvalla. The methods of multiple regression analysis, path coefficient analysis and principal component analysis were used for the above purpose. Multiple regression analysis using plant biometric characters revealed that cane yield could be predicted on the basis of observations on height of the cane, girth of the cane find estimated total leaf area per cane or area of third leaf from the seventh month after planting onwards with an accuracy in the range of 59*5 to 81.9 per cent. The estimated cane yield when multiplied by the number of canes in the plot will give an advance estimate of the plot yield Linear models with five biometric characters viz., height of the cane, girth of the cane, width of the third leaf determined from the selected plants of each plot and number of canes/tillers and number of leaves determined on a whole plot basis were sufficient to predict the plot yield of the crop as early as in the fifth month of plant growth with an accuracy in the range 68 to 90 per cent. Path analysis revealed that height of the cane and girth of the cane were the t wo important characters contributing towards cane yield in all stages of plant growth. Using the forecasting models fitted with principal components as explanatory variables, yield could effectively be predicted with 81.4. per cent accuracy for variety CO-997 and with 76 per cent accuracy for variety 00-62175 in the Sixth month of plant growth.