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19863
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Subject: Statistics × End date: 1986 × Start date: 1986 × Type: Thesis ×
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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
    Forecasting of rice yield using climatological variables
    (Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1986) Ajitha, T K; KAU; Prabhakaran, P V
    Systematic crop and weather observations on autumn and winter paddy at Pattambi Rice Research Station, during 1949-50 to 1973-74 have been analysed in order to evaluate the effect of different climatic factors on rice yield and to develop suitable prediction models for the preharvest forecasting of rice yield with sufficient degree of precision. The varieties under observation were PTB 1 and PTB 5 in the autumn season and PTB 12 and PTB 20 in the winter season. The crop was raised as rainfed through out the entire period of investigation. The moteorological variables included in the study were total rainfall (mm), number of rainy days, maximum temperature (°C), minimum temperature (°C), maximum humidity (%), minimum humidity (%), total hours of sunshine and wind velocity (km/h).
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    ThesisItemOpen Access
    Uniformity trials on colocasia (Colocasia esculenta L.)
    (Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1986) Lizy, M J; KAU; George, K G
    A uniformity trial on colocasia was conducted at the experimental field of the College of Agriculture, Vellayani during the period April – September 1984, to study the nature and magnitude of soil heterogeneity and to estimate the optimum size and shape of plots in conducting field trials on colocasia. The various techniques adopted for achieving these objectives were, productivity contour map, mean squares among strips, serial correlation, heterogeneity index method and maximum curvature method. The biometrical observations such as height, girth, yield number of leaves and leaf area were taken from all plants. Productivity contour map revealed that the field was heterogeneous with regard to soil fertility. The mean squares for the horizontal and vertical arrangements indicated that the fertility was more clear along the length than along the width of the field. The low serial correlation coefficients for both rows and columns established that fertile areas occur in patches. The coefficient of variation increased in plot size. For a given size of the plot, the long and narrow plots yield lower coefficient of variation than square plots. The Smith’s variance law in the form Y = ax-b gave a satisfactory fit to the data. But among all the fitted models the equation Y = a + b/ x1/2 + c/x was found to be the best. Generalisation of Smith’s law in the form Y = ar-g 1c-g 2 also gave a good fit to the data and heterogeneity of rows was found to be significantly more than that of columns. The optimum plot size found out by using Smith’s equation was 12 units (3.34m2). But the optimum plot size computed by using the optimum equation Y = a + b/x1/2 + c/x was 10.87 units (2.93m2). A study of the optimum plot size while considering the cost of experimentation using the Smith’s equation was 1.636m2. In general, it can be recommended that a plot of 2.93m2 as optimum for conducting field trials on colocasia.