Browsing by Author "Lizy, M J"

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Comparison of different models for the determination of optimum plot size for colocasia (Colocasia esculenta L.)
(Kerala Agricultural University, 1988) Lizy, M J; George, K C; Jocob Thomas, M
Comparison of different statistical techniques for assessing soil heterogeneity
(Kerala Agricultural University, 1988) Lizy, M J; George, K C; Jacob Thomas, M
A uniformity trial on colocasia was conducted at the College of Agriculture, Vellayani, Kerala Agricultural University, during kharif 1984. Biometrical observations on 16 characters as indicated in Tables 1,2 and 3 were taken from all plants. The nature of soil heterogeneity was studied from the productivity contour map. The map revealed that the field could be considered heterogeneous in nature. Based on the mean square analysis, we could not predict any general trend of fertilty variation existing in the field. The low serial correlation coefficients established that fertile areas occur in patches. The'b' value was found higher for yield than for other characters. While comparing all the four methods we could assume that the method of serial correlation, is more reliable than all other methods.
Optimum size and shape of plots under colocasia (Colocasia esculent A L.)
(Kerala Agricultural University, 1987) Lizy, M J; George, K C; Jacob Thomas, M
A uniformity trial on colocasia was conducted at the experimental field of the College of Agriculture, Vellayani, Kerala during April-September, 1984. At the time of harvest the observations regarding the yield characteristics were recorded. From the study of the size and shape of the plot it was found that an increase in plot size in either direction decreased the coefficient of variation. For a given size of the plot, the best shape was that having more number of rows than columns. The heterogeneity coefficient b in the Smith's equation for yield was 0.6057. The optimum plot size found out by maximum curvature method and by modified maximum curvature method was approximately 3 m2. When the cost of experimentation was considered, a plot size of 1.636 m2 was found optimum for conducting experiments with colocasia.
Uniformity trials on colocasia (Colocasia esculenta L.)
(Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1986) Lizy, M J; 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.