A statistical study of the experimental techniques used in the research services of the Ministry Of Agriculture

Abstract

In this study. data were re-analysed to detect possible sources of the high variation among the observations from completed field experiments. A method of analysis for block designs without any particular pattern was surveyed and various such block designs studied. Extensive work 8n the method of analysis (iterative analysis) have been done by Pearcb (1963, 1975, 19/6), Worthington (1975), Freeman (1975) and a slightly different version for missing plot techniques by Preece (1971). In this dissertation, emphasis has been laid on the shortcomings of the usual analysis when the designs are non-orthogonal (Kempthorne, 1978), existence and development of the iterative analysis (Corsten, 1958) as an alternative method of analysis employad in the study and rearrangement of plots into new blocks. Data from completed field trials were subjected to a post-mortem analysis to determine the block arrangement, plot and block shape, orientation and size which could have been more suitable to the experimental sites. It was also found that besides soil heterogeneity as a major source of variation, border effects could play an equally important rcle as a major source of variation in observations from field experiment.