Agriculture- Research- statistical methods CHI-SQUARE TEST COMPARISON BETWEEN TREATMENT MEANS COMPETITION EFFECTS COVARIANCE ANALYSIS ELEMENTS OF EXPERIMENTATION MECHANICAL ERRORS Mathematical Statistics PRESENTATION RESEARCH RESULT PROBLEM DATA Rice- Research- statistical methods SINGLE, TWO AND THREE OR MORE EXPERIMENTS SOIL HETEROGENEITY Single Factor Experiments, Two-Factor Experiments, Alternative Designs, Data Analysis, Regression Analysis, Correlation Analysis, Covariance Analysis, Chi-square test, Soil Herterogenity, Mechanical Errors