CHI-SQUARE TEST COMPARISON BETWEEN TREATMENT MEANS COMPETITION EFFECTS COVARIANCE ANALYSIS ELEMENTS OF EXPERIMENTATION Field ecperiments MECHANICAL ERRORS Mathematical Statistics PRESENTATION RESEARCH RESULT PROBLEM DATA 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