Statistical Adjustment of Maize Grain Yield for Sub-Optimal Plot Stands

SummaryLinear covariance analysis of crop yield data using plot stand as the covariate is not satisfactory when the missing plants are eliminated before maturity. This is because the resulting relationship between yield and plot stand is non-linear. In this paper, a transformation of plot yield data to adjust for sub-optimal stands in circumstances involving interplant competition is examined. A biomathematical derivation and interpretation of the proposed model is provided. An experiment involving two varieties of maize (Zea mays) grown at three locations provided the data used to validate the model. Adjusted genotype mean yield values obtained using the proposed exponential transformation were in agreement with observed values.