Weed-crop competition models and response-surface analysis of red rice competition in cultivated rice: a review

Models that predict crop yield based on crop and weed densities are valuable for estimating yield losses and devising weed control strategies. Field experiments were conducted in 1987 and 1989 to evaluate a model describing the competitive interaction between red rice (Oryza sativa L.), a weedy variety, and the commercial cultivar, Mars. The response-surface model consisted of nonlinear yield-density equations where average per-plant yield was the dependent variable and the densities of the competing plant varieties were the independent variables