Fig. 5. The effect of ultraviolet-B (UVB) light on the density-dependent production of reproductive biomass in (A) nontreated (control) plots and (B) herbicide-treated plots. Parental and F₁ populations were pooled for analysis. Regression model fitted: y = a exp(–Kx). Parameters for (A) UVB–: a = 0.061, K = 0.017 (SE = 0.01), R² = 0.88; UVB+: a = 0.045, K = 0.014 (SE = 0.004), R² = 0.97; parameters for (B) UVB–: a = 0.18, K = 0.12 (SE= 0.055), R² = 0.47; UVB+: not significant.