Fig. 7. Effect of ultraviolet-B (UVB) radiation on biomass of seedlings of an F₁ population of Italian ryegrass surviving treatment with different doses of diclofop-methyl. Parental and F₁ populations were exposed to the same UVB light and herbicide environments. Bars represent means ± standard errors. Analysis of variance: UVB light (L), P = 0.0034; herbicide dose (D), P = 0.0007; L x D, P = 0.31.