The objective of work was to evaluate the selectivity of the s-metolachlor herbicide to dry bean cultivars (Phaseolus vulgaris L.), through evaluations accomplished in growth chamber. The treatments consisted of the combinations of six dry bean cultivars (Carioca, Rudá, Pérola, Jalo Precoce, Vermelho 2157 and Xamego) and seven doses of s-metolachlor (0.00; 0.48; 0.96; 1.44; 1.92; 2.88 and 3.84 kg/ha). It was verified that the only cultivar that didn't show decrease of the plant height with the increase of s-metolachlor doses was Pérola, and that Vermelho 2157 cultivar was the most sensitive. The only cultivar that showed reduction of the dry matter of the aerial part of plants with the application of increasing doses of s-metolachlor was the Carioca. Carioca and Jalo Precoce cultivars were susceptible to s-metolachlor, regarding the reduction of the roots dry matter. However, the largest reduction in this characteristic was observed in Carioca. The level of visual symptoms of toxicity increased for all cultivars with the increase of doses. The Carioca and Vermelho 2157 were the most sensitive to action of s-metolachlor, presenting, respectively, increase of 22.0 and 21.1% in the injuries of plants at 30 days after the planting, to each 1 kg/ha of s-metolachlor applied. The cultivars more selective to the s-metolachlor with regard to the toxicity symptoms were Pérola and Jalo Precoce.
herbicide; tolerance; toxicity
