Crescimento inicial de mandioca submetida à aplicação de herbicidas em pós-emergência

The aim of this study was to evaluate the initial growth of cassava plants after post-emergence application of herbicides. The experiment was carried out in greenhouse, with randomized block design and four replications. Treatments consisted in the application of herbicides 25 days after crop emergence. The herbicides applied were bentazon, clomazone, fomesafen, fluazifop-p-buthyl, glyphosate, nicosulfuron, chlorimuron-ehtyl, sulfentrazone and the fluazifop-p-buthyl + fomesafen, and a treatment without herbicide application. The visual intoxication of cassava plants was evaluated at 7, 14, 21 and 28 days after herbicide application. Thirty-five days after application, we determined the height, stem diameter and dry matter of plants. Sulfentrazone and glyphosate caused the death of cassava. All herbicides caused reduction in stem dry matter, with the exception of fluazifop-p-buthyl. Chlorimuron-ethyl and nicosulfuron caused greater reduction of dry matter accumulation and crop leaf area. The application of herbicides bentazon, nicosulfuron and chlorimuron-ethyl reduced the stem diameter. It is possible to conclude that the herbicide application affected cassava growth, except for fluazifop-p-buthyl application.