Atividade residual de herbicidas pré-emergentes aplicados na cultura da soja sobre o milheto cultivado em sucessão

-1 ), diclosulam (0,035 kg ha-1), sulfentrazone (0,600 kg ha-1) e flumioxazin (0,050 kg ha-1) e uma testemunha, aplicados logo apos a semeadura do cultivar de soja Msoy-6101. Nas subparcelas, realizou-se a semeadura do milheto, cultivar ADR-7010, em quatro periodos, correspondendo a 0, 40, 80 e 120 dias apos a aplicacao dos herbicidas (DAA). Durante a conducao do ensaio, foram determinados os niveis de intoxicacao, estande, altura e massa seca da parte aerea das plantas de milheto. No final do ciclo foi avaliado o rendimento de graos da cultura. O hibrido de milheto ADR-7010 apresentou elevada sensibilidade com relacao a atividade residual dos herbicidas sulfentrazone, diclosulam e imazaquin quando cultivado logo apos a aplicacao destes. A bioatividade dos herbicidas imazaquin, diclosulam e flumioxazin nao foi suficiente para alterar o rendimento de graos do milheto cultivado em sucessao a soja (120 DAA), mostrando que esse intervalo de tempo e suficiente para dissipacao desses herbicidas. Dos herbicidas pre-emergentes avaliados, o sulfentrazone apresentou maior atividade residual, influenciado negativamente o rendimento da cultura durante o intervalo de tempo estudado. Palavras-chave: carryover, sulfentrazone, diclosulam, imazaquin, flumioxazin, Pennisetum glaucum. ABSTRACT - The objective of this study was to evaluate the persistence of herbicides applied in pre-emergence in soybean crop and the effects of these herbicides on pearl millet grown in succession. The herbicides imazaquin (0.160 kg ha-1), diclosulam (0.035 kg ha-1), sulfentrazone (0.600 kg ha-1), and fumioxazin (0.050 kg ha-1) were used immediately after sowing of soybean Msoy-6101, in plots of 80 m2, divided into sub-plots of 20 m2 (5 x 4 m). A randomized block design with four replications was used in a split-plot scheme 5 x 4. In the sub-plots, pearl millet hybrid ADR-7010 was sown in four periods after herbicide application, corresponding to 0, 40, 80 and 120 days after herbicide application (DAA). Pear millet injury, stand, height and dry biomass of the plant were evaluated at 7, 15, and 28 days after emergence; crop grain yield was evaluated at the end of the cycle. Pearl millet hybrid ADR-7010 showed high sensitivity to the residual activity of sulfentrazone, imazaquin, and diclosulam when grown immediately after herbicide application. The bioactivity of imazaquin, diclosulam, and flumioxazin was not sufficient to affect grain yield of millet grown after soybean (120 DAA), suggesting that this interval is sufficiently long for dissipation of these herbicides. Among the pre-emergent herbicides, sulfentrazone showed longer residual activity, negatively influencing the crop's yield during the time interval studied.