This work was carried out in field conditions with the objective of evaluating residual activity of herbicides recommended to sugarcane crop, when applied to the soil in the dry season. Treatments were organized according to split-plot scheme, where six herbicides were applied to the plots and three periods of product permanence in the soil (130 days, 70 days and control without application) were placed in the split-plots. Herbicide treatments were (g ha-1): amicarbazone at 1260; clomazone at 1250; hexazinone at 450; imazapic at 147; isoxaflutole at 187.5; and sulfentrazone at 900. Besides the natural weed community, cucumber, considered as bioindicator, was sown in the area for the evaluation of the product residual activity. The same herbicide molecule had different evaluation as a function of the species. The herbicides amicarbazone, hexazinone, isoxaflutole and sulfentrazone show positive properties for soil application in the dry season, such as high solubility, low Kow and low photodegradation. Pre-emergence application of imazapic had consistent efficacy in the dry season, controlling satisfactorily the cucumber and the natural weed community. Clomazone did not control the cucumber and the weed natural community.
sugarcane; pre-emergence; persistence; residue
