With the purpose of evaluating the splitting of the dose of oxyfluorfen and ioxynyloctanoato on the tolerance of the 'Granex 33' onion plants and the efficiency on the weed control at crop, installed by direct sowing, two experiment were carried out, one in the presence and the other in the absence of weeds. Ioxynyloctanoato, when applied in doses higher than 0.125 kg/ha, at 19 DAS, was less selective for the 'Granex 33' cultivar than oxyfluorfen. Splitting of the doses, up to three applications, increased the tolerance of onion plants toward both oxyfluorfen and ioxynyl-octanoato. Oxyfluorfen, at the evaluated doses, controlled Galinsoga parviflora and Amaranthus hybridus; however it did not control Lepidium virginicum and Coronopus didymus. Ioxynyl-octanoato at 0.125 kg/ha, at 19 DAS, plus two applications of 0.25 kg/ha at 34 and 65 DAS, controlled the existing weeds, with production of bulbs similar to the hand-hold control. None of the herbicides influenced the bulbs post-harvest conservation up to 120 days of storage.
Allium cepa; weed; herbicide; control; tolerance