HERBICIDAS APLICADOS NA DESSECAÇÃO DE CAPIMAMARGOSO INTERFEREM NA GERMINAÇÃO DAS SEMENTES?

Abstract

Bitter grass is one of the main weeds, due to its competitive characteristics with cultivated crops and selection of glyphosate and biotype resistant biotypes. This work aimed to evaluate the effect of herbicide application on desiccation on the germination of bitter grass seeds. The experiment was conducted at the Instituto Federal Goiano Campus Urutaí, in a completely randomized design (DIC) in a double factorial scheme with an additional factor, with four replications. The treatments consisted of seeds from an area infested with bitter grass after treatment with a combination of glyphosate with the graminicides clethodim and haloxyfop. The glyphosate dose was standard at 1080 g i.a. ha-1 for all treatments, and two doses of clethodim (192, 240 g i.a.ha-1 ) and haloxyfop (120, 240 g i.a. ha-1 ), in addition to three mixtures with nitrogen additives: urea (5 g L -1 ), ammonium sulfate (15 g L -1 ) and urea + ammonium sulfate (2.5 + 7.5 g L -1 , respectively). After 28 days of application, 20 panicles of bitter grass were collected from each treatment to evaluate germination, through the germination test. The data were submitted to analysis of variance by the “F” test at 5% probability. Ammonium sulfate was the nitrogen additive that most potentiated the effect of the herbicides, haloxyfop at a dose of 120 g i.a.ha-1 , both in the absence of nitrogen and associated with urea, presented the lowest germination control indexes of the Digitaria insularis seeds. The other herbicides applied in the desiccation, prevented the germination of the seeds of bitter grass.