Respostas fisiológicas e agronômicas da cultura de batata-doce desenvolvida para produção de etanol em função da aplicação de herbicidas

Abstract

The objective of this work was to evaluate the physiological and agronomic effects of post-emergent herbicides on sweet potato crop. The experiment was conducted in the LASPER experimental area of the Federal University of Tocantins, Palmas campus. Two experiments were set up: in the field and in pots. In the field experiment, a randomized complete block design (DBC) with one cultivar (Duda) was used, five treatments being: control (weed), atrazine + S-metolachlor (3,5 L.ha-1), nicosulfuron , 25 f.ha-1), fomesafem + fluazifop (1.8 L.ha-1 + 1 L.ha-1) and carfentrazone (0.75 L.ha-1) and four replicates. For the experiment in pots, to the physiological analyzes, the factorial design was 5x3 being: five treatments and three times (14, 21 and 27 DAA) with three replications; for the agronomic analysis in pots, the experiment was designed in the field. The means of the treatments were compared by the Tukey test at 5% probability. It was observed that herbicide treatments significantly reduced to US, A, Ci in the periods of 24 and 48 HAA, whereas only treatment with carfetrazone dramatically reduced E and gs to 24 HAA in approximately 73 and 88% , respectively, relative to the control. The treatment atrazine + S-metolachlor did not differentiate from the control, for most agronomic parameters evaluated, mainly, Productivity (70.1 ton.ha-1); (17.72%) and ethanol productivity (6,554 L.ha-1), showing that this herbicide can be used with selective potential for sweet potato crop in control of broad-leaved plants in application postemergence