Tratamento de sementes e fungicidas foliares no controle da ferrugem e da mancha amarela e sobre variáveis de rendimento em trigo

Abstract

Wheat is one of the most important crops, being one of the main cereals used in human food. However, there are several factors that can negatively influence its productivity, being among the main diseases such as leaf rust and wheat yellow spot. As a means of control, we opt for the use of seed treatment, as well as the use of fungicides in foliar sprays. The objective of this work was to evaluate the use of chemical and biological treatment of wheat seeds, associated or not with the fungicide use on shoot, on the control of rust and yellow spot and on yield variables. The experiment was conducted between June to November 2016, in the experimental area at Universidade Federal da Fronteira Sul, campus Cerro Largo. The experiment was conducted in a 5x4 factorial scheme (treatment of seeds x fungicides in foliar applications) with 4 replicates. The experimental design was randomized blocks (DBC) in sub divided plots. The treatments used were the base of Trichoderma harzianum, Trichoderma asperellum, Trichoderma spp., Triadimenol in addition to a control (without treatment), these being combined with the application of Azoxystrobin + Propiconazol (62.5 + 62.5 g ia ha-1); Azoxystrobin + Ciproconazol (60 + 24 g i.a. ha-1); Azoxystrobin + Tebuconazol (48 + 96 g i.a. ha-1) and Witness (no application). Emergency evaluations, number of tillers, yellow spot and wheat leaf rust severity and crop yield components were performed. The results were submitted to analysis of variance and the means were compared by the Tukey test at 5% of error probability. It was possible to conclude that the use of seed treatment associated with the use of fungicides acts to control wheat leaf rust; the best control of the yellow spot can be attributed to the use of Azoxystrobin + Propiconazol, which was also responsible for presenting the best values of hectoliter weight and spike size. Other evaluations did not show significant differences in relation to the treatments used.