Uso de silicato de potássio combinado com fungicida no controle da ferrugem da folha do trigo

Abstract

Alternative forms of plant disease control have been researched in order to reduce production costs and reduce environmental impact. Among them, the use of silicatebased products stands out. Silicon is able to increase the resistance of plants to attacks by insects, nematodes, bacteria and fungi. The use of silicate alone as well as in combination with fungicides can lead to a reduction of diseases caused by fungi in several cultivated plants. Thus, this work had as objective to evaluate the effect of potassium silicate combined with fungicides in the control of wheat leaf rust. The experiment was conducted in the experimental area of the Federal University of Pampa / Itaqui Campus. The experimental design was a randomized block design, with five treatments and four replications, the plots were 5 m x 4 m in size. Sowing occurred on June 27, using the cultivar Jadeite 11, at a density of 120 kg of ha-¹ seed and spacing of 0.17 m. The basic fertilization was done along with sowing with 350 kg ha-¹ of NPK in the commercial formula of 05-20-20. The treatments tested were: T1 control, T2 fungicide + fungicide, T3 silicate + silicate, T4 fungicide + silicate and T5 silicate + fungicide.The fungicide used was Nativo® (Trifloxystrobin Tebuconazole 0.6 L ha-¹) and potassium silicate (Supa Silica, Agrichem® 1.0 L ha-¹). The first application of the products occurred 65 days after sowing when the crop was in flowering, repeating the application 15 days after the first one. The evaluations of rust severity occurred weekly for 4 weeks, with 10 plants per plot being evaluated, evaluating flag leaf and whole plant. For the severity assessment, the diagrammatic COBB scale was used. In addition to the severity evaluation, productivity, hectoliter weight, thousand grain weight and number of grains per spike were evaluated. With this, it is possible to replace the second fungicide application with a potassium silicate application for the control of wheat leaf rust.