Uso da microbiolização de sementes de trigo com isolado de Bacillus sp. no crescimento de plantas e incidência de doenças

Abstract

Because of its food importance, wheat is one of the most widely cultivated cereals in the world, serving for thousands of years as a source of calories and one of the main raw materials in the generation of food. However, the culture is limited by numerous factors that affect productivity, among these factors are the incidence of foliar diseases commonly found in our region. An alternative to solve this problem is through biological control with the use of microorganisms such as the genus Bacillus sp. which is gaining more and more attention, due to its capacity of biocontrol and disease and growth promotion of plants. Therefore, this work aimed to evaluate the effect of microbiolization with prokaryotes of Bacillus sp on the severity of leaf diseases and plant growth, as well as some yield variables in wheat crop. For this purpose, an experiment was conducted in a rural property in the countryside of the municipality of Guarani das Missões - RS during the months of June to November 2019, in a 4x2 factorial scheme (different concentrations of the bacterial isolate x cultivars) with four repetitions, in the experimental design Randomized Blocks. Two wheat cultivars BRS TARUMÃ and BRS PASTOREIO were microbiolized with three different concentrations of the bacterial isolate LABMID UFFS RD 34 (Bacillus sp) belonging to the collection of the Integrated Disease Management Laboratory (LABMID UFFS) and also a control treatment with saline solution only. Weekly evaluations of the severity of Leaf Rust and Yellow Spot were performed for subsequent calculation of the area under the disease progress curve (AACPD), and also plant measurements to determine the growth rate, final plant height, number of tillers, mass of one thousand grains, and productivity were also evaluated. The concentration of 0.5 nm showed satisfactory results in reducing the severity of Rust, while for Stain the concentration of 0.75 nm stood out. The concentrations showed little influence on plant growth, with more significant results only in the stage of elongation of the culture, but with an effect on plant height. The concentrations did not influence the number of tillers per plant, but positively influenced the mass of one thousand grains and the productivity. More significant effects were observed when analyzing the cultivars among themselves where BRS PASTOREIO in comparison to BRS TARUMÃ showed lower values for disease severity, and higher values for growth rate, mass of one thousand grains, tillers per plant, plant height, and productivity.