Potencial da mistura de cinco bactérias diazotróficas no desenvolvimento e produção de cana-de-açúcar.

Abstract

It is believed that the application of diazotrophic bacteria can assist in the development of sugarcane resulting in increased productivity, in addition to contributing to the crop's tolerance to water deficit and improving its chemicalbromatological composition. Therefore, this work aimed to study the influence of a mixture of five species of diazotrophic bacteria on the development and production of sugarcane varieties. For this, four experiments were carried out with the specific objective of experiment: 1 -knowing the influence of the application of the mixture of diazotrophic bacteria and the use of different varieties on growth and productivity; experiment 2 - studying two varieties that stood out in the first experiment, together with three new sugarcane materials, in order to know the effects of adding the mixture on the growth of these varieties and their use in other experiments; experiment 3 - evaluate the influence of the mixture of bacteria in reducing the effects of water deficit; experiment 4 - test the hypothesis that the mixture may have an effect on production, maturation and also on the quality of plants, improving their characteristics for use in animal feed. The experiments were carried out in the field and in a greenhouse, in the 9th district of the city of Pelotas, located in Rio Grande do Sul, Brazil. The results obtained indicate that the application of the mixture in sugarcane plants promotes significant increases in important characteristics, such as plant height, stem diameter, nitrogen content, total soluble solids, anticipating maturation, productivity and mass increase dry. In addition, it provides an increase in net carbon assimilation, chlorophyll content and osmotic potential. Maintains stomatal conductance and relative water content in leaves, decreases the liquid transpiration of plants in situations of water deficit and positively influences chlorophyll fluorescence parameters, increasing the maximum quantum efficiency of FSII, the effective photochemical quantum yield of FSII a photochemical dissipation and electron transport rate, which contributes to reducing the effects of water deficit. It can also improve the chemical-chemical composition of plants for use in animal feed, decreasing the amount of lignin, cellulose and fiber in neuter and acid detergent.