Desenvolvimento vegetativo de cana-de-açúcar sob a fixação biológica em associação de algas no brejo paraibano

Abstract

Sugarcane (Saccharum officinarum L.) is one of the most cultivated crops in Brazil, raw material for various products, such as sugar, ethanol and derivatives. Due to the high demand for nitrogen fertilizers, it is necessary to search for alternatives that improve its development, such as the use of bacteria, such as Azospirillum brasiliense, due to its good ability to fix nitrogen. Thus, the objective of this work was to evaluate the vegetative development of sugarcane in response to biological nitrogen fixation. The research was carried out at the Chã de Jardim Experimental Farm, of the CCA/UFPB, Areia-PB, during a year in the plant cane stage. The design was randomized blocks with four replications and seven treatments, which were: control, inoculation, inoculation plus 50% N, fertilization with 100% N, inoculation plus algae fertilizer, algae fertilizer plus 50% N and inoculation plus algae fertilizer plus 50% N. Planting was carried out at a density of twelve buds per meter with spacing of 1.20 m between furrows. Inoculation was carried out in the furrow and topdressing fertilizations with nitrogen were carried out in two stages in topdressing. The variety used was RB041443 launched a few years ago, the stem height, leaf length, leaf width, stem diameter, number of internodes, number of leaves and plant per linear meter were evaluated. Data were tabulated and processed by R software, submitted to analysis of variance, Tukey test and principal component analysis. There was no influence of treatments on the analyzed variables, except for leaf width, which despite the statistical difference did not influence the development of sugarcane variety RB041443. The application of algae-based Lithothamnium fertilizer did not significantly influence the action of bacteria in order to improve vegetative development.