Application of a mixture of five diazotrophs on sugarcane cultivated in the south of Brazil

Abstract

Sugarcane production in Brazil for the 2019/20 harvest is estimated at approximately 615 million tons. However, in the state of Rio Grande do Sul, it is estimated at only 42.5 thousand tons. It is assumed that the use of diazotrophic bacteria can contribute to the expansion of sugarcane cultivation in the state through increased productivity; hence, this study aimed to evaluate the effects of diazotrophs on the growth of sugarcane. The study was conducted using sugarcane varieties: RB867515, RB92579, RB966928, and RB975932 that were either treated with diazotrophic bacteria or left as a control. The application of diazotrophic bacteria resulted in increased leaf area and stem number in variety RB867515 (cane plant cultivation cycle), and an increase in the relative chlorophyll content of all the varieties of sugarcane except of RB92579. Furthermore, most varieties responded positively in terms of biomass, dry matter, total nitrogen, and soluble solids. These results suggest that the application of diazotrophs assists in the growth and development of sugarcane varieties in Rio Grande do Sul.