Associative diazotrophic bacteria inoculated in sugarcane cultivars: implications on morphophysiological attributes and plant nutrition

ABSTRACT Sugarcane is one of the first activities of economic importance in Brazil. The understanding of the nutritional dynamics at different phenological stages of the sugarcane crop with the use of nitrogen-fixing bacteria has been one of the alternatives to decrease fertilizer consumption and increasing plant production. This study aimed to assess the morphophysiological attributes in the initial growth and nutrition of two sugarcane varieties inoculated with strains of diazotrophic bacteria, individually and in an association, in a greenhouse. The experimental design was a randomized block design in a 2 × 8 factorial arrangement with two cultivars (Co 1341-76 and RB 867515) and eight treatments consisting of bacteria inoculated individually with BR 11140T (Azospirillum amazonense), BR 11175T (Herbaspirillum seropedicae), BR 11192T (Herbaspirillum rubrisubalbicans), BR 11281T (Gluconacetobacter diazotrophicus), and BR 11366T (Burkholderia tropica), inoculation associated with the studied bacteria, N fertilization with 120 kg ha-1 of N, and absolute control without inoculation and nitrogen fertilization. Plants were conducted for 75 days after germination, and biometric variables and nutrient accumulation were measured. The sprouting rate index and root fresh matter were significant for inoculation (p