The biostimulant manufactured using diazotrophic endophytic bacteria and humates is effective to increase sugarcane yield

Background: The use of biostimulants in agriculture has demonstrated great potential but more consistent field results are required for wider farm acceptance. We evaluated different delivering methods for the biostimulant produced with plant growth-promoting bacteria mixed with humic acid-like substances isolated from vermicompost in the commercial sugarcane crop yield during 3 consecutive years. Results: Foliar spray had a better performance than furrow application and the best result was obtained when the biostimulant was applied at 60 days after emergence, thus enhancing 37% of the stem yield when compared to control. In the first and second ratoons, the productivity increases 5 and 24%, respectively. The first ratoon was marked by severe drought stress that hit all the southeastern of Brazil. Moreover, the assay using strip plot design with a large parcel area confirms the promotion of sugarcane yields by biostimulant during two consecutive ratoons increasing 19 and 18% that represent 11 and 13 tons ha(-1) more than the control. The use of biostimulant did not change soluble solid content and polarizable sugars in the sugarcane juice obtained from both experiments. Conclusions: The biostimulant formulated with endophytic diazotrophic bacteria and humic acids represents a low-cost technology that increases the sugarcane yield with economic use of fertilizers to enhance crop yield.