Evaluation of sargassum (Sargassum spp.) extracts as a method of organic fertilization of sugarcane

Objective: To evaluate the effect of the application of commercial sargas-sum extract as a foliar biofertilizer in sugarcane cultivation.Design/methodology/approach: Five fertilization treatments were applied in an experimental plot cultivated with sugarcane: Conventional mineral fer-tilization (T1); Foliar fertilization with 100% sargassum extract (T2); Foliar fertilization with 50% sargassum extract (T3); Conventional 50% mineral fertilization plus foliar fertilization with 50% sargassum extract (T4), and control without fertilization (T5), in a completely randomized experimental design.Results: The highest stem height was observed in the statistically equal T1, T2 and T4 treatments, but higher than that of the control. The larger diam-eter was observed in the T4 treatment, significantly larger than that of the control, in which a statistically lower number of leaves was also observed. The highest field yield was observed in statistically identical T1, T2 and T4 treatments, but superior to that of the control.Limitations on study/implications: Further evaluation of commercial ex-tracts of sargassum applied as foliar fertilizers in crops is considered nec-essary to corroborate the results presented here. A study of the mechanisms of action of the compounds present in sargassum extract on crop physiology, when applied as foliar fertilizers, is also considered necessary.Findings/conclusions: Commercial sargassum extract is a sustainable alternative to sugarcane biofertilization, which does not pose a risk of chemical contamination like that of conventional mineral fertilization.