Effectiveness of Algae as a Low-Cost Alternative Input to Stimulate Sesamum Indicum L. Growth and Productivity for Sustainable Purposes

This study aimed to investigate how microalgae Spirulina (Arthrospira) platensis and macroalgae (Padina pavonica) were used as sources of bio-stimulants instead of chemical fertilizers. The principal goal is increasing various crop plant quality and productivity, particularly in sesame, while reducing environmental impacts. Both types of algal biomass were applied to Sesamum indicum L. plants either as a powder (3 g kg− 1 of soil) or water extract (9 g of algae 720 mL− 1 of tap water) during two developmental stages (the vegetative and productive stages). In the vegetative experiment, the application of S. platensis, either powder or extract, had stimulative effects on all growth parameters and some metabolites in shoots and roots of sesame plants, while the application of Padina and Spirulina as a powder or extract induced the antioxidant concentrations. Tracking their effects until the productivity stage showed that the application of all treatments (powder or extract) to the soil improved the productive criteria, such as branch length, capsule numbers, and seed index. Also, similar responses were observed for the mineral composition of different plant parts. The biomass of algae can be used as a biofertilizer in addition to being a source of nutrition to increase crop production to solve the problems of famine in poor countries. FT-IR analysis was used to qualitatively predict the most important chemical components of P. pavonica and S. platensis as a powder and aqueous extract, which exhibited several active groups that make them effective as bio-stimulants for the sesame plant.