Seaweed Extracts and Composts (Macrocystis spp.) as biostimulants for tomato seedlings (Solanum lycopersicum L.)

Resumen

Objective: To evaluate different application rates of seaweed extracts and compost derived from Macrocystis spp. as biostimulants in tomato plants (Solanum lycopersicum L.) grown under greenhouse conditions. Design/methodology/approach: A completely randomized design with four replications was employed. The following treatments were evaluated: (1) a Macrocystis spp. seaweed extract obtained in the laboratory under controlled temperature and pressure conditions; (2) a Bokashi-type compost based on the same seaweed; and (3) two commercial seaweed extracts, ProalG® and NPKelp®. Synthetic fertilization and water were used as controls. All treatments were applied at three different rates. Results: The treatments that produced the greatest foliar biomass, plant height, and stem diameter were NPKelp® at the medium rate, ProalG® at the high rate, and the laboratory-obtained Macrocystis spp. seaweed extract at the high rate. Regarding nutrient concentration in plant tissue, the treatments NPKelp® (medium rate), ProalG® (high rate), seaweed extract (high rate), and compost promoted the highest macronutrient concentrations. Findings/conclusions: The use of seaweed extracts and compost as biostimulants constitutes a viable alternative for reducing the use of chemical fertilization in tomato production.