Seed priming with Ascophyllum nodosum (L.) Le Jolis extract macroalgae in soybean

Seed priming with biostimulant for soybean is a promising practice contributing positively to the physiological quality and vigor of seedlings, but there are little studies regarding protocols of bioinputs, such as Ascophyllum nodosum L. seaweed extract. We aimed to evaluate the effect of doses of A. nodosum macroalgae in seed priming and its impact on germination and seedling vigor of soybean. Seeds were subjected to priming with A. nodosum extract (ANE) at doses of 0, 1, 2, 3, 4, and 5 mL kg seed-1 during 15 min. Priming with ANE did not influence the first count and seed germination. Soybean seedlings from priming with 5 mL kg-1 ANE showed higher growth and shoot and root dry biomass. We observed increase 18% for shoot dry matter with priming of 5 mL kg-1 ANE compared to untreated seeds. The responses were variable for the emergence speed index in function ANE and did not influence the photochemical processes in photosystem II. Seed priming with ANE contributed in higher chlorophyll index. ANE showed a biostimulant effect on soybean seedlings, providing better growth and biomass characteristics, being promising in seed priming, but further studies are suggested in order to increase information regarding its use protocol for soybean.