Water availability is the most critical factor for plant growth and development. The application of biostimulants from seaweed extracts can improve crop resistance to water deficit and reduce its negative impact on crop yield. An experiment was conducted to evaluate the effect of four biostimulants: Fertimar (2.5 g·l-1), Fertimar SC (5 ml·l-1), EA 1000-13 (5 ml·l-1), and Fertikelp (5 ml·l-1), formulated from seaweed, on the growth, yield, and oxidative stress of pepper plants subjected to two irrigation regimes: 1) continuous irrigation, 2) irrigation every three days (water stress). To measure the effect of oxidative stress, the activities of the enzymes nitrate reductase (NR), catalase (CAT), superoxide dismutase (SOD), and guaiacol peroxidase (GPX) were evaluated. the proline and the relative content of chlorophyll in leaves were determined. The growth variables evaluated (dry wei...