Effects of Seaweed-Derived Biostimulants on Flowering, Fruit Ripening and Quality Attributes in Tomato

Tomato reproductive development is influenced by both environmental and genetic factors. Climate change modifies these factors, necessitating the development of tools to optimize reproductive processes. This study evaluated seaweed extracts from Macrocystis sp., Les-sonia sp., and Ascophyllum nodosum as biostimulants. The effects of these extracts on flow-ering, fruit set (the transition of flowers into fruit), and fruit ripening were assessed follow-ing foliar application at 0.25% w/v. A significant improvement in floral fertilization (suc-cessful pollination and fruit formation) was observed, with DuoAlgae resulting in a 100% increase compared to the control. Anisotropic growth was also recorded: Fertimar SC in-creased fruit length by 13.77% and the number of mature fruits by 130.41% relative to the control. Regarding fruit quality, chlorophyll content increased at the breaker stage (the ini-tial stage of color change). At the red stage, elevated levels of NO3- (nitrate), K+ (potassium), TSS (total soluble solids), lycopene, and β-carotene were detected. Collectively, these results indicate that biostimulants modulate reproductive development and fruit quality, under-scoring the potential of Peruvian algae to enhance crop productivity