Improving tomato production while preserving fruit quality with Carpobrotus edulis extract as a biostimulant: A valorization approach for an invasive plant species

Valorizing invasive plant biomass in the agricultural sector offers a sustainable strategy for environmental mitigation and resource recovery within a circular-economy framework. Carpobrotus edulis, an invasive species currently managed through manual removal in Mediterranean-type ecosystems, represents an underutilized source of bioactive compounds for the development of plant-based biostimulants. This study evaluated the efficacy of an aqueous acetone extract of C. edulis leaves, obtained from invasive biomass cleared from an invaded natural area, to enhance yield and fruit quality in tomato (cv. Moneymaker). Greenhouse-grown plants were sprayed with either the extract or a control application at the fruit set stage, followed by a reinforcement dose one week later. We evaluated fruit production, ripening, and fruit organoleptic traits at harvest. Moreover, the impact of preharvest application on postharvest tomato ripening rate and its quality was also assessed. Results showed that biostimulant application of C. edulis extract, a natural source of salicylic acid and melatonin, increased the number of fruits per plant and significantly accelerated on-vine ripening without compromising fruit quality at harvest or after postharvest ripening. Furthermore, the advantages, limitations, and mitigation strategies for the real-world application of this extract as a biostimulant are discussed. These findings highlight the potential of C. edulis biomass as a valuable resource for developing biostimulants, transforming an environmental management waste into a high-value agricultural input.