Sustainable Valorization of Grape Pomace Using Biostimulant Oligosaccharins to Improve Germination and Early Physiological Responses of Solanum betaceum

Grape pomace‐derived oligosaccharins represent a promising strategy for producing natural plant biostimulants from agro‐industrial by‐products. This study evaluated the effects of grape pomace‐derived oligosaccharins germination and early physiological responses of tree tomato ( Solanum betaceum ), a species characterized by slow and irregular germination. Seeds were imbibed for 12 h in solutions containing 0, 5, 10, and 20 mg L −1 of oligosaccharins and grown under controlled conditions. Germination percentage, emergence, root and shoot growth, and biochemical traits including chlorophylls, carotenoids, total phenolics, and antioxidant capacity were determined. Results showed a positive effect of oligosaccharins on germination performance and biochemical traits. Oligosaccharin treatments increased germination from 11% (control) to 28%–40% and advanced maximum emergence by 6–10 days depending on the dose. Root and shoot length and growth rate parameters did not show statistically significant differences among treatments. The 10 mg L −1 oligosaccharin treatment resulted in the highest accumulation of photosynthetic pigments, with chlorophyll content increasing by up to 159% relative to the control, with statistically significant differences among treatments ( p < 0.05). Carotenoid content also showed significant increases depending on the oligosaccharin dose, ranging from 47% to 169% compared to the control ( p < 0.05). Total phenolic content increased by 9%–18% in oligosaccharin‐treated seedlings, with significant differences observed among treatments ( p < 0.05). In contrast, antioxidant capacity assessed by the DPPH assay did not show statistically significant differences among treatments ( p > 0.05). These findings indicate that grape pomace oligosaccharins enhance germination and activate early physiological responses in S. betaceum , highlighting their potential use as sustainable biostimulants for seedling production and the valorization of vitivinicultural residues.