Natural biostimulants as upscale substitutes to synthetic hormones for boosting tomato yield and fruits quality

Natural biostimulants are one of the most promising and eco-sustainable technologies, which can improve the qualitative and productive attributes of horticultural crops. The positive effects of their application derive from their “signaling role” as elicitors of auxin- and gibberellin-like activity, thus constituting a valid alternative to synthetic hormones. Our research aimed to assess the efficacy of a plant extract (Heptamin®) and a bacterial culture filtrate (Capxium®), both rich in natural auxins, and of a synthetic auxin (Auxyger® LG) on the quantitative and qualitative performance, as well as on the economic returns of greenhouse table tomato (Solanum lycopersicum L. cv. Pitagora). The application of plant extract increased the marketable yield (+25.8%), firmness (+25.7%), and fruit lycopene content (+42.5%) compared to the untreated control. In particular, natural biostimulants outperformed synthetic auxin by inducing higher fruit weight (13.1%) and marketable yield (16.2%). On the other hand, no significant differences were recorded as a result of the treatments regarding total soluble solids, pH, and titratable acidity of the fruit juice. Our results suggest that plant biostimulants with auxin-like activity are an excellent tool for boosting tomato production and fruit quality in an eco-sustainable approach. Finally, economic analysis revealed that the application of natural biostimulants resulted in overall higher profitability