Boosting cherry tomato yield, quality, and mineral profile through the application of a plant-derived biostimulant

The present experiment addressed the effects of a plant-derived biostimulant (PDB, Bioup (R) TF) on fruit quality and composition of two greenhouse cherry tomato cultivars (Caravaggio and Creativo) grown during the autumn-winter. The biostimulant application enhanced the marketable fruit yield up to 1.148 g m(-2) of 'Creativo' (+16 %) and increased the fruit dry matter, firmness, and chroma (C*), particularly of 'Caravaggio' (by 23, 12, and 11 %, respectively). 'Caravaggio' also showed the strongest increase in total polyphenols (+26 %) and carotenoid contents (+50 %) in response to the treatment. This trend paralleled the strongest rise of the in vitro antioxidant activity of its fruit extracts, as revealed by the DPPH and FRAP assays. Moreover, the biostimulant treatment resulted in higher concentrations of 10 among 12 minerals analyzed in fresh fruit. This effect was particularly relevant for calcium, manganese, and copper, whereas 'Caravaggio' proved the strongest rise for potassium, magnesium, sodium, and zinc. Interestingly, the biostimulant application did not promote or even reduced the concentration of nickel in fresh 'Caravaggio' and 'Creativo' (-38 %) fruit, respectively. This suggests that the integration of PDBs in the framework of agronomic strategies could assist in producing Ni-poor tomatoes while increasing, at the same time, their levels in health-promoting minerals.