Effects of Two Fruit-Fattening Biostimulants on Yield and Fruit Quality of Greenhouse-Grown Saladette Tomato (Solanum lycopersicum L.)

This study aimed to evaluate the effect of two fruit-fattening biostimulant formulations on tomato (Solanum lycopersicum L.) growth, fruit quality, and yield under greenhouse conditions. The experiment was conducted in a gable-type greenhouse at the Technological University of Culiacán, Sinaloa, Mexico. Two fruit-fattening biostimulants (A and B) were evaluated together with an untreated control. The evaluated variables included leaf greenness (SPAD index), fruit firmness (PSI), total soluble solids (˚Brix), fresh fruit weight, and yield per hectare. The results showed that biostimulant application significantly affected fruit firmness, total soluble solids, fresh fruit weight, and yield. Biostimulant A produced the highest fresh fruit weight (221.6 g∙fruit⁻¹) and yield (470.8 t∙ha⁻¹), followed by Biostimulant B (180.4 g∙fruit⁻¹ and 367.25 t∙ha⁻¹), whereas the control treatment showed the lowest values (139.6 g∙fruit⁻¹ and 320.8 t∙ha⁻¹). No significant differences were observed among treatments for the SPAD index, whereas total soluble solids were significantly increased by Biostimulant A (5.85 ˚Brix) compared with Biostimulant B (4.75 ˚Brix) and the control (4.30 ˚Brix). Fruits from plants treated with Biostimulant A also exhibited the highest firmness (8.48 PSI). Biostimulant A improved tomato yield and enhanced important fruit quality attributes. These findings indicate that Biostimulant A represents a promising agronomic strategy for improving tomato productivity under protected cultivation.