Biostimulant prevents yield loss and reduces oxidative damage in tomato plants grown on reduced NPK nutrition*
ABSTRACT Plant biostimulants are substances which have the capacity to modify physiological processes in plants in a way that provides potential benefits to growth, development or stress response. Effects of biostimulant application on two tomato hybrids (Ombeline F1 and Bostina F1) submitted to reduced nitrogen, phosphorus and potassium (NPK) nutrition aiming at prevention of oxidative stress generation as well as yield and fruit quality loss were investigated in this study. According to obtained results, foliar applied Viva® biostimulant decreased superoxide dismutase (SOD, EC 1.15.1.1) and peroxidase (POD, EC 1.11.1.7) activity in tomato leaves even when recommended NPK nutrition was reduced at 40%. Fruit quality parameters (total soluble solids, total acidity, ascorbic acid and lycopene content) and yield were also maintained in reduced macronutrient fertilization when biostimulant was added. Combination of biostimulant with reduced NPK fertilizer enabled stability of cell homeostasis in tomato plants and their better adaptation to stress conditions. The possibility of biostimulant being used as environmental friendly tool in the reduction of mineral fertilizers without negative consequences regarding yield and fruit quality was discussed.