Evaluation of Plant Growth Promoting Bacteria Strains on Growth, Yield and Quality of Industrial Tomato.

Plant growth promoting bacteria (PGPB) are used as biostimulants to improve the growth and yield as well as the quality of crops. In the present study, nine strains of PGPB and one solid mix consisting of two of them were evaluated on the cultivation of industrial tomato under specific soil and climatic conditions. The results showed that treatment increased dry weight of the tomato plants by 39%, and the photosynthetic rate was increased by 9.9%. The application of , , , and increased mean fruit weight per plant 26.78-30.70% compared to that of control. Yield per plant was increased 51.94% with the use of compared to that of control. The quality of the fruits in nearly every bacteria strain was improved. and the mix of and (1:1) increased the most total soluble solids in the tomato fruits (4.70° Brix), and increased content in lycopene and total carotenoids by 52.8% and 25%, respectively; increased Pectin methylesterase (PME) activity (24.94 units/mL), and , along with the mix of and , increased Poligalacturonase (PG) activity the most (30.09 and 32.53 units/mL, respectively). Most of the bacteria strains presented an increased antioxidant activity significantly better that that of the control up to 31.25%. The results of this study confirmed that the use of PGPB as biostimulants can improve the yield and the quality of industrial tomato.