Effect of Azospirillum and Azotobacter Species on the Performance of Cherry Tomato under Different Salinity Levels

Abstract

Abiotic stress has a negative impact on plant physiology, influencing the overall growth and development of plant crops. Saline stress is one of the most serious environmental issues limiting crop plant production. Biofertilizers are reparative elements used in soil to increase tolerance to salinity and drought stress. We investigated the effect of salinity stress on qualitative and quantitative characteristics of cherry tomato plants (Lycopersicon esculentum cerasiforme) with biofertilizer application 0, 15 and 30 days after transplanting in this study. After different days of transplantation, different levels of salinity (0, 50, 100, and 150 mM) were used with biofertilizer (Azospirillum sp. and Azotobacter sp.) application (0, 15 and 30 days). The salinity (150 mM NaCl) significantly affected the studied variables, which were recorded with minimum levels of leaf area (52.42 cm(2)), root length (6.54 cm), fresh root weight (13.64 g), yield (6.52 tons/ha), leaf chlorophyll content (36.11 mg/m(2)) and maximum levels of total soluble solids (TSS, 8.87 degrees Brix). Control samples had higher leaf area (58.35 cm(2)), root length (15.23 cm), fresh root weight (17.86 g), yield (9.39 tons/ha), leaf chlorophyll content (44.09 mg/m(2)), and lower TSS (7.93 degrees Brix). Plants that received biofertilizer (15 days after transplanting) had higher plant height (73.41 cm), stem diameter (0.74 cm), leaf area (61.16 cm(2)), root length (15.35 cm), fresh root weight (18.38 g), root dry matter (60.41%), yield (10.43 t/ha), leaf chlorophyll content (42.55 mg/m(2)), fruit dry matter content (10.12 g), pH 4.52, and TSS (9.30 degrees Brix). The minimum plant height (51.33 cm), stem diameter (0.55 cm), leaf area (49.60 cm(2)), root length (7.04 cm), fresh root weight (12.76 g), root dry matter (42.16 g), yield (5.15 tons/ha), leaf chlorophyll content (35.18 mg/m(2)), fruit dry matter content (6.59 g), pH 4.27 and TSS (7.55 degrees Brix) were recorded in plants with no application of biofertilizer. The present study revealed that most growth and quality variables were negatively affected by salinity except for TSS, which showed positive effect with application of 150 mM of NaCl. Biofertilizer application at 15 days significantly influences the quantitative and qualitative attributes of cherry tomato under different levels of salinity.