Effect of Azotobacter and Phosphate Solubilizing Bacteria on Growth and Yield Parameters of Tomato

Introduction: Tomato (Solanum lycopersicum L.) is a nutritionally rich vegetable crop of global importance, widely cultivated in tropical and semi-arid regions. In 2022–23, worldwide tomato production reached 20 million metric tonnes from 8.64 million hectares, with Maharashtra contributing 0.67 million metric tonnes from 0.18 million hectares. Problem: Excessive reliance on chemical fertilizers to overcome nutrient deficiencies leads to soil degradation, reduced microbial diversity and environmental concerns. There is a pressing need for eco-friendly alternatives to sustain productivity while maintaining soil health. Aim: This study was undertaken to evaluate the effectiveness of beneficial microorganisms, particularly Azotobacter and phosphorus-solubilizing bacteria (PSB), in improving growth, yield, and soil nutrient status of tomato, with reduced chemical fertilizer input. Methods: A pot-culture experiment was conducted using different treatments of Azotobacter and PSB, alone and in combination, along with varied levels of recommended N and P fertilizers. Growth, yield attributes, and soil nutrient status were recorded and compared. Results: The combined treatment of seedling inoculation with Azotobacter + PSB along with 75% recommended N & P significantly outperformed other treatments. It recorded the highest number of branches (19.27), plant height (73.73 cm), and root length (22.57 cm). Yield parameters also improved, with minimum days to flower initiation (39.40 days), maximum fruits per plant (13.82), polar diameter (6.13 cm), equatorial diameter (4.99 cm), average fruit weight (73.33 g), fruit yield per plant (1.013 kg), and total yield per hectare (375.32 q). Soil nutrient status after harvest also showed higher available N (282.24 kg/ha) and P (36.47 kg/ha). Novelty: The study demonstrates that integration of microbial inoculants with reduced fertilizer doses can enhance tomato growth, yield, and soil fertility while lowering chemical input. This highlights the potential of biofertilizers as sustainable tools for nutrient management and eco-friendly tomato cultivation.