AMFAND PGPR SYNERGY: BOOSTING TOMATO YIELD AND QUALITY IN VERTISOL WITH LESS FERTILIZER

Abstract

Increasing demand for high crop productivity with reduced dependence on mineral fertilizers has stimulated interest in microbial inoculants capable of improving nutrient acquisition and crop quality. A two-year field experiment was conducted during the Rabi seasons of 2023–24 and 2024–25 at the Research Farm of the Vegetable Research Centre, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India, to evaluate the effects of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on tomato productivity and fruit quality under Vertisol conditions. Twelve nutrient and microbial inoculation treatments were evaluated in a randomized block design with three replications. Pooled analysis revealed significant improvements in tomato productivity, plant nutrient concentration and fruit biochemical quality following combined microbial inoculation. Soil application of 75% RDF + AMF + PGPR (Pseudomonas fluorescens, Bacillus megaterium and Trichoderma asperellum) recorded the highest plant N (1.97%), P (0.30%) and K (1.99%) concentrations. The treatment also produced the highest fruit yield (376.74 q ha⁻¹), representing increases of 117.54% and 27.27% over the absolute control and 100% RDF, respectively. The same treatment produced the highest dry matter yield (46.34 q ha⁻¹), with increases of 66.03% and 38.49% over the absolute control and 100% RDF, respectively. Fruit quality was substantially improved, with 2.49% reducing sugar, 5.26% non-reducing sugar, 5.85 °Brix TSS, 9.12 mg 100 g⁻¹ lycopene and 26.42 mg 100 g⁻¹ ascorbic acid. Combined microbial inoculation through soil application consistently outperformed the corresponding seedling application. Among individual microbial inoculation treatments, soil application of AMF with 75% RDF performed best. The results demonstrate that AMF–PGPR integration with 75% RDF can simultaneously enhance tomato yield, plant nutrient concentration and fruit quality while reducing mineral fertilizer input by 25% under Vertisol conditions.