Comparative Efficacy of Liquid and Carrier-Based Biofertilizers on Foliar Nutrient uptake in Guava under Varied Fertilizer Regimes

Abstract

Aim: This study aimed to evaluate the comparative efficacy of liquid versus carrier-based biofertilizer formulations on enhancing foliar nitrogen, phosphorus, and potassium uptake in guava (Psidium guajava L.) cv. Taiwan White, under varying levels of chemical fertilizer application. Study Design: The experiment was conducted using a Factorial Randomized Block Design (FRBD) with three replications. Place and Duration of Study: The investigation was carried out over two consecutive years (2019- 21) at the College of Horticulture, Venkataramannagudem, Andhra Pradesh, India. Methodology: The treatment structure combined three levels of the recommended dose of fertilizers (RDF)—100% (400:160:400 g N:P₂O₅:K₂O/tree), 80%, and 60%—with three biofertilizer applications: carrier-based (NFB+PSB+KSB @ 100 g/tree), liquid (NFB+PSB+KSB @ 5 ml/tree), and a control (no biofertilizers). Standardized protocols were used for leaf sampling and analysis: the Micro-Kjeldhal method for nitrogen, the vanadomolybdo-phosphoric yellow color method for phosphorus, and flame photometry for potassium. Pooled data from both years were subjected to factorial analysis of variance. Results: The combined application of 100% RDF with liquid biofertilizers resulted in the highest foliar nutrient concentrations: 2.06% nitrogen, 0.39% phosphorus, and 1.62% potassium. Liquid biofertilizers consistently outperformed carrier-based formulations across all nutrient parameters and RDF levels. A significant finding was that the 80% RDF treatment amended with liquid biofertilizers achieved a phosphorus level (0.33%) that was statistically equivalent to the highest-yielding treatment (100% RDF + liquid), suggesting a potential 20% reduction in chemical fertilizer use without detriment to foliar phosphorus status. Conclusion: Liquid biofertilizers are demonstrably superior to carrier-based forms for enhancing foliar nutrient content in guava. Their integration, even with a reduced (80%) RDF, can maintain optimal phosphorus nutrition, offering a practical and sustainable strategy for precision nutrient management and fertilizer input optimization in commercial guava cultivation.