Asian Journal of Soil Science and Plant Nutrition

Papaya (Carica papaya L.) is a fast-growing, nutrient-demanding fruit crop with continuous vegetative and reproductive development. The present study evaluated the effects of organic manures and bio-inoculants, applied with different levels of inorganic fertilisers, on the growth, flowering, yield attributes, and fruit yield of papaya cv. CO 7 under the humid tropical conditions of Kerala. The field experiment was conducted in a randomised block design comprising 12 treatments, three replications, and four plants per treatment. Treatments included combinations of the recommended dose of fertilisers (RDF; 240:240:480 g NPK plant⁻¹ year⁻¹), farmyard manure, vermicompost, poultry manure, biovermi, bone meal, wood ash, Trichoderma viride, and Pseudomonas fluorescens. Biometric, floral, and fruit characteristics were recorded, and the data were analysed using MSTAT.C, with treatment means compared by DMRT. The treatment comprising RDF + vermicompost (13 kg plant⁻¹) + T. viride (5 g plant⁻¹) + P. fluorescens (10 g plant⁻¹) recorded the greatest plant height, collar girth, fruit length, fruit girth, fruit weight, fruit volume, seed number, and fruit yield. This treatment produced 42.59 kg fruit plant⁻¹. RDF + poultry manure (10 kg plant⁻¹) + the two bio-inoculants recorded the highest number of fruits per plant and a yield of 40.93 kg plant⁻¹. Fully organic treatments yielded less than the integrated nutrient treatments. Under the conditions of this study, combining RDF with vermicompost and bio-inoculants was the most effective nutrient-management treatment for papaya cv. CO 7.