Can the Integrated Use of Organic Manures and Biofertilizers at Reduced Chemical Fertilization Improve Postharvest Quality and Bioactive Compounds of Papaya Under Punjab Conditions?

Excessive use of chemical fertilizers deteriorates soil health and fruit quality, whereas organic manures or biofertilizers alone often fail to meet the high nutrient requirements of crops like papaya. This study evaluated the combined use of organic manures and biofertilizers with reduced chemical fertilization on postharvest quality and bioactive compounds of papaya cv. “Red Lady.” The experiment consisted of 13 treatments, including 50% of the recommended dose of fertilizers (RDF), farmyard manure (FYM), vermicompost, neem cake, Azospirillum , and phosphate‐solubilizing bacteria (PSB) in different combinations (T 1 –T 12 ) and 100% RDF as the control (T 0 ). Results indicated that the combined application of 50% RDF + FYM (20 kg) + Azospirillum (100 g) + PSB (100 g) significantly ( p ≤ 0.05) increased total phenolic content, total flavonoid content, total carotenoids, β‐carotene, lycopene, total soluble solids, and fruit firmness by 162.22%, 209.49%, 96.15%, 108.33%, 135.04%, 22.27%, and 27.86%, respectively, while reducing physiological loss in weight and titratable acidity by 22.82% and 61.67%, respectively, compared to 100% RDF. Therefore, the integration of 50% RDF + FYM (20 kg) + Azospirillum (100 g) + PSB (100 g) proved the most effective combination for improving papaya fruit quality while reducing chemical fertilizer input by 50% under subtropical conditions.