MAIN AND RESIDUAL EFFECTS OF FERTILIZER SOURCES ON MINERAL COMPOSITION OF PASSION FRUIT (Passiflora edulis Sims) IN THE DERIVED SAVANNAH ECOLOGY OF NIGERIA

Field experiment was carried out at Prince Abubakar Audu University Teaching and Research Demonstration Farm, Anyigba, using a 2 X 10 factorial laid out in a randomized complete block design (RCBD) with four replicates to investigate the effect of fertilizer sources on mineral composition of Passiflora edulis Sims. The study focused on evaluating the effects of organic, inorganic and combined fertilizer applications on the levels of sodium, phosphorus, calcium, potassium and magnesium in hybrid and yellow passion fruit varieties over two growing seasons (2022 and 2023). Results showed both varieties of passion fruit and the type of fertilizer used had a significant effect on the fruit's mineral composition. Hybrid variety consistently had higher levels of phosphorus (2279 mg kg-1) and potassium (1446.2 mg kg-1), while the yellow passion fruit variety had greater amounts of calcium (4375.2 mg kg-1) and magnesium (1768.3 mg kg-1). Application of Poultry manure at 20 t ha-1 gave the highest mineral concentrations in sodium (590.06 mg kg-1), phosphorus (2570.6 mg kg-1), calcium (4942.9 mg kg-1), potassium (1533.5 mg kg-1) and magnesium (1933.3 mg kg-1). Combination of poultry manure (5 t ha-1), pig slurry (5 t ha-1), NPK 20:10:10 (100 kg ha-1) and NPK 15:15:15 (100 kg ha-1) also resulted in high calcium (4787.3 mg kg-1), potassium (1549.7 mg kg-1) and magnesium (1960.9 mg kg-1) levels. Combining poultry manure (10 t ha-1) with NPK 15:15:15 (200 kg ha-1) produced the highest sodium (570.24 mg kg-1) and phosphorus (2244.7 mg kg-1) contents. There were also notable interactions between the variety of passion fruit and the type of fertilizer used, indicating that different genotypes responded differently to the various fertilizer treatments. This study highlights the value of integrated nutrient management, particularly the use of organic fertilizers like poultry manure, in improving soil fertility and enhancing the mineral content of passion fruits.