Effect of Parts of the Plant on the Crude Protein and Mineral Composition on Some Varieties of Maize (Zea Mays) in Ekpoma, Edo State

Abstract This study investigates the effect of different maize plant parts (leaves, stem, and their combination) on the crude protein and mineral composition of three maize varieties (Local, SUWAN-1-SR, and SUMMAZ-52) at two growth stages (Week 4 and Week 8) in Ekpoma, Edo State. Crude protein (N) and key minerals (P, K, Mg, Ca, Na, Fe, Zn, Mn) were analyzed for variations across plant parts and varieties. The combination of leaves and stems showed the highest nutrient concentrations, with nitrogen (N) values ranging from 1.97% to 2.43% at Week 4 and 1.97% to 2.10% at Week 8. Potassium (K) was highest in SUWAN-1-SR at Week 4 (7.85%) and lowest in SUMMAZ-52 at Week 8 (4.27%). Iron (Fe) content varied significantly, with the highest in SUWAN-1-SR at Week 4 (47.22 mg/kg) and lowest in SUMMAZ-52 at Week 8 (26.89 mg/kg). Significant differences were found between Weeks 4 and 8 for nitrogen, phosphorus, potassium, and iron (p < 0.05). The findings suggest that maize leaves and stems contain essential nutrients that vary with growth stage. It is recommended that maize forage be harvested at earlier growth stages (Week 4) to optimize crude protein and mineral content for livestock feed. Further research on these findings for animal nutrition and soil fertility is recommended.