Optimizing corn productivity: Hybrid and intra-row spacing effects on growth, yield, and nutritional quality

Abstract

Abstract Ongoing genetic enhancements in corn hybrids for high plant density tolerance compel agronomists to periodically reassess optimal intra-row spacing. Accordingly, this investigation assessed the growth, yield, and chemical properties of three commercial hybrids (namely Pioneer 3444, Hytech 2031, and Giza 168) sown at varied intra-row spacings (15–35 cm). Results revealed that Pioneer 3444 (V1) had observably higher chlorophyll content and leaf area index than Hytech 2031 (V2) and Giza 168 (V3), whereas significant decreases in duration to 50% tasseling and silking were documented (p < 0.05). Reference to V1 and V3, the V2 hybrid exhibited higher nitrogen and protein content (2.01 and 11.53%, respectively). Notably, the optimum intra-row spacing was noticed at 25 cm, showing significant improvements (p < 0.05) in shelling percentage (82.72%), weight of 100-grain (41.39 g), grain yield (7549.78 kg/ha), and carbohydrate (83.40%), nitrogen (2.15%), and protein content (12.24%) relative to other spacings. Moreover, the V3 hybrid grown at 35 cm spacing extended the time to 50% tasseling (70.67 days) and increased number of grains per row (46.67). Among all hybrid-spacing interactions, the V1 sown at 25 cm produced the highest (p < 0.05) ear diameter (5.73 cm), 100-grain weight (44.50 g), and grain yield (8206.87 kg/ha). Most importantly, the synergistic effect of V2 × 25 cm spacing resulted in the greatest nitrogen (2.27%) and protein (12.93%) contents, closely followed by those of V1 under the same 25 cm spacing (2.25 and 12.80%, respectively), whereas V1 × 25 cm spacing significantly maximized carbohydrate content (85.00%). Correlation analysis illustrated that the reduction in duration to 50% tasseling and silking accounted for 65–90% of the increase in ear diameter, 100-grain weight, and grain yield. These findings demonstrate that farmers should cultivate the V1 hybrid at a 25 cm spacing to achieve an optimal balance between grain yield and quality, thereby maximizing corn productivity and potential profitability.