Phosphorus fertilization improves growth analysis traits and reduces anthesis-to-silking interval leading to increased grain yield in maize

A field experiment was conducted on maize hybrids (Bio-9681 and Pro-311) to illustrate the effect of phosphorus (P) on physiological growth analysis traits, anthesis-to-silking interval (ASI) and its correlation with yield. Hybrids were sown with two soil phosphorus (P) levels, viz., 60 and 0 kg ha−1, corresponding to soil P content of 41.5 and 7.4 mg P kg−1 soil, and observations were recorded at three growth stages, 10th leaf (V10), 15th leaf (V15) and tassel emergence (R1) stages. Significant increases were observed in crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area index (LAI), leaf area ratio (LAR) and relative leaf extension rate (RLER) in hybrids in response to P application. Total plant P and grain P uptake increased with P application. The P utilization efficiency for biomass (PUEbm) and grain (PUEg) was higher at P60. Significant increase in cob weight, grain yield and harvest index were recorded at P60 as compared to P0. P stress adversely affected ASI resulting in an increase of 2.8 days in both the hybrids, with a concurrent reduction of 40 % in grain yield. Correlation studies showed significant association of plant P uptake with grain yield at all growth stages, while biomass accumulation at R1 determined grain yield. CGR, RGR, NAR, LAI and LAR exhibited positive correlation at R1 with grain yield, while the latter showed dependency on LAI at all stages. Thus, P fertilization is crucial in maize to maintain optimum yield potential. © 2015, Indian Society for Plant Physiology.