Nitrogen Uptake at Different Growth Stages of Corn and Its Effect on Important Yield Parameters

บทคัดย่อ

Nitrogen is the primary nutrient governing corn yield. This study compares the contrasting nitrogen dynamics of open-pollinated (OPV) and hybrid corn varieties and their consequential impact on overall yield. However, limited research exists comparatively evaluating the nitrogen uptake and utilization efficiency of these varieties under uniform fertilization rates across distinct growth stages. The study employed a Randomized Complete Block Design (RCBD) with three replications, and all treatment plots received the same fertilizer rate to guarantee unbiased experimental results. All collected data were analyzed using the Statistical Package for the Social Sciences (SPSS) and the Statistical Tool for Agricultural Research (STAR) software. These analyses include One-way Analysis of Variance, Independent Sample T-tests, and Pearson's correlation. The results show that nitrogen uptake in hybrid corn declined gradually and steadily across all growth stages (V8: 3.17%, R1: 2.92%, R3: 2.88%, and R5: 2.27%), contrasting with the fluctuating absorption pattern of the OPV. This superior N management is supported by Nitrogen Utilization Efficiency (NUtE), in which the hybrid (31.55 ± 1.36) achieved a higher NUtE than the OPV (28.09 ± 1.38). The two varieties exhibited a statistically significant difference in N uptake at the R1 stage (p = 0.048), with the hybrid maintaining a higher N concentration (2.92%) than the OPV (2.58%). Interestingly, OPV N uptake at R1 exhibited a strong correlation with kernel weight (0.638), unshelled weight (0.676), ear weight (0.643), and grain yield (0.576), but showed the inverse trend for hybrid corn. These contrasting results confirm that the OPV exhibits lower nitrogen uptake efficiency while the hybrid displays rapid nitrogen absorption, necessitating precision, variety-specific fertilization strategies for yield and environmental stewardship.