EVALUATING THE RESPONSE OF MAIZE (Zea mays L.) HYBRIDS TO DIFFERENT LEVELS OF NITROGEN UNDER AGRO CLIMATIC CONDITIONS OF ISLAMABAD

A field study was carried out at NARC Islamabad using a split plot design with three replications in 2017 and 2018. We hypothesized that increasing supplemental levels of N would increase yield and yield components. Hence objective was to evaluate two maize hybrids (H) and nitrogen (N) rates on growth, yield, and yield parameters of maize. Four levels of N kg ha-1 [100 (N1), 175 (N2), N3 (250), N4 (325), and N5 (400) and three maize H [H1 (P-3939), H2 (30-T-60), and H3 (30-Y-87)] in a split plot design with three replications. Data were analyzed using the mixed procedures of SAS. Statistical models included the individual effects of N levels and H, the interactions between N and H and random effect of the year. Yield and yield parameters were improved at 325 kg N ha-1 with significant effects on growth, yield and yield components. The results revealed that growth, yield and yield components were maximized at (P < 0.000) for NARC Islamabad at the N4 level without having an interaction with the H of maize crop. It was concluded that the selection of best H at 325 kg N ha-1 can be used to enhance the efficiency of maize yield in autumn season.