Response of maize (Zea mays L.) hybrids to different levels of nitrogen

Nitrogen is one of the key factors for higher grain production of hybrid maize (Zea mays L.). The use of improved varieties and optimal use of nitrogen (N) fertilizer is important for exploiting yield potential of maize. This work was carried out to evaluate the effects of N rates on grain yield and yield attributing traits of hybrid maize. Two hybrids (RML-86/RML-96 and RML-95/RML-96) and five levels of nitrogen (120, 150, 180, 210 and 240 kg N/ha) were evaluated at research field of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal in spring season of  2017 and 2018. The experiments were conducted in two factorial randomized complete block design (RCBD) with three replications under rainfed condition. The pooled analysis (2017 and 2018) showed that the highest grain yield 10.5 and 10.5 t/ha were given by hybrids RML86/RML96 and RML95/RML96, respectively with the use of 150 kg N/ha in 2017. The hybrids RML-86/RML-96 and RML-95/RML-96 produced the highest grain yield 7.49 and 7.68 t/ha, respectively with the use of 150 kg N/ha in 2018. The mean grain yield (2017 and 2018) showed that both maize hybrids produced the highest grain yield 10.5 t/ha in 2017 and 7.58 t/ha year in 2018 with the application of 150 kg N/ha. The application of nitrogen fertilizer on grain yield was found significant (P<0.05) in both years. Therefore, the application of 150 kg N/ha has significantly increased grain yield of maize, Therefore, this dose of nitrogen can be recommended for higher maize production in Chitwan, Nepal in spring season under rainfed condition