Genotype and nitrogen effects on grain yield and yield-related traits of maize (Zea mays L.) hybrids

Abstract

Genotype and nitrogen application are important determinants of grain yield in maize. This experiment was carried out in split-plot design with two factors (maize hybrids as the main factor and nitrogen rates as the sub factor) arranged in randomized complete block design (RCBD) with three replications. The maize hybrids including Rampur Hybrid-2, Rampur Hybrid-4 and Rampur Hybrid-6 were main plots, and four nitrogen rates of 0, 140,160, and 180 kg N ha–1 were sub-plot. Results revealed that hybrids had significant effects on the days to 50% tasselling, cob circumference, number of kernel rows per cob and grain yield. Similarly, nitrogen rates had significant effects on all parameters except on the days to 50% tasselling and silking. The highest values of cob length (18.31 cm), no of kernel rows per cob (13.22), no of kernels per cob (33.36), cob circumference (13.90 cm) was recorded from the plot fertilized with 180 kg N ha–1. Rampur Hybrid-2 produced the highest yield (6.19 t ha–1), whereas the lowest yield was found in Rampur Hybrid-6. Similarly, 180 kg N ha–1 produced a significantly higher yield (7.06 t ha–1) which was followed by 160 kg ha–1 (6.71 t ha–1), 140 kg ha–1 (6.30 t ha–1) and the lowest yield (3.93 t ha–1) with 0 kg N ha–1. Therefore, among the hybrids evaluated, Rampur Hybrid-2 could be an appropriate hybrid variety for the cultivation at Dang district and similar conditions in Nepal. This study suggests that maize production can be maximized by cultivating Rampur Hybrid-2 with the use of 180 kg N ha–1 in the inner Terai region of Nepal.

Keywords

• grain yield
• growth
• hybrids
• maize
• nitrogen