Optimization of nitrogen to maize hybrids in northern transition zone of Karnataka, India

Abstract

A field experiment was conducted during rainy seasons of 2015 and 2016 in northern transition zone (NTZ) ofKarnataka, India under rainfed condition to optimize nitrogen (N) fertilizer to selected maize hybrids. The treatments werelaid out in a split plot design wherein three rates of N (N1= 50, N2=100 and N3= 150 kg N ha-1) applied to four maize hybrids(H1= Nithyashree, H2= NK-6240, H3=GH-0727 and H4= 900-M-Gold) with N as main plots and hybrids as sub-plots.Thepooled analysis of results indicated that the most of the crop growth and yield attributes viz., plant height, LAI, total aboveground biomass, number of rows per cob and grains per cob were highest with the application of 150 kg N ha-1, but werefound on par with those at 100 kg N ha-1. The highest yield however was recorded at 150 kg N ha-1 (87.4 q ha-1) but wasclosely followed by that at 100 kg N ha-1 (87.1 q ha-1). Among the four hybrids tested NK-6240 and 900-M-Gold hybridsin that order were found to be the highest yielders in NTZ under rainfed conditions with 91.7 and 89.0 q ha-1 of grain yield,respectively. The interaction among three N levels and four hybrids showed that hybrid NK-6240 at 150 kg N ha-1 gave thehighest yield (92.1 q ha-1), but was found on par with that at 100 kg N ha-1 (91.9 q ha-1). This study showed that 100 kg Nha-1 is the economically optimum level and among the hybrids NK-6240 and 900-M-Gold in that order are the bestperformers for NTZ on black soils