EFFECT OF TIME OF NITROGEN APPLICATION ON THE PERFORMANCE OF MAIZE (Zea mays L.) VARITIIES AT MUBI, NORTHERN GUINEA SAVANNA OF NIGERIA

ABSTRACT A field study was conducted in 2011 and 2012 rainy seasons at Mubi, in the northern Guinea Savanna ecology of Nigeria. The trial was conducted in a split-plot design with two maize (OBA -98 and OBA -SUPER) varieties in the main plots. In the sub-plots, nine timings of nitrogen application and zero fertilization as a control were assessed. Throughout the study, the two varieties exhibited similar performance in all the parameters evaluated.. Application of basal dose (60:60: 60kgN,P 2 0 5 ,K 2 0 ha -1 ) two weeks after sowing (WAS) plus 60kgN ha -1 4WAS tasseled earlier than zero fertilizer application and basal +30kgNha -1 6WAS+30kgNha -1 10WAS. Combined grain yield for two years showed that the highest grain yield was obtained from the application of basal dose +30kgNha -1 4WAS+30kgNha -1 8WAS. The treatment out-yielded zero fertilizer rate and basal dose+30kgNha -1 WAS+30kgNha -1 8WAS. In the combined analysis, all N fertilized treatments exhibited similar cob length, cob diameter, 100 grain weight and plant height at 9WAS, but were all significantly higher than zero fertilizer treatment