EFFECTS OF NITROGEN RATE ON GROWTH AND YIELD OF BAMBARA GROUNDNUT (Vigna subterranea (L.) Verdc.) IN JALINGO, TARABA STATE, NIGERIA

Field experiments was conducted during the 2015 rainy season at Teaching and Research Farm of Department of Crop Science, Taraba State College of Agriculture Jalingo, to investigate the effect of Nitrogen rates on the growth and yield of Bambara groundnut (Vigna subterranean (L.) Verdc) in Jalingo. The experiments was laid out in split-plot design with three replications and three nitrogen rates, 20kgNha-1 , 25kgNha-1 and 30kgNha-1 as main plot treatment while four intra-row spacing, 20cm, 25cm, 30cm and 35cm as the sub plot treatment. The sub plot size was 3m x 2m (6m2 ). The nitrogen rate doses were applied a week after emergence of the seedlings. Data collected were, percentage seedlings emergence, number of leaves per plant, number of branches per plant, plant height, number of nodules per plant, number of effective nodules per plant, number of non-effective nodules per plant, days to 50% flowering, number of pods per plant, number of seeds per plant, 100 seeds weight, grain yield per plot and grain yield per ha-1 . Data collected were subjected to Analysis of Variance (ANOVA), means were separated using Least Significant Difference (LSD). The results showed that nitrogen rate applied had no significant influence on growth and yield characters. However, significant influence was recorded of intra-row spacing on number of leaves per plant and number of branches per plant at 6WAS with a mean value of 48.24 and 16.80 respectively. Intra-row spacing, 25cm gave the highest mean number (3.14) of noneffective nodules per plant at 30 DAS while 25cm gave the highest number of days to 50% flowering. The result of the interaction revealed that there were significant interaction between Nitrogen rates and intra-row spacing on the number of leaves at 3 WAS and 6WAS. It is recommended that nitrogen rate of 20kgNha-1 and intra-row spacing of 35cm be adopted for Bambara groundnut in Jalingo.