Effects of nitrogen levels and harvest interval on the growth and yield of Moringa (Moringa Oleifera Lam) in Sudan Savanna of Nigeria
Field experiment was conducted under irrigation at Bayero University Kano, during 2011/2012 dry season to investigate the effects of different nitrogen levels and harvest interval on growth and leaf yield of Moringa (Moringa oleifera (Lam)). The treatments consisted of four levels of nitrogen (0, 50, 100 and 150kg N ha-1) and three times of harvest interval (2, 3, and 4 weeks). These were arranged in a split plot design with the nitrogen levels allocated to the main plots while the harvest interval allocated to the sub plots and replicated four times. The data collected were subjected to analysis of variance (ANOVA) using the general linear model of GenStat and significant different means were separated using DMRT. The result shows that applications of nitrogen significantly increased plant height, number of leaflets per plant, plant stem diameter, number of branches per plant, fresh and dry weights per plant. Generally, 150kg N ha-1 level gave highest values for all the growth and yield characters assessed. The highest fresh and dry total leaf yields were also obtained with 150kg N ha-1 level. Increase in harvest interval significantly increased fresh and dry leaf yields of Moringa with the highest yields obtained from 4 weeks harvest interval. Nitrogen and harvest interval interaction was found to be significant on fresh and dry leaf yields of Moringa, which indicated that high yields were supported by 150kg N ha-1 at 4 weeks harvest interval.
Keywords: Moringa, harvest interval, Nitrogen level, yield