Timothy E, and Futuless KN
Response of roselle (Hibiscus Sabdariffa L.) to sowing date and nitrogen fertilizer levels were examined in experiments conducted during the 2011 and 2012 cropping seasons at the Research and Teaching farm of the Department of Crop Science, Adamawa State University, Mubi. The experiment which consisted of four fertilizer levels viz: OkgN/ha, 50kgN/ha, 100kgN/ha and 150kgN/ha as sub plots and three sowing dates viz: SD1, (21/7/2011/2012), SD2(31/7/2011/2012), and SD3(10/8/2011/2012) as main plot laid in a split plot design and replicated three times. Data were collected on plant height (cm), number of branches per plant, Days to 50% flowering fresh weight of calyx, dry weight of calyx and 1000 dry seed weight. Result revealed that SD1 and 150kgw/ha had significantly superior plant height, number of branches per plant, fresh and dry weight of calyx and 1000 dry seed weight. Days to 50% flowering significantly recorded lower number of days at SD1, compared to other treatments in 2011 and 2012. Result from this also show that, there were significant interaction between sowing dates and nitrogen fertilizer level among some of the treatments. These result indicate that SD1, and 150kgN/ha performed better and thus had impact on the growth, development and yield of roselle.