Field experiments were conducted during 1998 and 1999 rainy seasons at the Dry Land Teaching and Research Farm of Usmanu Danfodiyo University, Sokoto, to study the response of roselle to farmyard manure, nitrogen and their interaction on the growth and yield of roselle. Treatment consisted of factorial combination of four rates of farmyard manure (0, 2.5, 5.0 and 7.5 t/ha) and four levels of nitrogen fertiliser (0, 25, 50 and 75 kg N/ha) laid out in a randomized complete block design replicated three times. The result showed that there was significant response to applied manure and N-fertiliser on number of leaves up to 5 t/ha manure and 50 kg N/ha. There was no significant increase in calyx yield by raising manure rate from 2.5-7.5 /ha or nitrogen rate from 50 to 75 kg N/ha. Thus, 2.5 t/ha manure and 50 kg N/ha were considered adequate for calyx production in roselle in Sokoto Semi-arid Tropics. However, for maximum number of vegetable leaves additional manure (5-7.5 t/ha) and N fertilizer (50-75 kg N/ha) may be necessary.
Key words: Roselle, Hibiscus sabdariffa, Farmyard manure, Nitrogen fertilizer, Semi-arid.