Irrigation Scheduling for Onion (Allium cepa L.) at Various Plant Densities in a Semi-Arid Environment
A.O.A. Dorcas 1, M.D. Magaji1, A. Singh2, R. Ibrahim1 and Y. Siddiqui3 Department of Crop Science, UsmanuDanfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Sokoto State, Nigeria. 2 A. Singh, School of Biosciences, Faculty of Science, The University of Nottingham, Malaysia Campus, JalanBroga, Semenyih 43500, Selangor, Malaysia; 3Faculty of Agriculture, University Putra Malaysia, 43400 UPM SERDANG, Selangor, Malaysia.
Corresponding author’s e-mail Ajit.Singh@nottingham.edu.my, ajitsingh66@yahoo.com Abstract Irrigation scheduling is necessary for increased onion production in a semi-Arid tropic where water is scarce and a limiting factor for crop production.Field experiments were conducted during the dry season of 2004/2006 and 2005/2006 at the Fadama Teaching and Research Farm, UsmanuDanfodiyo University, Sokoto, Nigeria. The objective was to investigate the response of onion to irrigation scheduling and population density. The treatments consisted of factorial combination of four irrigation intervals (3, 6, 9 and 12 days) and five population densities (100000, 160000, 200 000, 250 000 and 500000 plants ha-1 corresponding to 30 x 30, 25 x 25, 20 x 25 and 20 x 20 and 20 x 10 cm spacing, respectively laid out in split plot design replicated three times with irrigation interval allocated to the main plots and plant density on the sub plots. Result revealed that plant height, leaf count, mean bulb diameter, mean cured bulb weight and onion yield in both trials and the combined analysis were significantly favoured by 3 and 6 days interval. However, lower plant densities (100,000 and 160,000 plantha -1) where found to increase leaf count, mean bulb diameter and mean cured bulb weight. But total onion yield was significantly