EFFECT OF INTRA–SPACING AND NITROGEN RATES ON GROWTH AND YIELD OF SORGHUM (Sorghum bicolor L.) Var. ICSV 400 S.Miko and A. A. Manga Department of Agronomy, Faculty of Agriculture, Bayero University, PMB 3011, Kano Abstract Two field trials were conducted in 1999 and 2001 rainy seasons in the Teaching and Research Farm of the Institute for Agricultural Research, Ahamadu Bello University, Zaria( 11 0 11’ N and 7 0 38’ E) to test the effect intra- row spacing and nitrogen rates on growth and yield of Sorghum (Sorghum bicolor L.) var. ICSV 400. The treatments were made up of three intra-row spacing (25, 50 and 75 cm) combined with four nitrogen rates (0, 30, 60 and 90 kg N/ha). Randomized complete block design was used for the trials. The results have shown that intra-row spacing had a significant influence on plant height, number of leaves per plant, dry matter, and grain yield but had no effect on stand count. Neither intra-row spacing nor nitrogen had an effect on flag leaf area or panicle length. Nitrogen application was also observed to have significant influence on all the characters mentioned earlier. The closest intra-row spacing of 25 cm gave 35.06 and 38.59% increase in yield in 1999 and 2001 respectively over the widest spacing of 75 cm. The response of sorghum yield to nitrogen was up to 60 and 90kg N/ha in 1999 and 2001 respectively. The increase in yield when these responses were compared to plots that did not receive nitrogen was 32.44 and 27.0% for 1999 and 2001, respectively. Keywords: Nitrogen, Intra-row spacing, Sorghum bicolor L. var. ICVS 400 Introduction Sorghum (Sorghum bicolor L.) commonly referred to as Guinea corn in West Africa is the fourth most important cereal in the world after rice wheat and maize (Dogget, 1970). It is used in peasant and subsistent farming communities in making beer and malt and its stem is used in fencing and construction of temporary buildings. In more advanced agriculture the grain is used as a livestock feed while the whole crop is used as silage or forage (Cobley, 1976). Egharevba (1979) reported the use of sorghum in local recipes like tuwo, akamu and kunu in Nigeria. Even though sorghum adapt to wide ecological conditions the yield still remains low under the traditional farming practice. Several workers suggested improved management practices in order to increase the yield of sorghum. This include using optimum plant population Dogget PAT 2008; 4 (2): 66-73 ISSN: 0794-5213 Online copy available at www.patnsukjournal.com/currentissue