Seed Rate and Nitrogen Fertilizer Effects on Weed Biomass, Growth and Yield of Two Sesame (Sesamum indicum L.) Varieties

Abstract

Field experiments were conducted in the wet seasons of 2009 to 2011, at the Research Farm of the Institute for Agricultural Research, Ahmadu Bello University, Samaru (110 11′ N, 070 38′ E), in the northern Guinea savanna zone of Nigeria, to evaluate the influence of seed rate and nitrogen fertilizer on weed biomass, growth and yield of two sesame (Sesamum indicum L.) varieties. The treatments consisted of factorial combination of four seed rates (2, 4, 6 and 8 kg ha-1), four application rates of inorganic nitrogen (0, 30, 60 and 90 kg N ha-1) and two sesame varieties (NCRIBEN 01M and E8). The treatments were laid in a randomized complete block in a split plot arrangement with three replications. Seed and nitrogen rates were assigned to the main plot; while crop variety was assigned to the sub plot. Variety E8 in general reduced weed biomass, than NCRIBEN 01M. Conversely variety E8 produced the highest seed yield (6.5 %) compared to NCRIBEN 01M. Seed rates of 2 kg ha-1 gave lower weed biomass while 8 kg ha-1 produced taller plants, more number of capsules and highest seed yield. Seed yield increased with increase in seed rate such that it was 68.8 %, 60.1 % and 48.4 % for 8, 6 and 4 kg ha-1 over the 2 kg seed ha-1, respectively. Nitrogen rates had no significant effect on weed biomass produced. However, application of 90 kg N ha-1 produced taller plants, more capsules per plant and highest seed yield. Seed yield increased with increase in application of nitrogen such that it was 48.4 %, 42.1 % and 22.4 % for 90, 60 and 30 kg N ha-1 over 0 kg N ha-1, respectively. From this study it was observed that the use of 8 kg seed ha-1 together with the application of 90 kg N ha-1 and E8 was promising for weed growth reduction and maximum seed yield and may be recommended for higher production of sesame in the northern Guinea savanna of Nigeria.