Determination of optimum seed rate for the production of sesame (Sesamum indicum L.) in the lowlands of North Shewa, Ethiopia

On-farm study was conducted in the lowland areas of Kewot district in the North Shewa Zone, Ethiopia on two sites during 2011 crop season to determine optimum seed rate of sesame. Four seed rates (2, 4, 6 and 8 kg ha-1) of sesame cultivar Adi, were arranged in a randomized complete block design (RCBD) with four replications at each experimental site. The results of analysis of variance showed that location and seed rate had no significant effect on grain yield and plant height. Similarly, interaction of seed rate and location had no significant effect on grain yield, plant height and number of branches plant-1. On the other hand, location and seed rate had significant (p≤0.05) effect in the number of branches plant-1. The maximum number of primary branches plant-1 (3.3) was obtained from the seed rate of 2 kg ha-1 and the minimum number of primary branches plant-1 (2.3) was obtained from the seed rate of 8 kg ha-1. Since the statistical analysis revealed non-significant difference among treatment yields, comparison was made by using total costs that vary. Accordingly, 2- 4 kg ha-1 seed rate found to be optimum for the production of sesame under rain-fed condition around Kewot district and similar areas.   Key words: Adi, broadcast, Kewot, Medina, under rain-fed, Yelen crossing.