Grain, Oil Yield and Nitrogen Use Efficiency in Different Varieties of Sesame (Sesamum indicum L.) under Nitrogen Fertilizer and Weed Competition

In order to evaluate the effect of different amounts of nitrogen fertilizer on oil and porotein content and nitrogen use efficiency of five sesame varieties under weed competition condition, this study was carried out at Omidieh (Boshehr province) during summer of 2013. Treatments were arranged in split factorial based on RCBD with three replications. The main plot consist of nitrogen fertilizer application levels as control, non application and application of 50 and 100 kg.ha-1 nitrogen from urea form and subplots were in a factorial combination of sesame varieties (Behbahan landrace, Yellow-white, tn-238 and tn-240) and weed competition (weed free and weed infest) . The results showed that the effect of nitrogen fertilizer on grain yield of different sesame varieties was significant. The highest grain yield (220 g.m-2) was obtained from Behbahan landrace with 100 kg.ha-1 nitrogen application under weed frees condition and the lowest was achieved from tn-238 and tn-240 lines without nitrogen application under weed infests condition. The highest oil percent (44%) was belonged to tn-238 line whitout nitrogen application and the lowest (35%) was achieved from Yellow-white variety with 100 kg.ha-1 nitrogen application. Also the highest oil yield (83 kg.ha-1) was belonged to Behbahan landrace with 100 kg.ha-1 nitrogen application under weed free condition. Increasing the nitrogen fertilizer application decreased nitrogen utility efficiency. The highest nitrogen utilisation efficiency achieved from Behbahan landrace in no nitrogen fertilizer application.