Abstract:
Afield experiment was conducted for two seasons at the college of Agricultural studies, Sudan University of Science and Technology in Khartoum (Shambat ), during summer season of 2012 /2013, to study the effects of sowing date , nitrogen rate and nitrogen use efficiency on yield of sorghum (sorghum bicolor L.). The cultivar used was Wad Ahmed . The experiment was laid in spilt plot arrangement in a randomized complete block design (RCBD) with three replications . The main plots were four sowing date on 1st July (S1), 15th July (S2) ,1st August (S3) and 15th August (S4) . Subplots were four nitrogen rates : control (No) , 45 Kg N/ha (N1),90 Kg N/ha (N2) and 135 Kg N/ha (N3) . Growth parameters studied were plant height, leaves number /plant and leaf area . Yield components studied were length of head, weight of seeds /plant, 100.seeds weight, grain yield, harvest index and nitrogen use efficiency . The results showed that sowing date had significant effect on leaf area, harvest index in both seasons, leaves number/ plant and grain yield in
season one, length of head and weight of 100seeds in season two . Application of fertilizer resulted in significant effect on grain yield and nitrogen use efficiency in both seasons, leaves number in season two .
