Effect of Urea Fertilizer Rate on Growth and Yield Components of Sorghum (Sorghum bicolor L.) under Rain – fed Conditions, in North Kordofan, Sudan

Low soil fertility is one of the main factors for low productivity of crops in North Kordofan State. The effects of urea fertilizer on growth and yield of sorghum (Sorghum bicolor L.) variety Botana was studied at the experimental field of Faculty of Natural Resources and Environmental Studies, in Sheikan locality, North Kordofan State during two consecutive rainy seasons 2021/2022 and 2022/2023. The experiment consisted of three treatments (Control, 40kg urea/feddan and 80 kg urea /feddan). Treatments were laid out in a Randomized Complete Block Design (RCBD) with four replications. Growth characters studied were (days to 50% flowering, plant height (cm), number of leaf per plant, leaf area index and stem diameter (cm). Yield and yield attributes were straw dry yield (ton/ha), full head dry weight (g) 1000 seeds weight (g), grain yield (ton/ha) and harvest Index (%). Data were analyzed using GEN STAT program. Means were separated using Least Significance Difference (LSD) at 5% probability level. Results showed that urea fertilizer significantly (P<0.05) increased sorghum plant growth, yield attributes and grain yield compared to control in both seasons. Urea fertilizer significantly (P<0.05) decreased days to 50% flowering and increased plant height (cm), straw dry yield (6.5 ton/ha) compared to control (4.7 ton/ha), 1000 seeds weight (g), grain yield (2.3 ton/ha) compared to control (1.9 ton/ha) and Harvest Index% for sorghum crop. Whereas there was no significant effect amongst treatments on number of leaf per plant and stem diameter (cm). It was concluded that application of urea had a significant effect in most studied attributes in addition to shortening the maturity period. Therefore, to increase yield and yield components of Sorghum, namely cultivar Botana, in the study area during rainy season's application of urea is recommended.