Abstract:
Lemongrass (Cymbopogon citratus DC. Stapf. ) a tropical grass that belongs to the family Poaceae (Gramineae) is one of the most important medicinal and aromatic plants. It produces an essential oil which has a high economical value. Lemongrass can be successfully produced in Sudan at a commercial level. This study was carried out to investigate the effect of urea fertilizer on the vegetative growth, herbage yield and oil content of lemongrass (Cymbopogon citratus). An experiment was conducted at the Department of Medicinal and Aromatic Plants of Horticulture Sector Administration, Khartoum, Sudan, during the period from August to November of the year 2015. The treatments of this study consisted of two doses five levels of urea (1.0, 2.0, 3.0, 4.0 and 6.0g urea /plant) and the control (no urea). The treatments were arranged in a completely randomized design with four replications. The fertilizer was applied to the plants which were already growing in plastic pots measuring 34×32 cm. The plants were cuts to the level of the soil and the fertilizer was applied immediately. The parameters measured are the plant height, the number of tillers per plant, the number of leaves per plant before and after first cut and the oil contents at the two cut. The first cut was 30 days after the fertilizer application and the second cut was 60 days after the first one and the second dose of the fertilizer. Application of urea had significant effects on vegetative growth and herbage. The fertilizer application resulted in a significant difference in oil content in the first cut, while the second cut was not greatly affected with respect to oil content. The best result was obtained by the application of 3.0 g urea/plant in plant height, 4.0 and 6.0 g/plant regarding the number of tillers and 3.0, 4.0 and 6.0 g/plant for number of leaves per plant. All fertilizer treatments resulted in significantly more values of these parameters than the control. With respect lemongrass oil content, there was significant difference in the first cut, whereas the second cut showed no significant differences among the treatments. Although the percentage oil content showed no significant difference, the total oil content seems to be affected.
