Evaluating Nitrogen Use Efficiency on Cane Yield, Yield Components and Quality of Two Sugarcane Genotypes under Agro-Ecological Conditions of Kenana Estate (Published)
Sugarcane (Saccharum officinarum L.) productivity and sucrose accumulation are critically dependent on nitrogen (N) availability; however, optimal N management remains challenging, particularly for newly introduced genotypes under specific agro-ecological conditions. This study was conducted to evaluate the effects of five N application rates (0, 164, 219, 274, and 329 kg N ha⁻¹) in the form of urea on the yield, yield components, and quality attributes of two commercial sugarcane varieties (R 579 and TUC75-3) at the Kenana Sugar Company Estate, Sudan. Two field experiments were established over consecutive growing seasons using a split-plot design with a randomized complete block arrangement and four replications, wherein varieties were assigned to main plots and N levels to subplots. Measured traits included stalk height, number of internodes, stalk diameter, stalk population density, cane yield (t ha⁻¹), sugar yield (t ha⁻¹), Brix, Pol, fiber content, estimated recoverable sucrose (ERSC), purity, and moisture content. Analysis of variance revealed highly significant effects of N rate on stalk height, internode number, stalk diameter, cane yield, and sugar yield (P < 0.01). In contrast, varietal differences were statistically significant solely for moisture content (P < 0.05), whereas a significant variety × N interaction was detected for purity (P < 0.05). Cane and sugar yields exhibited a positive, linear response to increasing N supply, with maximum cane yield (123.97 t ha⁻¹) recorded at the highest N rate (329 kg ha⁻¹), compared with 73.33 t ha⁻¹ under the unfertilized control (0 kg N ha⁻¹). Although variety R 579 consistently yielded numerically higher mean cane (109.83 t ha⁻¹) and sugar (16.77 t ha⁻¹) yields than TUC75-3, these genotypic differences were not statistically significant. Collectively, these findings demonstrate that N fertilization exerts a predominant influence on agronomic productivity relative to genotype selection under these edaphic conditions; nevertheless, the cultivar-specific response in juice purity merits consideration for targeted sugar recovery optimization.
Keywords: Sugarcane, cane yield; sugar yield, juice purity, nitrogen rates, variety evaluation.