Correlation of Foliar Nutrient Status with Yield of Sugarcane Varieties at Different Crop Stages and Nitrogen Levels at Wonji-Shoa and Finchaa Sugarcane Plantations of Ethiopia
Main Article Content
Abstract
A study was conducted at Wonji-Shoa and Finchaa sugarcane plantations to determine criticaland optimum foliar N level and identify effect of N fertilizer rates, cuttings and varieties onfoliar N, P and K composition at different age of cane. Field trials were conducted from 2000to 2006 on vertisol and fluvisol at Wonji-Shoa and vertisols and luvisols of Finchaa. Threefactor randomized complete block design with three replications was used. The treatmentswere arranged in split split plot by assigning nitrogen rates as main plot, crop stage (PC, I andII ratoons) as sub plot and varieties as subsub plot. The result indicated that cane and sugaryield across cutting consistently decreased from plantcane to the subsequent ratoons inaddition the foliar N content of the ratoons were lower than the plantcane in both sugarcaneplantations. Moreover, in both sites the foliar N, P and K levels decreased consistently fromthe 3 months to the 6 months cane. Cane and sugar yield of Wonji-Shoa was positively andsignificantly (P<0.05) correlated with foliar N % at 4 month age, while at Finchaa cane andsugar yield was positively and significantly (P<0.05) correlated with foliar N % from 3 to 6months cane age with strong correlation at 5 months of age. It was suggested that thestandard foliar sampling time to be 4 month at Wonji-Shoa and 5 month at Finchaa as long asthe standard fertilizer application time was maintained 4 to 6 weeks before leaf sampling. Thecritical foliar nitrogen levels of Wonji-Shoa and Finchaa sugar estates were 1.66 % and 1.82 %,respectively, and the optimum foliar N range were 1.68-1.74% for Wonji-Shoa and 1.83-1.85 %for Finchaa. In addition the foliar N levels vary among cutting and variety therefore;adjustment should be made before interpretation.