2005 Volume 67 Issue 4 Pages 90-96
Potential of near infrared (NIR) spectroscopy to measure the potassium content in sugarcane juice was investigated in order to produce high quality sugarcane using precisely controlled fertilizer applications. Although there was no absorption due to minerals in the range of near infrared, sucrose content and 14 minerals in juice samples were measured to specify the wavelength used for the potassium calibration equation. Applying MLR (Multiple Linear Regression) to absorbance at each wavelength, a highly correlated wavelength at 1820nm to the potassium content was obtained, which had no correlation to the sucrose content. Calibration equation by PLSR showed higher correlation than that by MLR. The standard error of prediction (SEP) was 161.8 ppm and Bias was -41.7 ppm as validation results. It could be concluded that NIR spectroscopy was useful to determine the potassium content in sugarcane juice.
