Estimation of Lipid Concentration in Aerial Maize Tissues at Different Growth Stages by Near Infrared Reflectance

Abstract

AbstractNear infrared reflectance (NIR) spectroscopy is a rapid, inexpensive, and simple technique used to make quantitative analyses of the concentration of nutrients in plant tissue. In this field experiment, the potential usefulness of NIR analysis for the study of lipid concentrations in the aerial plant tissues of maize (Zea mays L.) was evaluated using a fairly simple and inexpensive NIR unit (Inframatic 8100, Per Con Prügeräte GmbH, Germany). Lipid concentration values were measured by standard Soxhlet techniques, which were used to calibrate the instrument for plant samples taken at tasselhng, 3 weeks after pollmation, and plant maturity. Reflectance readings, obtained using seven filters, were fitted to Soxhlet values using multiple linear regression, and regression constants were obtained. The results showed that correlation coefficients between Soxhlet lipid concentration and NIR value obtained were 0.999 and 0.995 for grain lipid and stover lipid, respectively. Standard errors of the estimated values were 0.5929and 0.5562for maize grain and maize stover when the six wavelengths were used, indicating a level of accuracy sufficient for analytical purposes.