High nitrogen levels in sugar beet leaves detected in the growing final stage can be an indicator of late incorporations of nitrogen from organic matter from soils or fertilizers. These tardy uptakes are known to decrease sugar yields. Among the different ways to measure nitrogen status in crops, here chlorophyll content determination using vegetation indices is explored. In this study, pictures of sugar beet leaves taken with a commercial camera were used to calculate 25 RGB indices found in bibliographic review and to obtain two new indices. The performance of studied indices are examined to evaluate its ability to measure chlorophyll content and degradation for sugar beet leaves in different natural light conditions along 4 days at final cultivation stage.