Abstract
Quantification of leaf spot (leaf damage with yellow spot) in Saintpaulia (Saintpaulia ionantha H. Wendl. cv. Ritali) was conducted by using an image analysis technique. Clear images without distortions or shadows were acquired by using a transmitted light from underneath the leaf. Quantification by the image analysis has very high correlation with that estimated by weighing the replicas of photograph. Furthermore, images analyzed by using an image editing software corresponded very well with the micrograph photographed under a fluorescence microscopy. These results indicate that the proper use of the transmitted light can provide precise quantification of leaf damage, even if it is characterized by a very complex pattern as leaf spot in Saintpaulia.
