An Attempt to Assess Leaf Color of Winter Cereals Using a Simple Video System

[摘要] The estimation of the chlorophyll content of leaves of wheat, barley and rye was attempted using an 8 mm video camera and a personal computer system. First, we took video images of a color chart for rice leaf from various directions outdoors, and the variation of R (red), G (green), and B (blue) signals of the images was investigated. The signals varied extremely with every direction of the camera in fine weather, but were relatively stable in cloudy weather. For this reason, the estimation of chlorophyll contently video image was examined in cloudy weather. The images of wheat, barley and rye were gathered on five cloudy days. The relationships between the signals from the image and the chlorophyll contens were examined. Among the several functions of the signals, the highest correlation (r=-0.84 to -0.96) was found in R-B or G-B within the day of each investigation. However, the highest correlation (r=-0.81) was found in (R-B)/(R+B), when all results were combined. Moreover, almost the same regression line was obtained for (R-B)/(R+B) regardless of the investigation day and the species. From these results, the possibility of the assessment of leaf color by video image was discussed.

[学科分类] 农业科学（综合）

[关键词] Barley;クロロフィル;Chlorophyll content;ビデオ画像;Leaf color;麦類;Remote sensing;葉色診断;Rye;リモートセンシング;Video image;Wheat