Practical Use to Satsuma Mandarin Cultivation of the Red Edge Wavelength of Leaves

摘要

It is effective to artificially control the water stress for trees in cultivation of the Satsuma mandarin in order to the production higher sugar content fruits. It is known that the water stress will cause the blue shift of the red edge wavelength of leaves. In the present paper, the authors prepared the field with various water stressed trees, and they investigated the movement of the red edge wavelength of leaves and the sugar content of fruits. The results of measurements suggested an adequate correlation (R~2=0.8909) between the red edge wavelength and the sugar content. The authors also developed the prototype of a measuring device, which can estimate the water stress factor from the blue shift of the red edge wavelength using the spectrum analysis.