Selection of suitable wavelength bands for discrimination between parts of plant body using their spectral reflectances.

In this study, spectral reflectances of parts of fruit vegetables were measured and degree of discrimination between them in some pairs of wavelength bands was calculated in order to distinguish each part of fruit vegetables from others. The results were given as follows:1. Spectral reflectances of all leaves which were measured in this time were almost similar, but those of different color fruits were different in the visible region and those of all fruits could be classified into higher type and lower type than their leaves in the near-infrared region. Reflectances of flowers were different in the visible region, and those were similar in the nearinfrared region. Water absorption bands were observed at 970 nm and 1170 nm wavelength only in fruits and stems, and were observed at 1450 nm and 1950 nm in all parts.2. 670 nm wavelength was effective for discrimination of fruit whose color was red or yellow such as a tomato, 800-900 nm was for fruit whose reflectance was higher than the other parts in the near-infrared region such as a eggplant or a cucumber, 1950 nm was for a eggplant stem, and 1450 nm was for a sweet pepper fruit. It was considered that the discrimination became easier when these wavelengths were combined with another characteristic wavelength.