Abstract
Pollinated flowers, which exist randomly among Gentiana Sp. cut flowers, are the main cause of decreased market values. Because such flowers often arrive at market with their color changed to copper from its original color, there is a very high risk that the value of the whole bunch is diminished. For this reason it is necessary to remove pollinated flowers in the interval between harvest and shipment. Currently most farmers manually carry out this laborious process, and often not all of the pollinated flowers are detected and removed. In `Ashiro no natsu', which is the leading Gentiana sp. variety in Iwate prefecture, the visible difference between a young flower and a flower which has just been pollinated in the field is so subtle that removal of the pollinated flower is extremely difficult. On the other hand, even in this variety, a few skillful farmers can detect pollinated flowers with careful inspection. However, to spread their skill, it is necessary to objectively elucidate their technique for making the distinction. In this study targeting `Ashiro no natsu, Gentiana sp.', spectral radiance differences between young flowers and pollinated flowers on the outer surface of petals was examined closely with a simple measuring device over wavelengths ranging from visible to infrared. A significant difference was identified at wave lengths in the neighborhood of 720 nm. Thus, in the near future it will be possible to develop an early detection device for pollinated flowers using inexpensive digital photography because CCD, the image sensor used in most commercial video cameras, is sensitive to this wave length.
