Photoluminescence monitoring the ripeness of cereal seeds during ripening

Introduction. To assess objectively the ripeness plant seeds is one of the areas of developing agricultural electrotechnical technologies. Optical methods and diagnostic tools are highly accurate, selective, and express, and can be easy integrated into existing modern agricultural machines and devices. Materials and Methods. The exploratory research of optical spectral luminescent properties of cereal seeds of defferent ripeness levels was carried out. The lots of oat and wheat seeds of the milky, milky-wax, and waxy ripeness, as well as ripe seeds were selected. The study was conducted on the spectrofluorometer "Fluorat-02-Panorama". The spectra of synchronous scan excitation were measured based on the seed luminescence spectra. The integral parameters of the spectra were calculated. Results. The seeds of milky ripeness have the highest peak of excitation at a wavelength of about 362 nm and significantly less values at 424 nm. In ripe seeds there is no short-wave peak (Xmax = 362 nm). There are remain peaks of 424 nm and 485 nm, and the long-wave peak increases with increasing ripeness. With increasing seed ripeness, the ratio of longwave to the shortwave flux increases. The dependences can be statistically reliably approximated linearly. The obtained dependences can be used to determine the seed physiological ripeness degree. There have been proposed a technique for determining the ripeness of cereal seeds during their riping, including sample preparation, excitation of luminescence in the short-wave and long-wave ranges, its registration, amplification and processing the resulting photoelectric signal. To implement the method, the design of the device for objective rapid analysis of the stage of seed physiological ripeness was developed. Discussion and Conclusion. During the ripening of cereal seeds, the ratio of their excitation levels and luminescence fluxes changes: for immature seeds, short-wave luminescence is characteristic, while in mature seeds, long-wave luminescence prevails. The dependence of the ratio of photoluminescence fluxes on the ripeness time is an increasin-gone. A device for determining the seed ripeness stage is developed.