There are numerous laser applications on medicinal and aromatic plants. In order to perform optimal effects of laser radiation on the plant, it is necessary to determine precise parameters of laser-material interaction. In the paper, the selected materials of medicinal and aromatic plants were exposed to laser irradiation with varied wavelengths and the reflection coefficients of the plants were determined.
The lasers have been used for longer time in biology, due to stimulating effects of their radiation on plants' growth. The laser could find its applications for medicinal and aromatic plants in biostimulation, diagnostics, processing etc. The particular wavelengths have been applied in different laser operating regimes as extension of previous experiments with natural noncoherent light, but the effects being observed with coherent light are much stronger. Diagnostic laser applications can be classified as automatic and numerical methods designed for the shape recognition, or classified on physical methods based on static and dynamic light scattering, radiation reflection and absorption, linear and nonlinear laser spectroscopy etc.
Laser methods can be applied to determine the content of water in a plant as well as to determine different physical characteristics (electrical, magnetic, acoustic and optical) that enable appropriate diagnostics of plant's state [1]. In this work, the reflection coefficient of the plants is investigated as physical characteristic that is necessary in plants' treatment by the laser.
The specimens of the following materials were utilized in the work: Coriandri fructus, Althae radix, Melissae folium, Menthae piperitae folium, Valeriane radix and Foeniculi fructus.
The materials were subjected to reflection spectrophotometric analysis. When investigated sample is exposed to the light with intensity I0, the light divides on the reflected Ir, absorbed Ia and transmitted It part that are characterized with corresponding coefficients: reflection coefficient r= Ir / I0, absorption coefficient a = Ia / I0, transmission coefficient t= It / I0, where r + a + t = 1.
Reflection spectrophotometry enables to gain the information about the state of examined plant material according to its reflection spectrum r(l). Reflection spectrum is defined as the dependence of reflection coefficient on light wavelength l. Therefore, it is possible to determine r(l) by measuring the intensities of incident and reflected light by spectrum photometer i.e. specific device designed to measure r(l) by special analogous method.
The results of reflection spectrofotometry for the given materials are presented on the Graphs 1-6. The reflection coefficients of particular plant are given in the function of laser wavelength.
The laser can produce mutagenesis due to its radiation and chemical effects [2-3]. Radiation can induce rough effects on genetic structure of cell and physiologic bio-chemical processes therefore inducing mutants and decreasing life ability. That makes negative effects in plant selection process, thus it is necessary mutagen (laser) optimization. Adjusting radiation wavelengths, TYE lasers as well as ruby, argon and other laser influence on pure nuclein DNK on 280 nm wavelength, proteins etc. where linear dependence of dose and level of mutagenesis is assumed.
The development of the lasers with wavelengths adjustable to resonant effects on bonding energies in molecular world and susceptibility of plants' photons, the numerous approaches in laser applications including complete visible, ultraviolet and infrared light spectrum as well as X and gamma rays e.g. in order to induce sterilization effects or longer conservation of specific plant performances, to perform remote content control of the plant or the surrounding air, microbiology analysis, etc.
There are numerous laser applications on medicinal and aromatic plants. In order to perform optimal effects of laser radiation, it is necessary to determine precise parameters of laser-material interaction. In the performed work, the selected materials were subjected to laser irradiation and their reflection coefficients were determined for defined range of light wavelengths. Reflection coefficient is important parameter in specifying laser dosimetry in plants' treatments such that is plants' bistimulation, diagnostics, processing etc in order to induce optimal effects on plants. Seeds were also exposed to laser radiation and planted, therefore the effects of laser beam will be known after the plant growing cycles.
Zucher E. (1988): Diagnosen Metoden Gesundheit und Vitalitaetszustande. Vierteljahris-schrift der Naturvorschenden Geselchaft in Zuerich 1.33/1, 25-42.
Volodin V. G. and Mostovnikov V. A. (1984): Laseri i nasledstvenost rastenii. Nauka i tehnika, Minsk.
Rvatchev V. P. (1978): Metodi optiki svetorasejvajeshschih sred v fizike i biologii. Izd. BGU, Minsk.