Non-radiative relaxation time of lettuce seed obtained by photoacoustic spectroscopy

C. Hernandez Aguilar1,2, A. Dominguez Pacheco1,2, A. Cruz Orea2 and F. Sanchez Sinencio2,3

1Instituto Politécnico Nacional - ESIME zacatenco, Mexico
3Centro Latino-Americano de Física

Keywords: photoacoustic
property: non-radiative
material: seed

The laser treatment is one of the physical methods that can improve the sowing quality [1-4] and food, help achieve higher productivity, and at the same time reduce the risk of contamination from soil and water [5]. The effects of biostimulation in seed depend on several parameters: the seed characteristics, the position of the seed during the laser irradiation, and the laser irradiation parameters. Regarding the seed characteristics, the: optical absorption coefficient (beta), optical penetration length (1/beta); and non radiactive-relaxation time (tau) are important. Therefore, the objective of the present research was to determine the optical absorption coefficient and the non-radiative relaxation time of lettuce seed, at wavelength (lambda)of 650nm. The beta and tau values were determined by photoacoustic spectroscopy measurements (PAS) [6-7]. Germination test was established with prior to sowing seed irradiated with diode laser wavelength of 650 nm and a modulation frequency equal to the inverse of relaxation time, have multiple and submultiples of the frequency modulation, making a total of 9 different seed treatments more control (non-irradiated seed). The time of radiation exposure was one minute. The obtained tau values could be important in the exposition times used in biostimulation by laser irradiation to improve the efficiency of these processes, due to the fact that the cells in the seeds are able to absorb, transform and use the energy of light photons in short times (ms).

  1. K. Klimont, Influence of laser light on crops and quality of amaranth (Amaranthus cruentus L.) seeds. Proc. Conf. Agrolaser, September 26, Lublin, Poland (2001)

  2. L.G. Paleg and D. Aspinall, Nature, 5275, 970, (1970).

  3. C. Hernandez A., A. Carballo C., A. Artola, A. Michtchenko. Seed Sci. Technol.34,193 (2006).

  4. C. Hernandez A., A. Domínguez P., A. Cruz-Orea, R. Ivanov, Int. Agrophysics. 23, 327 (2009).

  5. A. Aladjadjiyan, Case studies in food safety and environmental health integrating safety and environmental knowledge into food studies towards european sustainable development. Chemistry Materials Sci., 6, 69 (2007).

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