When applied to seeds and plants, low intensity laser irradiation, which is widely used in different areas, such as physics, medicine and engineering, can improve the development, strength and quality of many crops of agro-industrial interest.
According to the research of an interagency group of experts, biological stimulation with various types of lasers, and within certain irradiation parameters, can benefit planting in adverse conditions affected by UV radiation, drought, cold, salinity, or metal contamination.
The research team is composed of Alfredo Cruz Orea, from the Department of the Physics Research Center and Advanced Studies (CINVESTAV) and experts from the School of Mechanical and Electrical Engineering (ESIME), the National Polytechnic Institute (IPN), the Autonomous University of Zacatecas, the Graduate School, and the School of Higher Studies Cuautitlan, among other institutions.
"We characterized the seeds to determine their optical absorption spectrum, (i.e. what wavelengths (colours) have increased light absorption) at the Cinvestav. We also determined how much the laser penetrates them - whether it only touched the surface or if it penetrated the seeds," the physicist stated.
To complete this phase of the analysis, in which they worked on samples of different products, such as corn, wheat, beans, lettuce, and tomato, he said, the researchers used a photo acoustic spectrometer.
The data obtained allowed researchers to have a reference that would help them define what the optimal doses and radiation intervals are in each case, he said.
Laser irradiation has been experimentally used in numerous crops since the 1960s, although most of the studies have been concentrated on wheat. Initially scientists employed ruby lasers and subsequently they tried helium-neon, argon, carbon dioxide, and neodymium lasers.
However, they now have laser diodes, which are much more efficient and less expensive than the others, he said.
Irradiance levels (hundreds to thousands of milliwatts) and exposure periods (from 0.1 to 10,800 seconds) vary depending on the type of laser used, its wavelength, and the plant species being treated.
Experts believe that applying this technology on an industrial scale could increase food production and crop yields and help meet the challenges posed by climate change and population growth.
This could be done in an economic and sustainable manner, as it would reduce the use of agrochemicals, according to an academic article on laser biostimulation of seeds and plants published recently.
"Laser biostimulation mechanisms, as well as the micro and macro effects simulations of the behaviour of agricultural seeds (according to their characteristics) should be further studied to predict the optimal irradiation parameter levels that produce favourable effects," added Cruz Orea.
Source: Notimex