t is well known that plants need water, mineral salts, carbon dioxide, and light to make their own food, thus allowing their survival and growth.
The multiple uses that light has in the technological field, the base pillar that is light in agriculture, and the need to increase production and productivity in the globalized world in which we live, places light as a key tool in development of new agricultural techniques.
Some of the technologies related to light that are used in agriculture are radiometry, spectrophotometry, colorimetry, LED lighting, etc.
But ... why is light management important in agriculture?
Because parameters such as quantity, type of light, and exposure time influence plant growth.
The amount of light will determine the speed of the photosynthesis process, thus influencing the growth rate of plants. The type of light, or rather the spectral range of the radiation will determine the type of interaction with the plant. For example, visible radiation is absorbed by chlorophyll allowing the development of photosynthesis, ultraviolet radiation that can cause DNA damage, decrease flowering and seed development, or ultraviolet A radiation that can cause elongation of the plant. In addition, depending on the type of plant, to trigger the flowering you will need the duration of the radiation to be more or less abundant depending on the case.
Thus, variations in the use of light could improve the shape and color of the plants, the earliness of the harvests, or improvements in the control of pests and diseases. When natural light is not enough, you want to grow species that usually develop in other areas and seasons, or even indoor crops, artificial sources are used, in which case LED lighting stands out for its efficiency, long life, variety of lengths. emission wave with narrow spectra that allow concentrating all the energy in the wavelength where the efficiency of interaction with the plant is greater.
The study of how different parameters of light affect a specific crop is very relevant to help farmers increase the quality and yield of their crops. In addition to adding artificial light as a supplement, some radiation can be of little benefit to certain crops. A solution to this problem is the photoselective meshes, which are covered with optical properties to select which components of the solar radiation let through to the crops, being able to improve the quality of the fruits or protect from pests.
In addition to the use of light on the crop, there are also applications with light that are already being implemented in the agricultural field, where disinfection by the ultraviolet radiation of air, water, and surfaces stands out (some of which may be the harvested vegetables themselves, in order to avoid rotting quickly).
So is the light just for treatment?
The truth is that no, the light also works as a recognition and detection tool. Among them, the use of colorimetry to determine the degree of maturity of some fruits or the use of spectral signatures both on food and on crops stands out.
What are spectral signatures and what are they for?
Spectral signatures are a method in which the reflected intensity is collected for different wavelengths, registering a spectrum that will be different depending on the pigmentation of the leaves or other factors that may be related to the state of the plant. In this way, differences in the spectra can serve as an indicator of symptoms that plants present, although not necessarily the causes that provoke them, for which multispectral image correlation studies with other types of analysis are required.
In short, light is a form of energy with the versatility of use in treatment and detection tools in all kinds of areas, and in the case of the agricultural sector, there is a wide range of techniques that can revolutionize its development.
BEATRIZ MENÉNDEZ
RESPONSIBLE FOR RADIOMETRY AND COLORIMETRY - FOTOGLASS
FOTOGLASS is a leading bio-optics company combining physical optics and biomedicine. Its activity focuses on the use of light as a tool to solve problems in a living environment, such as the inactivation of pathogens by ultraviolet C, the ability to accurately discern between tumor and non-tumor tissue by nanoplasmonic technology, the use of chromatography within food or the creation of smart textiles. It collaborates with the Marqués de Valdecilla University Hospital and the University of Cantabria. For more info: https://www.fotoglass.es