ШЛЯХИ ПОБУДОВИ ЕНЕРГОЕФЕКТИВНИХ СВІТЛОДІОДНИХ СИСТЕМ ФІТООСВІТЛЕННЯ

Abstract

Lighting of plant crops (phytolighting) realized on the basis of LEDs has revolutionized the field of indoor agriculture and cultivation of crops in closed controlled environments due to the possibility of optimizing the spectral composition and high energy efficiency. The use of specialised quasi-monochromatic radiation allows the activation of specific photomorphogenic, biochemical or physiological responses in plants, while LED radiation of a specific spectral composition (e.g. UV radiation) allows the control of plant pests and diseases. The literature review indicates that there is a species- and cultivar-specific response of plants to light radiation of a particular spectral composition and that this response varies with the stage of plant development, the intensity of illumination, the duration of plant development and specific interactions with the environment. Based on the developed recommendations for the spectral composition of radiation intended for plant illumination, the requirements for the spectral composition of light for phytolighting systems were determined. The efficiency of LEDs with different spectral compositions for plant illumination and the most energy efficient LEDs for use in phytolighting systems were determined. Special software was developed to determine the photon radiation efficiency and it was determined for a wide range of LED light sources. The LEDs studied had photon efficiencies ranging from 3.78 μmol/J (quasi-monochromatic blue LEDs) to 5.46 μmol/J (quasi- monochromatic red LEDs). White LEDs, depending on their colour rendering index, had a photon spectral efficiency in the range of 4.62-4.79 μmol/J. Some modern white LEDs with a high colour rendering index have a photon spectral efficiency close to that of phytolighting based on special quasi-monochromatic LEDs, but their efficiency, taking into account the weighting factor of the use of photons of different wavelengths for photosynthesis, is much lower.