The Influence of Composite Luminescent Materials Based on Graphene Oxide on the Growth and Development of <i>Solanum lycopersicum</i> in Greenhouses

The effect of graphene oxide-based photoconversion covers on the growth and photosynthesis of tomatoes (Solanum lycopersicum) was investigated. Two types of photoconversion composite for covers were produced. In the first, only graphene oxide nanoparticles were used as a phosphor, and in the second, the graphene oxide nanoparticles were used jointly with europium oxide nanoparticles. The freshly prepared composites for covers had almost identical photoluminescence spectra: an intense peak in the red region and a minor peak in the blue region. It was revealed that during operation, luminescence in the red region decreased, while in the blue region it increased, probably due to the photothermal reduction of graphene oxide. It was shown that the photoconversion covers increased productivity (25%) and intensified photosynthesis (30–35%) in the tomato plants. It is suggested that the stimulation of plant growth is caused by changes in the light spectrum induced by the photoconversion covers

Application of the Impedance Measurement Method to Evaluate the Results of Winter Grafting of Pear Cuttings Using Cold Plasma

Electroimpedance spectroscopy technology can be used to accelerate the healing of complete trees and estimate the plant condition after grafting. This approach will allow sorting out low-vigor plants at the early stages of their development to save time and resources. Still, in some cases, the use of electrical impedance spectroscopy can be difficult due to the complexity of the equipment and special measurement conditions. In this paper, we attempt to overcome this limitation by suggesting a compact device developed in-house that is usable even in the field. Pear (Pyrus communis L.) Otradnenskaya was used as the object of this study. We assessed the treatment effect of the scion–rootstock interface with cold atmospheric plasma (CAP) and plasma-treated solution (PTS) on the survival of the grafts. The dependence of the impedance of the complete grafted tree on the signal frequency and the length of the measuring section was analyzed. It is shown that the treatment of the scion and rootstock with CAP and PTS promotes the fusion of scion and rootstock. The impedance value in the control was on average 24–35% higher than in plants treated with CAP and PTS, which indicates a better healing process of the grafting site. This can be an indication of better quality of the planting material which can be obtained much earlier than with the conventional approach (monitoring the plants in a nursery)

Application of the Impedance Measurement Method to Evaluate the Results of Winter Grafting of Pear Cuttings Using Cold Plasma

Electroimpedance spectroscopy technology can be used to accelerate the healing of complete trees and estimate the plant condition after grafting. This approach will allow sorting out low-vigor plants at the early stages of their development to save time and resources. Still, in some cases, the use of electrical impedance spectroscopy can be difficult due to the complexity of the equipment and special measurement conditions. In this paper, we attempt to overcome this limitation by suggesting a compact device developed in-house that is usable even in the field. Pear (Pyrus communis L.) Otradnenskaya was used as the object of this study. We assessed the treatment effect of the scion&ndash;rootstock interface with cold atmospheric plasma (CAP) and plasma-treated solution (PTS) on the survival of the grafts. The dependence of the impedance of the complete grafted tree on the signal frequency and the length of the measuring section was analyzed. It is shown that the treatment of the scion and rootstock with CAP and PTS promotes the fusion of scion and rootstock. The impedance value in the control was on average 24&ndash;35% higher than in plants treated with CAP and PTS, which indicates a better healing process of the grafting site. This can be an indication of better quality of the planting material which can be obtained much earlier than with the conventional approach (monitoring the plants in a nursery)

Plant Photochemistry under Glass Coated with Upconversion Luminescent Film

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions

Plant Photochemistry under Glass Coated with Upconversion Luminescent Film

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions