Photoconversion Fluoropolymer Films for the Cultivation of Agricultural Plants Under Conditions of Insufficient Insolation

Glass-based LED system for indoor horticulture: enhanced plant growth through Sm3+ and Tm3+ co-doped luminescent glasses

This study addresses the challenges of sustainable and efficient agricultural practices in the face of climate change and the destruction of agricultural lands by presenting the development of a novel plant growth LED based on Sm3+ and Tm3+ co-doped luminescent glasses with color-converting properties that emit blue and red light, resulting in an increased rate of photosynthesis and density of photosynthetically active radiation reaching the harvesting pigments. The developed LED exhibits photoluminescence (PL) peak positions ranging from 454 to 648 nm, with a spectral coverage of 50% and 39% of the absorption regions of chlorophyll a and chlorophyll b, respectively, resulting in an impressive 56% photoluminescence quantum yield (PLQY). Furthermore, the developed plant growth LED demonstrates robust performance, remaining unaffected by temperature cycles and extended operation periods. Using Romaine lettuce cultivated under identical conditions, a comparative study between the developed LED and commercially available plant growth LED is conducted, with the designed LED showing significant improvements in plant growth characteristics, including increased plant height, weight, number of leaves, and enhanced levels of chlorophyll a, chlorophyll b, and carotenoid content, while the root diameter is reduced, and the shoot-to-root ratio is diminished in comparison to the commercially available plant growth LED. The paper also compares the performance of Sm3+ and Tm3+ co-doped luminescent glass-based plant growth LED with other reported plant growth LED designs using different luminescent materials, exploring the impact of PLQY, PL position, and plant growing conditions. The results suggest that the developed LED system offers a more efficient and sustainable way of lighting for indoor horticulture and has significant implications for meeting the increasing food demands of the growing world population.

Plant growth acceleration using a transparent Eu3+-painted UV-to-red conversion film

The stimulation of photosynthesis is a strategy for achieving sustainable plant production. Red light is useful for plant growth because it is absorbed by chlorophyll pigments, which initiate natural photosynthetic processes. Ultraviolet (UV)-to-red wavelength-converting materials are promising candidates for eco-friendly plant cultures that do not require electric power. In this study, transparent films equipped with a UV-to-red wavelength-converting luminophore, the Eu3+ complex, were prepared on commercially available plastic films for plant growth experiments. The present Eu3+-based films absorb UV light and exhibit strong red luminescence under sunlight. Eu3+-painted films provide significant growth acceleration with size increment and biomass production for vegetal crops and trees in a northern region. The plants cultured with Eu3+-painted films had a 1.2-fold height and 1.4-fold total body biomass than those cultures without the Eu3+ luminophores. The present film can promote the plant production in fields of agriculture and forestry.

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.

Varietal Characteristics of Jerusalem Artichoke as a High Nutritional Value Crop for Herbivorous Animal Husbandry

Jerusalem artichoke (Helianthus tuberosus L.) is considered to be one of the most promising multipurpose bioenergetic crops. The goal of this study was to carry out laboratory and field research regarding the tops and tubers of 16 Jerusalem artichoke (JA) cultivars grown on sod-podzolic sandy loam soils, taking into account varietal characteristics in order to point out advances in JA potential as alternative feedstock in herbivorous animal husbandry. The height of JA plants produced was from 147 to 280 cm. Having formed by the beginning of September, the size of the assimilating leaf apparatus surface was 0.41 to 2.31 m2/plant. In early September, the productivity of JA green mass amounted to 23.6 to 86.0 t/ha for late-maturing cultivars on average; correspondingly, this was 13.0 to 25.4 t/ha for early-maturing cultivars. At the end of October, the “late” cultivars produced 28.2 to 86.9 t/ha of green mass; on the contrary, the herbage of the “early” ones mostly withered and even dried up. The highest gross yield of tubers in early September was obtained from cultivars Diyeticheskiy (43.5 t/ha) and Nadezhda (40.8 t/ha). The average yield of early-maturing cultivars was 13.4 … 43.5 t/ha; as for “late” ones, it was reported to be 6.0 … 35.9 t/ha. In the third ten-day period of October, tubers of all cultivars gained weight significantly: the average yield of early-maturing cultivar tubers increased up to 33.1 …51.1 t/ha, whereas the average tuber yields of “late” cultivars were 14.4 … 43.9 t/ha. On average, the distribution of dry matter content in JA was 28.8 to 29.8% in aboveground biomass and in tubers, 23.8 to 24.0%. According to the chemical composition, cellulose (10.9 to 13.1%) and sugars (4.0 to 4.2%) could be noted to predominate in the green mass, but tubers were high in sugars (16.9 to 17.6%). The analyses on the trace elements (Ca, Fe, Mg, Mn, Si and Zn) showed that crop green mass contained more Mg (45 to 72 mg/100 g) and Mn (44 to 65 mg/100 g), but for JA tubers, late-maturing cultivars were rich in Si (27.2 to 79.0 mg/100 g) and early-maturing cultivars were mainly high in Zn (32.8 to 46.5 mg/100 g). The highest total coefficient of energy efficiency was displayed by the following cultivars: Novost VIRa (3.09); Tadzhikskiy (2.78); Spindle (2.68); Korenevskiy (2.43); Interes (2.10); and Skorospelka (1.98). In this respect, Jerusalem artichoke certainly has potential as a forage crop that can reach high yields with low external inputs. The data obtained may be useful for farmers who want to adapt and produce this useful and essential crop for the sustainability of feed production.

Luminescence of Agrotextiles Based on Red-Light-Emitting Organic Luminophore and Polypropylene Spunbond Enhances the Growth and Photosynthesis of Vegetable Plants

The impact of a light-transforming covering on photosynthetic activity and growth processes in lettuce and white cabbage plants grown in a glass greenhouse was studied. Plants were covered with agrotextile, a polypropylene (PP) nonwoven spunbond coated with polylactide varnish containing a new organic luminophore (LUM), which absorbs sunlight mainly in the 460-560 nm region and efficiently reradiates it in the red spectral region with a maximum at 660 nm. For comparison, simultaneously two references agrotextiles without LUM or containing a non-luminescent chromophore (ABS) with an absorption spectrum close to that of LUM were as well investigated. The use of the agrotextile with LUM resulted in a significant increase in total crude aboveground biomass for 32-, 33-, and 43-day-old plants on the average by 20-40%, and the photosynthesis rate increased on the average by 30-40% compared to the agrotextile without LUM. The use of the agrotextile with ABS mimicking the absorption of LUM also did not reveal a significant impact on photosynthesis and biomass accumulation in the plants as compared to the reference agrotextile coated only with the polylactide varnish. At the same time, the photosystem II activity (F _v/F _m and F'_v/F'_m quantum yields) was nearly the same in all experiments. When plants were grown under the light-converting agrotextile, the luminescent component of the converted light in the red spectrum region led to an increase in plant growth and photosynthesis rate, which is a fundamentally new result. Possible reasons for the stimulation of growth and photosynthesis due to the redistribution of the light spectral composition were analyzed. The use of covering materials containing luminophores similar to LUM can be promising in agrobiotechnology not only for green and vegetable crops but also for other field and greenhouse crops and various fruit bushes and trees.

Cultivation of Solanum lycopersicum under Glass Coated with Nanosized Upconversion Luminophore

The effect of upconverting luminescent nanoparticles coated on glass on the productivity of Solanum lycopersicum was studied. The cultivation of tomatoes under photoconversion glass led to an increase in plant productivity and an acceleration of plant adaptation to ultraviolet radiation. An increase in the total leaf area and chlorophyll content in the leaves was revealed in plants growing under the photoconversion glass. Plants growing under the photoconversion glass were able to more effectively utilize the absorbed light energy. The results of this study suggest that the spectral changes induced by photoconversion glass can accelerate the adaptation of plants to the appearance of ultraviolet radiation.

Additive Production of a Material Based on an Acrylic Polymer with a Nanoscale Layer of Zno Nanorods Deposited Using a Direct Current Magnetron Discharge: Morphology, Photoconversion Properties, and Biosafety

On the basis of a direct current magnetron, a technology has been developed for producing nanoscale-oriented nanorods from zinc oxide on an acrylic polymer. The technology makes it possible to achieve different filling of the surface with zinc oxide nanorods. The nanorods is partially fused into the polymer; the cross section of the nanorods is rather close to an elongated ellipse. It is shown that, with intense abrasion, no delamination of the nanorods from the acrylic polymer is observed. The zinc oxide nanorods abrades together with the acrylic polymer. Zinc oxide nanorods luminesces with the wavelength most preferable for the process of photosynthesis in higher plants. It was shown that plants grown under the obtained material grow faster and gain biomass faster than the control group. In addition, it was found that on surfaces containing zinc oxide nanorods, a more intense formation of such reactive oxygen species as hydrogen peroxide and hydroxyl radical is observed. Intensive formation of long-lived, active forms of the protein is observed on the zinc oxide coating. The formation of 8-oxoguanine in DNA in vitro on a zinc oxide coating was shown using ELISA method. It was found that the multiplication of microorganisms on the developed material is significantly hampered. At the same time, eukaryotic cells of animals grow and develop without hindrance. Thus, the material we have obtained can be used in photonics (photoconversion material for greenhouses, housings for LEDs), and it is also an affordable and non-toxic nanomaterial for creating antibacterial coatings.

Advanced Photonic Thin Films for Solar Irradiation Tuneability Oriented to Greenhouse Applications

The world population is growing by 1 billion people every 10 years. There will come a time when there will be more people to feed but less land to grow food. Greenhouses can be the solution to this problem because they provide the highest production yield per m² and also use less water, provide food safety, and offer high quality. Photosynthetic active radiation (PAR) favors vegetable growth with a specific blue and red light ratio. Thus, increasing the amount of red light improves chlorophyll absorption and photosynthetic efficiency. In this article, we present a hybrid system that combines luminescent materials and photonic crystals for better management of the light reaching the greenhouse. The luminescent dyes considered herein are combined ensuring a Förster resonance energy transfer (FRET) nonradiative mechanism to enhance the absorption range. The designed photonic crystal maximizes reflections in the Near-Infrared (NIR) range, and therefore, thermal losses are minimized. Thus, by converting harmful or ineffective radiation for plant growth to the PAR region, we aim to demonstrate growth-condition enhancement for the different vegetables that have been used as a model.