Reduced Light Intensity Research Articles

Effect of Different Light Intensities on the Quality of ‘Korla’ Fragrant Pear Fruits

This study aimed to investigate the effect of different light intensities on the quality of ‘Korla’ fragrant pear fruits. The differences in fruit quality were determined by evaluating the pigment content and fluorescent characteristics of the peel. The date of fruit weight, aspect ratio, soluble sugar content, soluble solid content, reducing sugar content, and vitamin C content of fruits, were higher under 100% light intensity than in shade treatment. However, firmness of the peel and pulp, and titratable acid content were enhanced in shade-treatment. Total chlorophyll, Chl a, and Chl b contents gradually decreased with the reduction in light intensity. The anthocyanin content gradually decreased with the decrease in light intensity. The maximum photochemical efficiency (FV/FM) of PSII significantly declined at 1% light intensity. As the light intensity decreased, the actual fluorescence quantum efficiency of PSII (F′V/F′M), non-photochemical quenching (NPQ), and actual photochemical efficiency of PSII (ΦPS II) progressively decreased. The results indicate that photoinhibition occurred in the peel of fragrant pear fruits. Shade treatment reduced the intrinsic quality of ‘Korla’ fragrant pear fruits, whereas a moderate decrease in light intensity could enhance the extrinsic quality of fruits.

Evaluation of selected rice cultivars' phenotypic traits and chlorophyll content under sub-mergence stress

Currently, rice production in Nigeria is on the increase with the aim of meeting the nation’s need but floods (mainly seasonal) has been among the major factors limiting rice production. Rice is generally a semi aquatic plant well adapted to partially flooded fields but flash flooding may leads to complete submergence there by resulting into huge economic losses mainly due to reduction in gases (hypoxia) and light intensity needed for photosynthesis. The research was conducted at the Biological Garden, Department of Biological Sciences, Federal University Birnin Kebbi. The experiment was set off in a Completely Randomized Design (CRD) consisting of four rice cultivars with control and three replications. Length of internodes, number of nodes per plant, plant height, root length and chlorophyll contents were evaluated using standard methods and protocols. The study analyzed the impact of flooding on rice cultivars, finding significant differences in node number, internode length, plant height, root lengths, and chlorophyll content. The highest number of nodes was found in CP Yartunga, followed by Faro with 6.33 per plant. The highest plant height was 15.50 cm in Faro, while the highest chlorophyll content was 0.41 mg/g in CP 44. The research reveals that rice cultivars recover from flooding stress, with CP Yartunga having the highest number of nodes per plant and Faro having the highest internode length. No significant differences were found in plant height, root length, or chlorophyll content among the evaluated cultivars. Faro had the lowest chlorophyll content. The study reveals that under stress, chlorophyll content in various locations decreases significantly, with a significant drop in recovery and node numbers. Lastly, node recovery is substantial, suggesting lower injury levels. The present study suggests that cultivars like Faro and CP 44 show better resilience, suggesting potential breeding programs focusing on structural traits.

Response of blueberry photosynthetic physiology to light intensity during different stages of fruit development.

To investigate the response of blueberry photosynthetic physiology to different light intensities during different stages of fruit development. In this study, four light intensity treatments (25%, 50%, 75% and 100% of full light) were set up to study the change rule of photosynthetic pigment content and photosynthetic characteristics of 'O'Neal' southern highbush blueberry leaves during the white fruiting stage (S1), purple fruiting stage (S2) and blue fruiting stage (S3) under different light intensity environments, and to explore the light demand and light adaptability of blueberry during different developmental stages of the fruit. The results showed that the chlorophyll and carotenoid contents of blueberry leaves showed an increasing trend with decreasing light intensity at all three stages of fruit development. The total chlorophyll content of blueberry leaves at 25% light intensity increased by 76.4% compared with CK during the blue fruiting stage; the maximum net photosynthetic rate (Pmax), light compensation point (LCP), light saturation point (LSP), rate of dark respirations (Rd), inter-cellular CO2 concentration (Ci), stomatal conductance (Gs), transpiration rate (Tr), net photosynthesis rate (Pn), and chlorophyll a/b showed a decreasing trend with decreasing light intensity. The Pn of blueberry leaves was highest under full light conditions at all three stages, and the Pn at 25% light intensity decreased by 68.5% compared with CK during the white fruiting stage Reflecting the fact that blueberries can adapt to low-light environments through increases in chlorophyll and carotenoids, but reduced light intensity significantly inhibited their photosynthesis. The photosynthetic physiology of blueberry showed a consistent pattern at all three stages, but there were some differences in the changes of photosynthetic parameters at different stages. The results of the study can provide theoretical references for the selection of sites and density regulation in blueberry production.

Identification and analysis of low light responsive yield enhancing QTLs in rice

Rice is one of the major food crops grown globally. However, during the wet season, rice suffers significant yield loss due to reduced light intensity caused by overcast clouds when the light intensity is only around 450–500 µmol/m2/s, compared to 1400–1800 µmol/m2/s in summer. This reduction in light intensity leads to a decrease in seed yield, mainly by limiting tiller or panicle numbers. Yield and its attributing parameters were recorded in one hundred thirty RILs for four consecutive wet seasons in ambient light (AL) and low light (LL, 35% light-cut using white shade net). QTL analysis was performed using Inclusive Composite Interval Mapping (ICIM) with all the phenotypic data and 927 polymorphic SNPs identified by the 7 K Infinium chip. The study identified a large QTL influencing panicle numbers and yield exclusively in lowlight on chromosome 1 (qPNLL1.1, qGYLL1.1) in four consecutive seasons with LOD > 10 and PVE > 30%. The favourable alleles are from the tolerant parent, Swarnaprabha. Another grain yield improving QTL was identified on chromosome 6 (qGYLL6.1), with LOD > 3 in three consecutive seasons. In a diverse rice panel of one hundred seventeen genotypes with five different models, association analysis identified the associated marker for panicle numbers and grain yield in LL, which is also the left marker of the newly identified QTLs for the traits under LL condition. A shade-responsive gene, monoculm 2 (MOC2, LOC_Os01g64660) inside the QTL on chromosome 1, upregulated in the tolerant parent and its QTL-carrying RILs, whereas repressed in the susceptible one. Therefore, due to its significant additive effect and validation across various genotypes, the yield-improving QTL on chromosome 1 can be directly utilised in marker-assisted selection (MAS) for developing shade-tolerant rice. This can also help reduce the yield gap between wet and dry-season rice.

Evaluating the Impact of Controlled Ultraviolet Light Intensities on the Growth of Kale Using IoT-Based Systems

Incorporating Internet of Things (IoT) technology into indoor kale cultivation holds significant promise for revolutionizing organic farming methodologies. While numerous studies have investigated the impact of environmental factors on kale growth in IoT-based smart agricultural systems, such as temperature, humidity, and nutrient levels, indoor ultraviolet (UV) LED light’s operational efficiencies and advantages in organic farming still need to be explored. This study assessed the efficacy of 15 UV light-controlling indoor experiments in three distinct lighting groups: kale cultivated using conventional household LED lights, kale cultivated using specialized indoor UV lights designed for plant cultivation, and kale cultivated using hybrid household and LED grow lights. The real-time IoT-based monitoring of light, soil, humidity, and air conditions, as well as automated irrigation using a water droplet system, was employed throughout the experiment. The experimental setup for air conditioning maintained temperatures at a constant 26 degrees Celsius over the 45-day study period. The results revealed that a combination of daylight household lights and indoor 4000 K grow lights scored the highest, indicating optimal growth conditions. The second group exposed to warm white household and indoor grow red light exhibited slightly lower scores but larger leaf size than the third group grown under indoor grow red light, likely attributable to reduced light intensity or suboptimal nutrient levels. This study highlights the potential of indoor UV LED light farming to address challenges posed by urbanization and climate change, thereby contributing to efforts to mitigate agricultural carbon emissions and enhance food security in urban environments. This research contributes to positioning kale as a sustainable organic superfood by optimizing kale cultivation.

Disease Incidence of Bacterial Pustules (Xanthomonas axonopodis pv. glycines) on Some Soybean Varieties Planted in Mahogany Agroforestry System in Alas Bromo Forestry

Abstract Soybean production in Indonesia needs to supply for domestic needs sufficiently. One of the things that influence is the reduction of soybean harvest areas in Indonesia. One of the solutions to the problem is through extensification by utilizing land under shade, which is called an agroforestry system. Agroforestry systems will change intercrop environmental conditions such as reducing light intensity, temperature and increasing humidity. The condition will affect disease development in soybean plants, especially bacterial pustule disease caused by Xanthomonas axonopodis pv. Glycines. X. axonopodis bacteria can reduce soybean productivity by up to 57.61% in susceptible hosts and favorable environmental conditions. In this research, observations were made regarding the symptoms and incidence of bacterial pustules infection on seven varieties under the shade of mahogany. The varieties used were Anjasmoro, Argomulyo, Dena-1, Dena-2, Denasa-1, Denasa-2, and Devon-1. The research was conducted for three months at KHDTK (Kawasan Hutan dengan Tujuan Khusus) Alas Bromo, Karanganyar, Central Java, Indonesia. The research showed that the lowest incidence of bacterial pustule occurred in the Anjasmoro varieties, with an incidence value of 0%. In comparison, the highest incidence of attacks occurred on the Denasa-1 variety, up to 23.3%.

Caloric restriction extends lifespan in a clonal plant.

When subjected to dietary caloric restriction (CR), individual animals often outlive well-fed conspecifics. Here, we address whether CR also extends lifespan in plants. Whereas caloric intake in animals comes from ingestion, in plants it derives from photosynthesis. Thus, factors that reduce photosynthesis, such as reduced light intensity, can induce CR. In two lab experiments investigating the aquatic macrophyte Lemna minor, we tracked hundreds of individuals longitudinally, with light intensity-and hence, CR-manipulated using neutral-density filters. In both experiments, CR dramatically increased lifespan through a process of temporal scaling. Moreover, the magnitude of lifespan extension accorded with the assumptions that (a) light intensity positively relates to photosynthesis following Michaelis-Menten kinetics, and (b) photosynthesis negatively relates to lifespan via a power law. Our results emphasize that CR-mediated lifespan extension applies to autotrophs as well as heterotrophs, and suggest that variation in light intensity has quantitatively predictable effects on plant aging trajectories.

Calibration of absorption coefficients of liquid solutions for measuring liquid film thickness by absorptiometry

Abstract Infrared absorptiometry is a widely used non-intrusive method for measuring the thickness of liquid films. The accuracy of that measurement depends crucially on having high-accuracy data of the absorption coefficient of the laser light used, which is, however, not easily available, especially for the wavelength range where the absorption is strong. Here we propose a method to calibrate the absorption coefficients in such cases. By measuring the light intensity reduction while scanning through a liquid film formed in a wedge, whose angle can be adjusted and determined a priori from interferometry, the absorption coefficient of the liquid can be accurately obtained without the need to create a flat liquid film with exact known thickness. The method is verified by calibrating the absorption coefficient of pure water at an infrared wavelength and the result agrees very well with the values found in the literature. As a demonstration of the application of the method, the absorption coefficients of soap solutions with different compositions were calibrated and used to measure the thicknesses of draining soap films. The results from the absorptiometry are in good agreement with the film thickness measured simultaneously from interferometry.

Seasonal patterns of phytoplankton photoacclimation in a dimictic oligotrophic lake over 5 yr: Implications for chlorophyll as an estimate of biomass

AbstractChlorophyll a is commonly used as a surrogate for algal biomass in lakes and oceans even though phytoplankton can readily adjust intracellular chlorophyll concentration to changes in the environment through a cellular process termed photoacclimation. Marine studies have documented fluctuations in cellular chlorophyll to year‐round changes in light intensity and nutrients using the chlorophyll : carbon ratio to estimate cellular pigment density. However, similar freshwater studies are almost exclusively limited to chlorophyll : carbon ratios at the summertime deep chlorophyll maximum (DCM) depth in less productive water. This study expands direct estimates of freshwater photoacclimation to all seasons of the year utilizing optically derived estimates of algal carbon and chlorophyll fluorescence from high‐frequency (daily) data. We describe patterns of photoacclimation at daily, seasonal, and interannual time scales over a 5‐yr period. We show that increases in chlorophyll density at the cellular level not only occurred at the DCM depth during summer stratification but were a dominant and recurring feature when the lake was vertically mixing in fall, winter, and spring. Pigment density within the mixed layer was negatively correlated with light level, indicating a photoacclimation driven response to reduced light intensity. Predicting how cellular pigment density is affected by the surrounding environment in a replicated range of lake systems is needed if chlorophyll is to be accurately used as an estimate of algal biomass in freshwaters.

Light quality induces a shift in coccosphere morphology in Scyphosphaera apsteinii.

The coccolithophore Schyphosphaera apsteinii produces distinct coccolith morphotypes and offers a unique insight into coccolith calcification, as the number of lopadoliths per cell increases under low light intensities. This study employs S. apsteinii to investigate the acclimated impact of light intensity and wavelength on cell physiology and coccosphere morphology. Our findings reveal a marked increase in lopadolith production when grown under reduced light intensity, with lower growth rates, higher chlorophyll concentration and elevated net photosynthetic rates. Reduced blue-light also caused an increase in lopadolith numbers, elevated chlorophyll concentrations and net photosynthetic rates. Conversely, such responses are less pronounced under reduced red-light. Moreover, reduced blue- and red-light treatments exhibited enhanced growth rates compared to the light-replete control, despite a reduction in light intensity. Our findings suggest that changes in light quality cause a shift in the coccosphere morphology, affecting cell physiology and potentially aiding light harvesting in S. apsteinii.

Genome-wide identification of GATA transcription factor family and the effect of different light quality on the accumulation of terpenoid indole alkaloids in Uncaria rhynchophylla.

Uncaria rhynchophylla is an evergreen vine plant, belonging to the Rubiaceae family, that is rich in terpenoid indole alkaloids (TIAs) that have therapeutic effects on hypertension and Alzheimer's disease. GATA transcription factors (TF) are a class of transcription regulators that participate in the light response regulation, chlorophyll synthesis, and metabolism, with the capability to bind to GATA cis-acting elements in the promoter region of target genes. Currently the charactertics of GATA TFs in U. rhynchophylla and how different light qualities affect the expression of GATA and key enzyme genes, thereby affecting the changes in U. rhynchophylla alkaloids have not been investigated. In this study, 25 UrGATA genes belonging to four subgroups were identified based on genome-wide analysis. Intraspecific collinearity analysis revealed that only segmental duplications were identified among the UrGATA gene family. Collinearity analysis of GATA genes between U. rhynchophylla and four representative plant species, Arabidopsis thaliana, Oryza sativa, Coffea Canephora, and Catharanthus roseus was also performed. U. rhynchophylla seedlings grown in either red lights or under reduced light intensity had altered TIAs content after 21 days. Gene expression analysis reveal a complex pattern of expression from the 25 UrGATA genes as well as a number of key TIA enzyme genes. UrGATA7 and UrGATA8 were found to have similar expression profiles to key enzyme TIA genes in response to altered light treatments, implying that they may be involved in the regulation TIA content. In this research, we comprehensively analyzed the UrGATA TFs, and offered insight into the involvement of UrGATA TFs from U. rhynchophylla in TIAs biosynthesis.

Impact of low light intensity on biomass partitioning and genetic diversity in a chickpea mapping population.

With recent climatic changes, the reduced access to solar radiation has become an emerging threat to chickpeas' drought tolerance capacity under rainfed conditions. This study was conducted to assess, and understand the effects of reduced light intensity and quality on plant morphology, root development, and identifying resistant sources from a Sonali/PBA Slasher mapping population. We evaluated 180 genotypes, including recombinant inbred lines (RILs), parents, and commercial checks, using a split-block design with natural and low light treatments. Low light conditions, created by covering one of the two benches inside two growth chambers with a mosquito net, reduced natural light availability by approximately 70%. Light measurements encompassed photosynthetic photon flux density, as well as red, and far-red light readings taken at various stages of the experiment. The data, collected from plumule emergence to anthesis initiation, encompassed various indices relevant to root, shoot, and carbon gain (biomass). Statistical analysis examined variance, treatment effects, heritability, correlations, and principal components (PCs). Results demonstrated significant reductions in root biomass, shoot biomass, root/shoot ratio, and plant total dry biomass under suboptimal light conditions by 52.8%, 28.2%, 36.3%, and 38.4%, respectively. Plants also exhibited delayed progress, taking 9.2% longer to produce their first floral buds, and 19.2% longer to commence anthesis, accompanied by a 33.4% increase in internodal lengths. A significant genotype-by-environment interaction highlighted differing genotypic responses, particularly in traits with high heritability (> 77.0%), such as days to anthesis, days to first floral bud, plant height, and nodes per plant. These traits showed significant associations with drought tolerance indicators, like root, shoot, and plant total dry biomass. Genetic diversity, as depicted in a genotype-by-trait biplot, revealed contributions to PC1 and PC2 coefficients, allowing discrimination of low-light-tolerant RILs, such as 1_52, 1_73, 1_64, 1_245, 1_103, 1_248, and 1_269, with valuable variations in traits of interest. These RILs could be used to breed desirable chickpea cultivars for sustainable production under water-limited conditions. This study concludes that low light stress disrupts the balance between root and shoot morphology, diverting photosynthates to vegetative structures at the expense of root development. Our findings contribute to a better understanding of biomass partitioning under limited-light conditions, and inform breeding strategies for improved drought tolerance in chickpeas.

Light-driven thermocatalytic CO2 reduction by CH4 on alumina-cluster-modified Ni nanoparticles with excellent durability and high light-to-fuel efficiency promoted by the photoactivation effect

Using inexhaustible solar energy to drive efficient light-driven thermocatalytic CO2 reduction by CH4 (DRM) is an attractive approach that can synchronously reduce the greenhouse effect and convert solar energy into fuels. However, it is often limited by the intense light intensity required to produce high fuel production rates, and the catalyst deactivation due to severe carbon deposition generated from side reactions. Herein, a nanostructure of alumina-cluster-modified Ni nanoparticles supported on Al2O3 nanorods (ACM-Ni/Al2O3) was synthesized, displaying good catalytic performance under focused UV–vis-IR illumination. By light-driven thermocatalytic DRM on ACM-Ni/Al2O3 at a reduced light intensity of 76.9 kW m−2, the high fuel production rates of H2 (rH2, 65.7 mmol g−1 min−1) and CO (rCO, 78.8 mmol g−1 min−1), as well as an efficient light-to-fuel efficiency (η, 26.3 %) are achieved without additional heating. The rH2 and rCO of light-driven thermocatalysis are 2.9 and 1.9 times higher, respectively, compared to conventional thermocatalysis at the same temperature. We have discovered that high light-driven thermocatalytic activity originates from the photoactivation effect, significantly reducing the apparent activation energy and facilitating C* oxidation as a decisive step in DRM. ACM-Ni/Al2O3 possesses excellent durability and exhibits an extremely low coking rate of 4.40 × 10−3 gc gcatalyst−1 h−1, which is 26.8 times lower than that of the reference sample without Al2O3 cluster modification (R-Ni/Al2O3). This is owing to a decrease in activation energies (Ea) of C* oxidation and an increase in Ea of C* polymerization by the surface modification of Ni nanoparticles with Al2O3 clusters, effectively inhibiting carbon deposition.

Analysis of Characteristics in the Macro-Composition and Volatile Compounds of Understory Xiaobai White Tea.

Understory planting affects the growth environment of tea plants, regulating the tea plant growth and the formation of secondary metabolites, which in turn affects the flavor of Xiaobai white tea. The present research adopted biochemical composition determination, widely targeted volatilities (WTV) analysis, multivariate statistical analysis, and odor activity value (OAV) analysis to analyze the characteristics in the macro-composition and volatile compounds of understory white tea. The sensory evaluation results indicated that understory Xiaobai white tea (LWTs) was stronger than ordinary Xiaobai white tea (PWTs) in terms of the taste of smoothness, sweetness, and thickness as well as the aromas of the flower and sweet. Understory planting reduced light intensity and air temperature, increased air humidity, organic matter, total nitrogen, and available nitrogen contents, which improved the growth environment of tea plants. The phytochemical analysis showed that the water-extractable substances, caffeine, flavonoids, and soluble sugar contents of understory tea fresh-leaf (LF) were higher than those of ordinary fresh-leaf (PF). The phytochemical analysis showed that the free amino acids, theaflavins, thearubigins, water-extractable substances, and tea polyphenols contents of LWTs were significantly higher than those of PWTs, which may explain the higher smoothness, sweetness, and thickness scores of LWTs than those of PWTs. The 2-heptanol, 2-decane, damasone, and cedar alcohol contents were significantly higher in LWTs than in PWTs, which may result in stronger flowery and sweet aromas in LWTs than in PWTs. These results provide a firm experimental basis for the observed differences in the flavor of LWTs and PWTs.

Reduced snow and increased nutrients show enhanced ice‐associated photoautotrophic growth using a modified experimental under‐ice design

AbstractUnder‐ice photoautotrophs in lakes are generally considered to be limited by light rather than nutrients. Despite reduced light intensity under the ice, there is increasing evidence that suggests some lakes support high levels of photoautotrophs. We explored how snow cover (i.e., light) and nutrients (i.e., nitrogen and phosphorus) influence ice‐associated photoautotroph growth in a Minnesota, USA lake. Using a novel under‐ice approach, we deployed nutrient diffusing substrates (single or combined nutrient amendments) under two different light scenarios (snow covered, reduced light; snow removed, increased light) near the water‐ice interface to mimic a range of conditions ice‐associated photoautotrophs may be exposed to. Natural snow cover reduced light compared with snow removal, particularly early in the experiment before snow began to melt. When comparing photoautotroph chlorophyll a (Chl a) between snow treatments, we found a significant snow effect with higher concentrations in the snow removed treatment. We also found a significant nutrient effect, for all nutrient treatments, on Chl a concentrations in both snow conditions. The effect of any nutrient treatment on Chl a concentrations was similar. Our results suggest that ice‐associated photoautotrophs were able to grow in all snow conditions, but snow removal resulted in higher growth and nutrient availability also mediated responses. Thus, both light and nutrient conditions in the winter may strongly affect ice‐associated photoautotroph dynamics.

Capture of wild juveniles, growth and spawning of the southwestern Atlantic wreckfish (Polyprion americanus) in Argentina

Wreckfish (Polyprion americanus) is a marine fish of great interest as a new aquaculture species due to its easy adaptation to farming conditions, rapid growth and market price. In the Southwestern Atlantic Ocean, the species forms a genetic stock different from that of the Northern Hemisphere and also to populations of the South Pacific. This study presents the research conducted in Argentina from 2011 to 2020 on the development of a wreckfish broodstock from juvenile specimens. Wreckfish (n = 21) were caught with fishing rods at depth between 18 and 75 m depth, off the coast of Buenos Aires Province, Argentina (37°30′S - 39°00′S). All fish suffered barotrauma, but specimens captured at a depth < 45 m and whose swim bladders were deflated by puncture had a survival rate > 90%. Juvenile wreckfish (n = 12) with an initial body weight of 2–3 kg were kept in a recirculating aquaculture system (RAS) and fed local fish for 36 months. During this on-growing stage, a natural photoperiod regime with reduced light intensity was accompanied by seasonal variations in the RAS's thermal regime (14–19 °C). From then on, a maturity and reproductive protocol was implemented, where the temperature was lowered (12–17 °C) and the diet was complemented with a formulated semi-moist feed. Juvenile wreckfish grew fast, gaining about 2.5 kg in 11 months with a specific growth rate (SGRBW) of 0.2% day−1 and reaching 10–12 kg in 36 months. There was no significant difference in growth performance between sex groups during the on-growing stage. However, from months 36 to 57, the SGRBW of females (0.058 ± 0.008% day−1) was significantly higher than males (0.035 ± 0.005% day−1). After 67 months in captivity, the first natural spawning was achieved in a communal tank with a sex ratio 4 females: 6 males. Two consecutive spawning seasons were analysed, which showed a large daily variation in total number of eggs, percentage of floating eggs (potentially viable eggs) and spawning intervals. A marked improvement in spawning performance was observed from one season to the next. In the first season, a total production of 5.21 million eggs was reached, of which only about 2.7% were floating, while in the second season the values increased to 13.23 million eggs and 32.6%, respectively. We have successfully developed a broodstock of wreckfish capable of achieving natural spawning. Further research is needed to obtain reliable spawning and large production of high-quality eggs.

Comparison of the Stand Structure Diversity of Open Pinus brutia Ten. Forests in Areas of Different Productivity in Central Cyprus

The goal of this study is to compare the diversity of the stand structure of open P. brutia forests in areas of different productivity at middle elevations in central Cyprus. This will help us figure out how much biodiversity they can hold. Two plots of 4 ha were randomly established. One 200 m × 200 m square-shaped plot was established in a P. brutia formation in a medium productivity site, and one in a P. brutia formation in a bad productivity site. In each plot, dendrometrical data were recorded. In total, 160 hemispherical photographs were taken on both plots. The stand structure is more heterogeneous and complex at medium productivity sites compared to bad productivity sites. P. brutia formations in medium productivity sites can support greater biodiversity than the corresponding formations in bad productivity sites. In the open P. brutia formations of central Cyprus, forest practice must aim to increase the density of P. brutia trees in some tree groups to reduce light intensity under the group canopy. Moreover, trees with large diameters and/or heights must be protected from disturbances. This approach will increase the ability of formations to support biodiversity.

Effects of light intensity and reduction of starter diet digestible lysine and metabolizable energy on broiler chicken growth performance, breast meat yield, and meat quality defects

The etiology of Wooden Breast (WB) is unknown; therefore, it is difficult to produce broiler flocks with similar proportions of WB-affected and unaffected birds. Because WB has been detected as early as 15 d posthatch, the objective of this randomized complete block experiment with a 2×2 factorial treatment arrangement was to determine whether combining the effects of light intensity (LI) and early nutrient reduction strategies could reliably produce WB-affected and normal broilers to further investigate the physiological mechanisms underlying WB. On day of hatch, male, Ross 708×Yield Plus broilers (n=384; 16 birds per pen; 3 replicate blocks) were randomly allotted to floor pens in the same facility and exposed to either 2 (LOWLI) or 30 (HIGHLI) lux of light from d 0 to 35. Birds were fed either a commercial starter diet (CON) or the CON diet with a 10% reduction in both ME and digestible lysine (dLys; RED) from d 0 to 14 and then a common grower diet from d 15 to 35. Broiler growth performance, breast yield, and incidence and severity of WB and White Striping (WS) were assessed. Data were analyzed as a 2-way ANOVA with SAS PROC GLIMMIX and means separated at P < 0.05 with PDIFF. No interaction among LI and diet was observed (P > 0.05). Broilers reared with HIGHLI were heavier on d 35 and consumed more feed in all phases compared with broilers reared under LOWLI (P ≤ 0.0096). Broilers reared under LOWLI gained less BW from d 15 to 35 and d 0 to 35 compared with broilers reared under HIGHLI (P=0.0073). Broilers fed the RED starter diet consumed more feed and had higher FCR from d 0 to 14 compared with broilers fed the CON diet (P ≤ 0.0012). In conclusion, combining reductions in LI and starter diet ME and dLys did not produce the hypothesized reductions in breast yield and incidence and severity of WB or WS.

Optimizing Light Use Efficiency and Quality of Indoor Organically Grown Leafy Greens by Using Different Lighting Strategies

Vertical farming is experiencing significant growth, and the optimization of artificial lighting is essential for enhancing the sustainability of this growing system. Therefore, the aim of this study was to examine how light segmentation, the incorporation of a low-intensity lighting phase known as the light compensation point (LCP) instead of the traditional dark phase, and variations in the light spectrum impact the agricultural outcomes of organically cultivated leafy greens. In controlled growth chamber environments, a variety of leafy plant species (Spinacia oleracea L., Ocimum basilicum, Beta vulgaris L., Lactuca sativa L. cv. ‘Garrison’ and ‘Blade’, Brassica rapa cv. ‘Japonica’ and ‘Chinensis’, Brassica juncea cv. ‘Scarlet Frills’ and ‘Wasabina’, Eruca sativa and Perilla frutescens L.) were subjected to four light treatments with varying intensities and durations of lighting, while in a second experiment, five different spectral growing conditions were compared. Irrespective of the plant species, shortening the length of the diel cycle by extending the cumulative daily lighting to 20–24 h per day (5L/1N [5 h at 261 µmol m−2 s−1 + 1 h darkness for a total of 20 h of light per day] and 5L/1LCP [5 h at 256 µmol m−2 s−1 + 1 h LCP at 20 µmol m−2 s−1 for a total of 24 h of light per day]) led to an average increase of +12% in height, fresh weight (+16%), dry weight (+23%), and specific leaf weight (+11%), compared to the control plants (18L/6N; 18 h at 289 µmol m−2 s−1 + 6 h darkness) and 6L/6LCP plants (6 h at 418 µmol m−2 s−1 + 6 h LCP at 20 µmol m−2 s−1 for a total of 24 h of light per day) during the first harvest. This also resulted in better light utilization, expressed as increased fresh (+16%) and dry (+24%) biomass per mol of light received. Conversely, the studied light spectral treatments had no effect on the growth parameters of the four selected species. In conclusion, our study showed that reducing light intensity while extending the photoperiod could potentially represent a cost-effective LED strategy for the indoor cultivation of organically or conventionally grown leafy greens.

Ternary alloyed BaxCd1−xS nanocrystals: Synthesis, bandgap tuning, and photovoltaic performance

This work reports the synthesis and photovoltaic properties of a new semiconductor–ternary alloyed BaxCd1−xS nanocrystals, prepared by replacing a fraction of the Cd2+ ions in the host CdS with Ba2+ ions (x = 0−0.13) using the sequential ionic layer adsorption and reaction. Optical measurements revealed a decreasing bandgap in BaxCd1−xS from 2.24 to 2.14 eV with increasing x, increasing the optical absorption range from 300 to 553 nm in CdS to 300−579 nm in BaxCd1−xS. Liquid-junction semiconductor quantum dot-sensitized solar cells (QDSSCs) were fabricated from BaxCd1−xS nanocrystals using polysulfide electrolyte and CuS counter electrode. The Ba0.09Cd0.91S QDSSC (x = 0.09) yielded the best power conversion efficiency (PCE) of 3.95% under 1 sun, which is 33% higher than that (2.96%) of the host CdS. A ZnS passivation layer treatment on the best Ba0.09Cd0.91S sample increased the PCE to 4.57% (JSC = 9.33 mA/cm2, Voc = 0.80 V, fill factor = 61.2%) under one sun. The PCE further increased to 5.21% under a reduced light intensity of 0.1 sun. This work demonstrates the potential of tunable optoelectronic properties in BaxCd1−xS by controlling the Ba content and enhancing the photovoltaic performance by increasing the absorption range.