Shades Of Blue Research Articles

DEVELOPMENT OF A PAPER-BASED DEVICE USING INDOXYL ACETATE AS A CHROMOGENIC SUBSTRATE FOR RAPID QUALITATIVE DETERMINATION OF LIPASE INHIBITOR

An improved paper-based device using indoxyl acetate as a chromogenic substrate was developed for rapid qualitative determination of lipase inhibitory activity. Colorless indoxyl acetate can be catalytically hydrolyzed by lipase to produce the blue-colored indigo dimer on the paper device. In the presence of a lipase inhibitor, enzyme activity diminishes, resulting in reduced hydrolysis of indoxyl acetate. Consequently, this leads to a decrease in the intensity of the blue coloration, which can be visually observed across a range of blue shades and analyzed using image analysis. Orlistat was used as the representative lipase inhibitor in the assay. The LODs obtained from visual detection and the image analysis were comparable. The paper-based device using indoxyl acetate for lipase inhibition assay was simple and convenient. It could be useful as a simple screening method for the detection of orlistat adulteration in weight loss supplements.

Abundance of microplastics in the agro-industrial product beet sugar; food or plastifood

Recently, microplastic contamination in various foodstuffs ranging from natural aquatic products to industrial products has begun to be revealed. While actual exposure data are needed in food safety and health to demonstrate the potential risks and effects of microplastics (MPs), this information is still limited for most foods. Foods such as table sugar, which are produced by processing in many industrial processes as well as being an agricultural product, are susceptible to MP contamination during the processing and packaging stages. This study aims to draw attention to the sources of MP contamination in agro-industrial products and reveal the risks of exposure through sugar consumption, with specific investigations into table sugar. For this purpose, 19 store-bought sugars (beet) of different types (crystal, cube and powdered) were analyzed. Optical microscope, Nil red staining-fluorescence microscope, SEM (Scanning Electron microscope) and ATR-FT-IR (Attenuated Total Reflection (ATR)-Fourier transform infrared (FT-IR)) analyzes were performed on the samples taken on the filter after peroxide treatment and filtration processes. Average 29110 MPs/100 g was detected in sugars and the most common MP type was in fragment form. Various polymer structures such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyester (PES), polyamide (PA), polystyrene (PS), polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), acrylic derivatives, additives, pigments, and paints were detected. The most detected MP color in sugars containing a colorful MP cocktail is black (29.2%). This is followed by blue shades, white-transparent, red, yellow-orange and others. Microplastic intake rates from crystal sugars are 857 particles/capita/day and 196 particles/capita/day for children and adults, respectively. Microplastic contamination factor (MPCF) values demonstrate a very high level of contamination of sugars with MPs. The prioritization assessment for sources of MPs in sugars indicates that production processes can be a significant source of pollution.

Mapping of Vegetation and Environmental Conditions

There are various methods of vegetation mapping which depend upon the scale of the work and the facts to be shown. Professor H. GAUSSEN’s method has proved as successful in Tropical India as in temperate and mediterranean regions. It aims at representing the vegetation types at medium and small scales.(1) The basic principle is the use of colours of an ecological value. Among the factors of the environment, only those which play a part in the water equilibrium of the vegetation will be shown and the combination of their colours will become representative of the ecology.High temperature and long dry period will increase the evaporation. Rainfall and relative humidity 'will be favourable to the plant growth. Then a conventional, but natural choice of blue and violet shades for humidity, and on the other hand, red or yellow shades for heat and drought will provide all the coloration possibilities.Six classes are defined for Temperature, Rainfall and Xerothermic index (length and intensity of the dry season). Each class has its conventional shade. In any place the climate is easily summarised into an ecological formula which will include for more precision the light factor, the vegetative period and the soil factor.Soil factor is taken into account:-either by its effect on the water balance. The colour is shaded accordingly, for instance, the mangrove, the vegetation of saline soils ;-or by its limiting effect on the floristic composition of the vegetation types. For example, the lateritic caps. These features are shown by the superimposition of a symbol.(2) Another originality of the method is the representation of "Series.of Vegetation". Various physiognomic stages of degradation of the same series are shown by means of lines, stripplings etc. But the same colour, representative of the general ecology of one series is used for all its serial stages.Floristic releves are made in the field. Their comparison brings out the relationship between the successive stages of the series and leads to the most developed type possible under the present ecological conditions. This maximum stage, the least disturbed by biotic factors, is the "plesioclimax". It is the maximum vegetation to be expected under present conditions if human interference it excluded. Its characteristic and dominant species axe used to name the series.The plesioclimax helps to appreciate the ecological-potentiality of the place and therefore will be of some guidance for the introduction of new species.Since similar colours are used for similar climates in the world, the colours show homo-bioclimates under which grow similar vegetation, types even if their floristic composition is different.Several examples are taken from vegetation maps of Tunisia, Algeria, and South India.

On the issue of the manufacture of ceramic structures in orthopedic dentistry

The article presents a review of ceramic materials used in modern orthopedic dentistry. Currently, the main types of orthopedic structures containing dental porcelain are metal-ceramic, metal-free ceramic crowns, as well as prostheses made using pressed ceramic technology, in particular veneers. All types of prostheses produced using dental porcelain have a common manufacturing technology, which consists in the sequential application of ceramic layers with their subsequent firing. Moreover, for each group of teeth, there are additional masses for firing, for example, masses of the cutting edge, masses simulating various effects (for example, blue, yellow and other shades, imitation of tooth growth lines). These masses are created in order to give future crowns the most natural and aesthetic appearance. All structural components (layers) of ceramics used in the manufacture of ceramic prostheses have a similar chemical composition. The raw material is feldspar glass with inclusions of crystalline quartz. Depending on the conditions of the reactions, the composition of mixtures can be varied and compounds with desired properties can be obtained using the phase analysis method, which will expand the range of domestic ceramic materials produced, which are currently quite scarce. This is especially relevant in modern conditions of import substitution.

Understanding color variation with site distribution in inverse spinel structure via neutron diffraction, magnetism, and optical studies

Chromophores at different coordinations can give rise to different colors; usually, chromophores at non-centrosymmetric coordinations are preferred for intense pigments. Different solid solutions M2-xCoxM’O4 (M = Mg/Zn, and M’ = Ti/Sn) with inverse spinel structure were synthesized with the goal of understanding color variation with site distribution, as the chromophore Co2+ in these solid solutions can occupy either the tetrahedral or octahedral sites or both depending on the composition. Another goal was to develop environmentally friendly and cheap blue pigments by reducing the carcinogenic cobalt to obtain a similar color to that of commercially available cobalt blue, which uses a significant amount of Co2+ (33.31 % by mass). For Mg2-xCoxTiO4 series, turquoise blue hues were observed for low cobalt content, and different shades of blue were observed for Mg2-xCoxSnO4 series with a color similar to cobalt blue, including just 4.90% of cobalt by mass. While for Zn2-xCoxTiO4, and Zn2-xCoxSnO4 series, different shades of brown and different shades of green, respectively, were observed. One of the main reasons behind the major difference in color for the Mg and Zn containing solid solutions, regardless of the same chromophore in the same structure is related to the chromophore site distribution in the system. For the Mg-containing solid solutions, different shades of blue are observed as Mg has no preference for any of the sites, Co2+ mostly goes to tetrahedral sites. In contrast, for the Zn-containing solid solutions, no blue shades were observed because of the strong preference of Zn for the tetrahedral sites owing to the sp3 hybridization, which in turn forces Co2+ to occupy the octahedral sites. Neutron refinement proves that Co2+ occupies mainly tetrahedral sites in the Mg-containing solid solutions and mostly octahedral sites in the Zn-containing solid solutions.

Synthesis, some Physicochemical and Biomedical Properties of colored Apatite‐Structured Compounds with Mn5+ and Cr5+

AbstractDevelopment of new non‐toxic pigments of a wide range of applications (from coloring of bone cements to aesthetic cosmetology, including tattooing) of blue and green shades is an urgent task. In the present work, colored compounds with apatite structure were synthesized by solid‐phase method. The obtained products were crystallized in hexagonal syngony of P63/m space group. The alloying elements – chromophores Mn5+ and Cr5+ in tetrahedrally coordinated positions – were responsible for sky‐blue and turquoise colors of the compounds, respectively. The conducted complex study (crystal structure, IR spectroscopy, color measurements, diffuse reflectance spectroscopy, electron paramagnetic resonance, cytotoxicity, surface morphology) of the colored compounds opens new opportunities for the development of alternative pigments of similar color range and expansion of the field of application of pigments based on compounds of apatite structural type. The results of in vitro study of cytotoxicity demonstrated the potential suitability of sky‐blue color compound (Mn‐containing apatite) for further creation of cold pigments on its basis for tattoo ink and bone cement coloring.

Blue-Green Horizons: Redefining Alginate Bioplastics with Spirulina Dyes

AbstractThis study introduces a novel, eco-friendly approach for the extraction and application of Spirulina (Sp.) pigments in alginate bioplastics, representing a significant advancement over traditional dyeing methods. The research explores a zero waste model process in a Fab Lab setting, involving three stages, liquid dye preparation, fibre dyeing, and bioplastic dyeing, with a focus on utilizing all by-products sustainably. In the liquid dye preparation phase, vibrant blue-green pigments were successfully extracted from Spirulina powder. The colour depth depended on the Spirulina concentration and the precipitation method used, with pH playing a critical role in achieving a range of green–blue hues. The fibre dyeing phase tested Spirulina dyes on various natural fibres, examining the impact of alum mordant pre-treatment on colour absorption and stability. Optimal dyeing results were obtained with a 1:1 ratio of Spirulina-filtered powder suspension to alum acid precipitation solution at a pH of 4. The techniques optimized were then applied to alginate bioplastics, including bio-yarns and bio-films, yielding a wide spectrum from green to blue. Bio-yarns showed better colour retention compared to bio-films, possibly due to residual alum. However, challenges in long-term colour stability and structural integrity against environmental factors like oxidation and humidity were observed. The study contributes valuable insights into the application of natural dyes in bioplastics, particularly in achieving blue and green shades with a Spirulina zero waste model. This work is significant for future sustainable material science research and emphasizes the importance of balancing aesthetic, functional, and environmental factors in circular design. Graphical Abstract

Color vision of people with headaches

The aim of the study is to obtain new data on possible changes in color vision of people with headaches. The object of the study is people who periodically experience primary headaches of different nature. The subject of the study is the specificity of perception of chromatic parameters of the environment and color sensitivity of people with headaches of different nature, quality, intensity and frequency. The data were collected using the Farnsworth-Munsell standard clinical color vision test (FM-100). The study involved 65 people aged 17 to 66 years. The results of the assessment of color vision in the experimental group were compared with the normative indicators and data obtained in the age-matched control group (N=40). Special attention was paid to discussing the possible causes of the identified disorders and analyzing the correlation between various aspects of headache with individual indicators of color sensitivity. The data analysis included calculating the total error (TES), as well as partial errors (PES) along the blue-yellow (B-Y) and red-green (R-G) axes. We also identified partial errors for individual tones. The study revealed a noticeable specificity in the perception of blue-green and blue shades of patients with severe, chronic and non-localized headaches. Since the detected color vision disorders appear to be temporary and are most likely typical of the premonitory phase of headaches, the results of this study may contribute to understanding of headache predictors. Since the identified changes relate to only one group of (blue) shades, the findings of the study can be used in the development of alternative treatment methods. In particular, in choosing the optimal color of tinted lenses, which are offered to patients to relieve headaches and reduce their frequency.

Metal-free production of natural blue colorants through anthocyanin–protein interactions

IntroductionThe scarcity of naturally available sources for blue colorants has driven reliance on synthetic alternatives. Nevertheless, growing health concerns have prompted the development of naturally derived blue colorants, which remains challenging with limited success thus far. Anthocyanins (ACNs) are known for providing blue colors in plants, and metal complexation with acylated ACNs remains the primary strategy to generate stable blue hues. However, this approach can be costly and raise concerns regarding potential metal consumption risks. ObjectivesOur study aims to introduce a metal-free approach to achieve blue coloration in commonly distributed non-acylated 3-glucoside ACNs by exploring their interactions with proteins and unveiling the underlying mechanisms. MethodsUsing human serum albumin (HSA) as a model protein, we investigated the structural influences of ACNs on their blue color generation using visible absorption spectroscopy, fluorescence quenching, and molecular simulations. Additionally, we examined the bluing effects of six proteins derived from milk and egg and identified the remarkable roles of bovine serum albumin (BSA) and lysozyme (LYS). ResultsOur findings highlighted the importance of two or more hydroxyl or methoxyl substituents in the B-ring of ACNs for generating blue colors. Cyanidin-, delphinidin- and petunidin-3-glucoside, featuring two neighboring hydroxyl groups in the B-ring, exhibited blue coloration when interacting with HSA or LYS, driven primarily by favorable enthalpy changes. In contrast, malvidin-3-glucoside, with two methoxyl substituents, achieved blue coloration through interactions with HSA or BSA, where entropy change played significant roles. ConclusionOur work, for the first time, demonstrates the remarkable capability of widely distributed 3-glucoside ACNs to generate diverse blue shades through interactions with certain proteins. This offers a promising and straightforward strategy for the production of ACN-based blue colorants, stimulating further research in this field.

Evaluating the Color Matching Ability of a Smart Chromatic Technology-Based Composite Resin for Premolar Teeth Restoration.

Objectives: This study aims to evaluate the color-matching ability of OMNICHROMA composite, a single-shade composite, using the CIE L ∗ a ∗ b ∗ system and determining ΔE values. Materials and Methods: In this in vitro study, 30 intact premolar teeth were collected, cleaned, and disinfected with 0.5% thymol solution. The teeth were stored in distilled water at 37°C. A putty index calibrated the color assessment sites on buccal and lingual surfaces. Two cavities were prepared, one with 1.25 mm depth (enamel) and another with 2.25 mm depth (dentin), and restored using OMNICHROMA composite resin. The putty index measured the color of the cured composite, and ΔE between the composite and original tooth color was calculated. Statistical analysis: Data analysis included t-tests, correlation coefficients, and Fisher's exact test (α = 0.05). Results: The mean ΔE was 2.39 in enamel cavities and 2.32 in dentin cavities, both within the clinically acceptable range (<3.3). In enamel cavities, the composite color was darker than the tooth, shifting toward green and blue shades. In dentin cavities, the composite color was lighter than the tooth, with shifts toward green and yellow shades. Color matching was slightly better in dentin cavities, but the difference was not statistically significant (p=0.719). Conclusion: OMNICHROMA composite resin's color matching falls within the clinically acceptable range, unaffected by cavity depth.

Climate change and education in shades of blue: between darkness and light with agential realism and object-oriented ontology

Climate change education is infused with images of light. Scholars in the field tend to emphasize hope, sustainability, and solution. They foreground knowledgeable humans who construct better worlds and thereby bind themselves to modern understandings of human being and becoming. I draw on agential realism and object-oriented ontology to contest the metaphor of light, the focus on hope, and the modern premises they rely on—particularly in the context of massive sustainability crises such as climate change. The ethical dimension of agential realism and object-oriented ontology—their call for care and solidarity—offers an alternative to hope, one that aligns well with Kropotkin’s concept of mutual aid. Instead of opening a pathway to sustainability, I understand education as a sphere of human being and becoming that should have its foundation on care and solidarity. As an alternative to the metaphor of light, I develop a metaphor for education in times of crisis: an education ‘in shades of blue.’ Blue is an existential color. It relates to dystopian and utopian images, to issues of power and force, and to solidarity and care.

Effects of chitosan molecular weight and mass ratio with natural blue phycocyanin on physiochemical and structural stability of protein

Phycocyanin (PC), an algae-extracted colorant, has extensive applications for its water-solubility and fresh blue shade. When PC is added to acidified media, dispersions are prone to aggregate and decolorize into cloudy systems. For palliating this matter, chitosan with high, medium, and low molecular weights (HMC, MMC, and LMC) were adopted in PC dispersions, and their protective effects were compared based on physiochemical stabilities. The optimal mass ratio between chitosan and PC was identified as 1:5 based on preliminary evaluations and was supported by the higher ζ-potential (31.0–32.1 mV), lower turbidity (39.6–43.6 NTU), and polyacrylamide gel electrophoresis results. Through interfacial and antioxidant capacity analyses, LMC was found to display a higher affinity to PC, which was also confirmed by SEM images and the maximum increase in transition temperature of their complex (155.70 °C) in DSC measurements. The mechanism of electrostatic interaction reinforced by hydrophobic effects and hydrogen bonding was elucidated by FT-IR and Raman spectroscopy. Further comprehensive stability evaluations revealed that, without light exposure, LMC kept PC from internal secondary structure to external blueness luster to the maximum extent. While with light exposure, LMC was not so flexible as HMC, to protect chromophores from attack of free radicals.

Exploration of violet-to-blue thermally activated delayed fluorescence emitters based on "CH/N" and "H/CN" substitutions at diphenylsulphone acceptor. A DFT study.

The violet-to-blue thermally activated delayed fluorescence (TADF) emitters were created employing several substituents based on 5,5-dimethyl-5,10-dihydropyrido [2,3-b][1,8] naphthyridine-diphenylsulphone (DMDHPN-DPS) called 1a via "CH/N" and "H/CN" substitutions at the diphenylsulphone acceptor (DPS) moiety. The parent compound 1a was selected from our former work after extensive research employing "CH/N" substitution on Dimethyl-acridine (DMAC) donor moiety. There is a little overlap amid the highest occupied molecular orbitals (HOMOs) and lowest un-occupied molecular orbitals (LUMOs) due to the distribution of HOMOs and LUMOs primarily on the DMDHPN donor and the DPS acceptor moieties, respectively. It resulted in a narrower energy gap (∆E ST) between the lowest singlet (S1) and triplet (T1) excited state. In nearly all derivatives, the steric hindrance results in a larger torsional angle (85°-98°) between the plane of the DMDHPN and the DPS moieties. The predicted ΔE ST values of the compounds with "H/CN" substitution were lower than those of the comparable "CH/N" substituents, demonstrating the superiority of the reversible inter-system crossing (RISC) from the T1 → S1 state. All derivatives have emission wavelengths (λ em) in the range of 357-449nm. The LUMO → HOMO transition energies in the S1 states are lowered by the presence of -CN groups or -N = atoms at the ortho or meta sites of a DPS acceptor unit, causing the λ em values to red-shift. Furthermore, the λ em showed a greater red-shift as there were more-CN groups or -N = atoms. Three of the derivatives named 1b, 1g, and 1h, emit violet (394nm, 399nm, and 398nm, respectively), while two others, 1f and 1i, emit blue shade (449nm each) with reasonable emission intensity peak demonstrating that these derivatives are effective violet-to-blue TADF nominees. The lower ΔE ST value for derivative 1i (0.01eV) with λ em values of 449nm make this molecule the finest choice for blue TADF emitter amongst all the studied derivatives. We believe our research might lead to the development of more proficient blue TADF-OLEDs in the future.

New Natural Blue Dye from Water Jasmine (Wrightia Religiosa Benth.) for Silk

ABSTRACT This study investigates the color values and colorfastness of silk fabrics dyed with dye extracted from Water Jasmine (Wrightia religiosa Benth.) using three different alkaline agents: red lime, lime, and sodium carbonate. The color values (L*, a*, b*, C*, h*, and K/S) were measured before laundering to evaluate the color characteristics of the dyed silk. Notably, red lime produced the deepest shade (L* value of 50.46), closely followed by lime (77.07) and sodium carbonate (59.48). The h* values indicated that red lime (246.83) and sodium carbonate (292.17) produced blue shades, while lime (92.54) leaned toward green-yellow. Regarding color strength (K/S), red lime and sodium carbonate exhibited the highest color strength (1.74), whereas lime had the lowest (0.59). After laundering, colorfastness was evaluated using DL*, Da*, Db*, DC*, DH*, and DE* values. Red lime showed the best color durability, with a DE* value of 6.46, indicating fair color retention. Lime and sodium carbonate had poorer color durability, with DE* values of 12.05 and 16.15, respectively. Thus, the results clearly show that Water Jasmine with red lime possesses significant potential for development as a natural dye source, specifically for creating novel blue-colored natural dye material for silk dyeing.

Shades of blue: Nevus of Ota in a child

Shades of blue: Nevus of Ota in a child

Стилевое своеобразие иконописи Карелии XVII–XVIII веков на примере житийных икон, посвященных святителю Николаю

This article analyzes the cult painting of Karelia of the XVII–XVIII centuries on the examples of hagiographic icons dedicated to St. Nicholas. It was in these monuments that an artistic variety of forms emerged, which represented a bizarre combination of new techniques and traditional archaic features. A significant role in updating the visual structure of icons was formed by the Baroque. In the design of architecture, in the technique of writing the open parts of the figure of the Saint, the desire to realize intricate elements was manifested, in particular, the S-shaped line became a marker of the "local" Baroque. Among the isographers, a more refined color, consisting of blue and pink shades, was recognized, and the landscape and the animal world began to play the role of the main subject of the narrative. Some changes have also taken place in the composition, they touched the direct perspective. In icons with folklore semantics, painterly-plastic unity was preserved. This idea was convincingly revealed in the color, the peculiar interpretation of the image of the Saint and the themes caused by the everyday impressions of the northern man. The experience of this study idea to expand the understanding of Karelian icon painting of the late Middle Ages. In contrast to the cult painting of the early period, in the works of the 17th-18th centuries, new trends had a significant impact on the style of icons. But despite this, archetypal artistic thinking and everyday practical experience allowed to save the pre-emptive right to further self-affirmation.

Blue Shades in Plasters: Archaeometric Role in Dating of the Casamassima (Southern Italy) Historical Facades

Casamassima old town, locally known as “blue town”, is widespread stratified blue paint covering the facades of the historical buildings, not reported in the archival data and historical sources. The archaeometric results presented in this study aimed to investigate raw materials, in particular pigments, used to cover the facades to contribute more precisely to the historical reconstruction of this local custom. A set of nine samples was collected from two representative historical buildings and observed by reflected light optical microscopy and scanning electron microscope (SEM-EDS) and their mineralogical characterisation was carried out by means of X-ray powder diffractometry (XRPD). The comparison of the mineralogical and elementary results and the stratigraphic, morphological, and microstructural observations made it possible to highlight a significant stratification of these plasters and to recognize the artificial ultramarine blue applied with lime, as the main mineral pigment, together with red ochre and blanc fixe. The identification of pigments was crucial to date the blue plasters.

A Physicochemical Examination of Blue Shades in Pottery: Rich, Deep and Endless

This study attempts to take aspects of pottery technology into account while concentrating on the blue pigment and glaze recipes of various kinds of glazed pottery types; that is to say, Iznik ware, Kütahya ware, Miletus ware, glazed fritware, porcelain, polychrome glazed ware, and monochrome glazed ware were collected from a rescue excavation site within the Castle of Mytilene in Lesvos Island, Greece. The decoration, surface treatment, and production technology were investigated on the basis of 23 ceramic fragments that can be dated to the Turkish/Venetian period. The present study concerns the manufacture of glazed pottery, and in particular, colour recipes and issues of glaze technology. This study endeavoured to look into the specifics of the medieval colour recipes used on the glazed ceramics from Mytilene. This was accomplished by using an analytical process that took into account the compositional information of blue pigments, glazes, and slip coatings. The chemical analysis was conducted using scanning electron microscopy (SEM-EDS), Raman spectroscopy provided information about the compositional variation, and the optical examination via optical microscopy (OM) and scanning electron microscopy (SEM-EDS) yielded information about the sample stratigraphy of the examined ceramic sections. This investigation into glazed ceramics was able to define and reflect the key aspects of each society’s perception of colour through a large variety of colour and glaze recipes.

New blue pigments based on Co2+ and La3+ doped hibonite for NIR-reflective coatings

New blue pigments based on Ca1-xLaxAl12-xCoxO19 (x = 0–0.5) were obtained by the combustion method, avoiding the expensive annealing step. The obtained pigments have a specific surface area between 3 and 5 m2/g. The crystallite size of Ca1-xLaxAl12-xCoxO19 pigments decreases from 44 to 26 nm, as the substitution degree, x, increases from 0 to 0.5 apfu. Despite the low Co2+ content (<4% mass), the pigments show intense blue shades and high total solar reflectance. CIE L∗/a∗/b∗ parameters show that, with the increase of chromophore content from 0.1 apfu (73.3/-2.6/-34.1) to 0.5 apfu (60.5/2.6/-47.0) the blue color of the pigments intensifies, whilst the total solar reflectance decreases from 70.7% (x = 0.1) to 59.6% (x = 0.5). The tests performed confirmed the possibility of using Ca1-xLaxAl12-xCoxO19 pigments in making cool, NIR-reflective coatings.

Height Control of Greenhouse-grown Pansy Using Colored Shade Nets

Pansy (Viola ×wittrockiana) is a greenhouse crop commonly grown under black shade net; it often requires the use of chemical plant growth regulators to maintain a compact growth habit. Nonchemical efforts to alter plant morphology, such as height, would provide a more sustainable solution than chemical application. The objective of these studies was to evaluate the effects of different colors of shade nets on controlling growth and flowering of pansy. In Expt. 1, ‘Clear Yellow’, ‘Buttered Popcorn’, and ‘Deep Orange’ pansy plugs were placed under 30% blue or black shade net or, as a control group, where grown with no shade net. In Expt. 2, the same three cultivars of pansy were grown under 50% black, red, pearl, or aluminized shade net. Data were collected on plant height, plant width, flower number, plant survival, soil plant analysis development chlorophyll meter (SPAD) readings, and light quality. In Expt. 1, the blue shade net reduced height to flower and height to leaves, but also decreased flower number and plant survival as compared with black shade net. All plants under no shade died. In Expt. 2, SPAD, an indicator of plant quality by estimating leaf greenness, was found to be lower under black shade net, whereas pearl shade net led to a decrease in plant height and no effect on the number of flowers. Light quality, including red-to-far-red ratio, varied among shade treatments, whereas light intensity was reduced under aluminized, black (50%), and red shade nets compared with other shade treatments. Blue and pearl shade nets both reduced plant height, but blue shade net also reduced plant survival and flowering.