Phosphor Efficiency Research Articles

Clonal variation in growth, PSII photochemical activity and polar metabolites in Pinus elliottii × P. caribaea

Pinus elliottii × P. caribaea is a widely planted commercial tree hybrid in South China. To investigate the potential of physiological parameters for clonal selection, cuttings of three clones (EH3, EH4 and EH5) and a control were grown in phosphorus treated pots. Significant variations to phosphorous, photosystem II activity and polar metabolite abundance in needles were noted among clones. Clone EH5 was the most P-responsive and had maximum height growth. The highest maximum quantum yield of PSII in the dark (Fv/Fm), maximum quantum yield of PSII in the light (Fvʹ/Fmʹ) and the actual PSII efficiency (ΦPSII) values were also found in EH5. A total of 64 polar metabolites were identified, 21 were regulated by phosphorous, while 28 accumulated differentially among the three clones. There were few overlapping responsive metabolites to phosphorous fertilization. In EH5, the abundance of maltotriitol, neohesperidin and raffinose were highest, whereas galactinol and shikimic acid were lower compared with EH3 and EH4. The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency.

Investigating the effect of Aspergillus niger inoculated press mud (biofertilizer) on the potential of enhancing maize (Zea mays L.) yield, phosphorous use efficiency, and phosphorous agronomic efficiency

The world is facing tremendous challenges in tackling waste diversion from landfill to resource recovery. Conversion of organic waste into biofertilizer would reduce its environmental impacts by improving soil nutrient contents level and decreasing the requirements of mineral fertilizer (MF). Phosphorus (P) is the primary least available mineral in many cropping environments. The current study was aimed to isolate an efficient P-solubilizing fungi and to investigate its influence on total organic carbon (TOC), C/N ratio, total nitrogen (TN), total phosphorous (TP), total potassium (TK), and germination index (GI) of press mud to convert into biofertilizer. P from biofertilizer was then evaluated in different treatments in terms of maize biological yield, grain yield, P use efficiency (PUE), and P agronomic efficiency (PAE) in comparison to MF. Among seven P-solubilizing fungal isolates, A. niger was selected for its highest P-solubilizing activity in solid (1.5 cm) and liquid media (389 ug/ml) by solubilizing insoluble tricalcium phosphate (TCP). It was also found to mobilize zinc (Zn) from insoluble zinc oxide (ZnO). Bio-augmentation of press mud with A. niger shortens maturity period, improved nutrient contents and GI. Analysis of maize in different treatments revealed that P from mineral and biofertilizer enhanced crop yield. The competency of treatments was measured on higher PUE and PAE. Higher grain yield and harvest index (HI) were achieved in T5(100%Org+50%MF) containing a higher amount of P from mineral and biofertilizer. However, higher PUE and PAE were found in the order T6>T5>T2>T3>T4>T1, demonstrating the importance of integrated and balanced use of fertilizers.

Effect of Foliar Application of Nano Nutrients and Amino Acids as a Complementary Nutrition on Quantity and Quality of Maize Grains

In order to study the effect of foliar application of nano-NPK, nano-micronutrients, and nano-amino acids on the growth and yield of maize (Hybrid F1 Furat), a field experiment was carried out during the autumn season (2019) with an area of 1500 m2g within the district of (41)–Al-Husseiniyah / Al-Talea’a district / Babylon Governorate according to Randomized Complete Block Design (RCBD) for two factors with three replicates. The first factor (nano-NPK) included three treatments: control, nano-NPK (20-20-20), and nano-NPK (12-12-36), while the second factor (nano-micronutrients and nano-amino acids) included four treatments: control, nano-micronutrients, nano-amino acids, nano-micronutrients + nano-amino acids. The studied indicators on maize plant included estimation of nutrient absorption in grains and total absorption (kg H-1), estimation of fertilizer application efficiency (%). The results showed the significant superiority of NPK (12-12-36) spraying in achieving the highest averages of the studied indicators by an increase of (61.53%) in comparison with the comparison treatment for the total absorbed potassium, and an increase of iron and copper absorbed in the grains reached (3.938% and 22.321%), respectively, in comparison with the comparison treatment. And the application of the integrated nano-element fertilizer + nano amino acids achieved The highest averages of iron, manganese and copper absorbed in grains increased by (39.010%, 28.409%, 60.577%), respectively, comparing with the comparison treatment. and the interaction of the two study factors gave the combination of nano NPK (20-20-20) with integrated nano micro elements + nano amino acids the highest averages of nitrogen and phosphorus total absorption and for iron, manganese and copper with an increase of (110.06%, 81.83%, 64.251%)., 74.065%, 109.375%), respectively, by comparison with the comparison treatment. The highest nitrogen and phosphorous utilization efficiency was recorded at 55.12 and 36.65%, respectively, in comparison with high-potassium nano NPK, which corresponds to the combination of high-potassium NPK nano with nano (trace elements + amino acids) in recording the highest potassium utilization efficiency of 58.51% in comparison with the balanced nano NPK.

Influence of interstitial UO22+ doping on the valence control of Eu and energy transfer to substitutional Eu3+ and Sm3+ in SrBPO5.

Controlling the valence mixing of Eu3+/Eu2+ and energy transfer between activator ions in solid solution is an important process to improve the efficiency and specificity of phosphors. In this work, the structural and optical properties of stillwellite type SrBPO5 doped with uranium/europium/samarium, as prepared by conventional solid-state reaction synthesis, were investigated. PXRD studies and Rietveld analysis were carried out to determine the structure, phase purity, and coordination environment of the dopants in the host matrix. Samarium existed only as a trivalent cation in SrBPO5 synthesised in an air atmosphere, whereas europium exhibited abnormal reduction and Eu2+ co-existed with Eu3+. Unlike Eu and Sm, which replaced Sr at its sites, uranium gets stabilised as UO22+ in the interstitial vacant space in the SrBPO5 lattice. Uranium co-doping strongly influenced the Eu valence distribution by favouring the re-oxidation of Eu2+ to Eu3+. Possible mechanisms of Eu abnormal reduction in SrBPO5 and Eu valence control based on the electron transfer from substitutional Eu2+ to interstitial UO22+ are discussed. The photoluminescence and time-resolved photoluminescence properties of Eu/Sm/U doped SrBPO5 were investigated systematically. Uranium co-doping significantly enhanced the emission intensities of trivalent Eu and Sm through the exchange-type energy transfer. Besides, the Eu3+ luminescence intensity was further amplified in the presence of uranium due to the partial oxidation of Eu2+ to Eu3+. By controlling the uranium to Eu concentration ratio, the Eu-SrBPO5 phosphor could be tuned to different CIE coordinates.

High partial thermal conductivity of luminescence sites: a crucial factor for reducing the heat-induced lowering of the luminescence efficiency

The high partial thermal conductivity of luminescence sites is associated with the reduction of the heat-induced lowering of the luminescence efficiency of phosphors. This finding may be helpful for screening efficient phosphors.

Organomineral gübre ve K-humat’ın tane mısırın verim ve fosfor kullanım etkinliği üzerine etkilerinin kimyasal gübreyle karşılaştırması

Bu çalışma, kimyasal ve organomineral gübre ve K-Humat’ın uygulamalarının tane mısırın fosfor kullanımı üzerine etkilerini belirlemek için yapılmıştır. Tesadüf blokları deneme desenine göre üç tekerrürlü olarak kurulan denemede ekim esnasında U1 (%100 P) kimyasal gübre (13.24.12-10 SO3+1 Zn), U2 (% 100 P) ve azalan oranlarda U3 (%80 P), U4 (%60 P), U5 (%40 P) organomineral gübre ile (7.16.10-15 SO3+ 1 Fe+ 0.5 Zn+ 20 organik madde ) ve 6 L da-1 K-Humat (% 12 Humik+fulvik asit) ve kimyasal gübre ile azalan oranlarda U6 (%100 P), U7 (%80 P), U8 (%60 P), U9 (%40 P) fosfor uygulanmıştır. Çalışmada tepe püskülü oluşum döneminde mısır bitkisinin yapraklarındaki besin elementlerinin değişimine gübre uygulamaları etkili olmamış ve mısır bitkisi için bildirilen sınır değerlerine göre yapraklarda bütün besin elementlerinin yeterli düzeyde olduğu belirlenmiştir. Gübre uygulamalarının düzeltilmiş tane verimine etkisi önemsiz, fosforun agronomik ve geri alım etkinliğine etkisi istatistiki olarak (P

Phosphorous Use Efficiency and Its Requirement for Aloe Vera Cultivated on Silty Loam Soils

ABSTRACT Balanced application of phosphorus (P) fertilizer is important for productive agricultural systems with a reduced environmental footprint. This study aimed to assess the effect of P on the leaf yield, P use efficiency, P concentration and uptake by Aloe vera. A pot trial experiment was conducted using a completely randomized design, with six levels of P applied at 0, 30, 45, 60, 80, and 120 kg ha−1, replicated in triplicate. The results revealed that yield attributes, leaf yield, P concentration and uptake were significantly improved with P application and optimum results were obtained when P was applied at 80 kg ha−1. The addition of P increased leaf yield by 33 to 91% compared to the untreated control. Likewise, the highest numbers of suckers, leaves, fresh and dry gel weight, and profit based on benefit cost ratio was recorded with this treatment. In contrast, the highest P concentration and uptake by the leaf were observed at the highest P treatment rate of 120 kg ha−1. The highest plant height, leaf area and fresh gel weight were responsible for the production of higher leaf yield. The minimum amount of P for 80% leaf biomass production was estimated to be 43.9 kg ha−1 whereas the critical leaf P concentration was 0.62% for Aloe vera cultivation. The result suggests that application of 80 kg P ha−1 could produce economically higher yield of A. vera, and further investigation is now required to validate these results for other soil types under field conditions.

Sweet Corn Phosphorus Uptake from Sandy Soil Amended with Anaerobically-digested Manure

ABSTRACT Anaerobic digester development on dairy, poultry, and swine confined animal feeding operations (CAFOs) reduce manure storage, produce energy and are poised to supply a variety of nutrient-rich materials. Field experiments were conducted in the Columbia Basin of South-Central Washington to evaluate the yield response and phosphorous (P) use efficiency of sweet corn (Zea mayes convar. saccharata cv. Sheba) to the application of P from anaerobic-digested manures. Treatments consisted of the application of 0, 10, 20, 40 kg P ha−1 from five sources, three from anaerobic digesters (AD); AD-dairy P fine solids; AD centrifuged poultry solids; and AD dairy-derived struvite-P compared to a commercial poultry fertilizer, commercial mono-ammonium phosphate, and a non-amended control. Sweet corn yields were not significantly different among P amendments or rates of application but were different between years and were greater than the No-P treatment in 2014. Phosphorus recovery efficiency defined as that percentage of applied P recovered by sweet corn averaged 138% among treatments receiving 10 kg P ha−1 and declined to 57% for higher rates of poultry materials and the commercial mono-ammonium phosphate (MAP) in 2013 and declined 50% in 2014 due to lower yields. Although yield was not different the uptake of P among treatments was significantly greater than the unfertilized control. The lack of yield differences among rates of P applied indicates that P was not limiting yield and suggests that under these production conditions the application of 10 kg P ha−1 of any of the amendments was sufficient. Abbreviations: AD: anaerobic digestion; ADD: anaerobic-digested dairy manure; ADP: anaerobic digested poultry manure; ADS: anaerobic-digested struvite; DM – dry matter; MAP – mono ammonium phosphate; PBP a commercial poultry fertilizer; PRD: percent P recovery efficiency difference method; PRB: percent P recovery balance method; PUE: Phosphorus use efficiency; AUE – Agronomic utilization efficiency.

Plant growth-promoting rhizobacteria (PGPR) improve the growth and nutrient use efficiency in maize (Zea mays L.) under water deficit conditions

Drought is one of the major abiotic stresses that affects crop yield worldwide. An eco-friendly tool that can broadly improve plants' tolerance to water stress is bioionocula comprising plant growth-promoting rhizobacteria (PGPR). In this study, the effect of two PGPR Cupriavidus necator 1C2 (B1) and Pseudomonas fluorescens S3X (B2), singly and/or co-inoculated at two inocula sizes (S1 - 3 × 103 cells g−1 dry weight (dw) soil and S2 - 3 × 106 cells g−1 dw soil), on growth, nutrient uptake, and use efficiency was assessed in maize (Zea mays L.) plants grown at three levels of irrigation (80% of water holding capacity (WHC) – well-watered, 60% of WHC - moderate water deficit stress, and 40% of WHC - severe water deficit stress) in a greenhouse experiment. The impact of water deficit and bioinoculants on soil microbial activity (fluorescein diacetate hydrolysis) was also evaluated.Moderate and severe water deficit negatively affected soil microbial activity, as well as, maize growth, by reducing plants' shoot biomass and increasing root/shoot ratio at 60 and 40% of WHC. Bioinoculants mitigated the negative effects on shoot biomass, especially when PGPR were co-inoculated, increasing up to 89% the aerial biomass of plants exposed to moderate water deficit. Bioinoculation also increased nitrogen (N) and phosphorous (P) use efficiency, which may have led to higher maize growth under water deficit conditions. The size of the inocula applied had marginal influence on biometric and nutrient parameters, although the higher concentration of the mixture of PGPR was the most effective in improving shoot biomass under moderate water deficit.This study shows that rhizobacterial strains are able to increase nutrient use efficiency and to alleviate water stress effects in crops with high water demands and have potential applications to keep up with productivity in water stress scenarios.

Mixed culture microalgae removal for water quality improvement using chitosan

The presence of microalgae affects water quality and beneficial uses of surface freshwaters. Chitosan with proven potential for harvesting specific microalgae species from their culture medium to produce biofuels and bioproducts also appears promising for efficient removal of mixed microalgae species from surface freshwaters. The main focus of the present study was on removal of mixed microalgae species using chitosan as a coagulant to help improve water quality. Important operational parameters were optimized for economical microalgae removal. The microalgae cells, chlorophyll-a, total nitrogen, and total phosphorous removal efficiency were 82.06%, 89.90%, 69.32%, and 44.01%, respectively, at an optimum chitosan dose of 10 mg/L, pH 8, slow mixing time 7 min, slow mixing rate 30 rpm, and settling time of 15 min. The results show that chitosan coagulation efficiently removed mixed microalgae species from surface freshwater with significant improvement in water quality and recovery of algal biomass for other beneficial applications.

Highly efficient phosphor-glass composites by pressureless sintering

The development of high-power white light-emitting diodes demands highly efficient and stable all-inorganic color converters. In this respect, phosphor-glass/ceramic composites show great promise as they could combine the merits of high quantum efficiency of phosphors and high chemical and thermal stabilities of glass/ceramic matrices. However, strong interfacial reaction between phosphors and matrices at high temperature results in quantum efficiency loss of the embedded phosphors, and traditional solutions rely on high-pressure consolidation techniques. Here we report the intrinsic inhibition of interfacial reaction by using silica glass rather than multicomponent glasses as the matrix. The embedment of phosphors is achieved via a pressureless sintering method, rendering these color-tunable phosphor-glass composites not only accessible to three-dimensional printing technique, but also highly efficient (internal quantum efficiency >90.0%), thermally stable at 1200 °C and hydrothermally stable at 200 °C. Our results provide a facile and general strategy for developing all-inorganic functional composites.

Organic Manure Amended with Phosphate Solubilizing Bacteria on Soil Phosphorous Availability

Purpose : Combine use of phosphate solubilizing microorganisms and organic manure has greater agronomic utility as it could improve phosphorous (P) utilization efficiency through conversion of insoluble P to accessible forms. Therefore, the present study was conducted to assess the effect of different organic manures (poultry manure, goat manure and cow dung) with phosphate solubilizing microorganism on phosphorous availability.Research Method : The phosphate solubilizing bacterial (PSB) strain employed in this study was isolated from soil samples collected from agricultural lands in Matara District of Sothern Sri Lanka. The strain was identified as Enterobacter cancerogenous. Eight treatment combinations each replicated three times were used in the study. Findings : P availability of organic manure amended soils was progressively increased irrespectively the inoculation of PSB strain. The bulk of the increment occurred during the first 2 to 3 weeks of the incubation followed by slight reductions at the later stages. P availability of the soil amended with organic manures was significantly (P ≤ 0.05) higher than that of the control. Furthermore, the specified were much higher when PSB was inoculated to the soil amended with organic manures. PSB inoculants were used with poultry manure showed the highest P availability.Originality / Value : The availability of soil phosphorous is enhanced by combine use of organic manures and PSB inoculants; the practice is suggested to be employed in integrated nutrient management strategies.

Water Polishing improved controlled-release characteristics and fertilizer efficiency of castor oil-based polyurethane coated diammonium phosphate

The production cost of controlled-release fertilizers is an important factoring limiting their applications. To reduce the coating cost of diammonium phosphate (DAP) and improve its nutrition release characteristics, the fertilizer cores were modified by water polishing with three dosages at 1, 2, and 3%. The effects of modification were evaluated in terms of particle hardness, size distribution, angle of repose and specific surface area. Castor oil-based polyurethane was used as coating material for fertilizer performance evaluation. A pot experiment was conducted to verify the fertilizer efficiency of coated diammonium phosphate (CDAP) with maize. The results showed that polishing with 2% water reduced the angle of repose by 2.48–10.57% and specific surface area by 5.70–48.76%, making it more suitable for coating. The nutrient release period of CDAP was significantly prolonged by 5.36 times. Soil available phosphorous, enzyme activities, maize grain yield, and phosphorous use efficiency were all improved through the blending application of coated and normal phosphate fertilizer. This study demonstrated that water-based surface modification is a low-cost and effective method for improvement and promotion of controlled release P fertilizers.

Theoretical design and characterization of high efficient Sr9Ln(PO4)7: Eu2+ phosphors

Substitution of Ln site in Sr9Ln(PO4)7: Eu2+ [Ln = Sc, Lu, Y, La] matrix prepared from powder-based precursors were designed for the first time. By modulating the lanthanide such as Sc, Lu, Y and La, the corresponding luminescence varied hues from yellow to blue light under 360 nm excitation. The Rietveld refinement verified the successful substitution for Ln3+ site, and the samples crystallized with the space group of I2/a for Sc, Lu, Y and R-3m for La, respectively. The internal quantum yield was found to be 24 %, 87 %, 91 %, and 100 %, respectively. The highest quantum yield phosphor of Sr9La(PO4)7: Eu2+ has potential to overcome the low efficiency of the commercial phosphors. Moreover, it possesses a high thermal quenching behavior up to 90 % emission at 423 K compared to room temperature. Therefore, a series of Sr9Ln(PO4)7: Eu2+ phosphors are expected to be exploration of technologically important material as excellent wavelength-conversion phosphor.

Eu3+-activated Ca3Mo0.2W0.8O6 red-emitting phosphors: A near-ultraviolet and blue light excitable platform for solid-state lighting and thermometer

Eu3+-activated Ca3Mo0.2W0.8O6 phosphors, which presented bright red emissions mainly from the 5D0 → 7F2 transition of Eu3+ ions upon the near-ultraviolet and blue light excitation, were successfully prepared by a traditional high-temperature technology. The crystal structure, phase constitution, morphology, electronic structure, photoluminescent behaviors, decay time, internal quantum efficiency and thermal stability of the resultant phosphors were investigated in detail. Under the excitation of 365, 393 and 465 nm, the optimal doping concentration was 9 mol% and the electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in Ca3Mo0.2W0.8O6 host lattices. Additionally, through using the prepared compounds, commercial blue/green-emitting phosphors and light-emitting diodes (LEDs), the fabricated white-LEDs emitted warm white light with excellent performance, such as good CIE coordinates, high color rending index and low correlated color temperature, when driven by 30 mA of injection current. Ultimately, according to the response of the decay time to the temperature, the thermometric performances of the resultant phosphors in the temperature range of 298–573 K were studied. The maximum sensor sensitivity of the studied phosphors reached up to 1.16% K−1 at 523 K. These achievements revealed that Eu3+-activated Ca3Mo0.2W0.8O6 phosphors were promising candidates for solid-state lighting and thermometer.

Consortium of endophyte and rhizosphere phosphate solubilizing bacteria improves phosphorous use efficiency in wheat cultivars in phosphorus deficient soils

Rhizospheric and endophytic bacteria are known to increase phosphorus efficiency (PE) of plant in phosphorus-deficient soils. The purpose of this research was to examine the role of rhizospheric and endophytic bacterial inoculation in increasing phosphorus acquisition efficiency (PAE) and phosphorus utilization efficiency (PUE) by solubilization of phosphate and expanding of root system. A total of 22 isolates were selected from rhizosphere and inside root of wheat (Triticum aestivum L.) plants based on plant growth promoting traits. These isolates significantly solubilized phosphorus from tri-calcium phosphate and produced indole-3-acetic acid (IAA) under in vitro condition. In pot experiment, we found that rhizospheric and endophytic bacterial inoculation improved root and shoot dry matter, grain yield, length, surface area and volume of roots. At the ripening stage, the consortium treated (co-inoculation with rhizospheric and endophytic bacteria) pots exhibited enhanced the plant height (up to 15.0% and 11.0%), shoot dry weight (up to 5.8% and 7.5%), root dry weight (up to 68% and 58%) and grain yield (up to 58.0% and 42.0%), in Marvdasht and Roshan cultivars respectively. The uptake of P was 3.61 mg pot−1 for Marvdasht cultivar and 6.44 mg pot−1 for Roshan cultivar. Inoculation with rhizospheric isolate increased PE index by 29.5% and 18.7% in Marvdasht and Roshan cultivars, respectively. Noticeable effect was detected in case of consortium treatment, suggesting that plant growth promoting rhizobacteria acted synergistically with plant growth promoting endophytes. Finally, our study highlights the importance of co-inoculation with rhizospheric and endophytic bacterial inoculant in improving P efficiency of wheat cultivars.

Synthesis, structure and luminescence of a high-purity and thermal-stable Sr9LiMg(PO4)7: Eu3+ red phosphor

Eu3+-activated Sr9LiMg(PO4)7 phosphors, which presented bright red emissions mainly from the 5D0→7F2 transition of Eu3+ ions upon the near-ultraviolet excitation, were successfully synthesized in ambient atmosphere. The crystal structure, phase constitution, photoluminescent behaviors, decay time, internal quantum efficiency and thermal stability of the resultant phosphors were investigated in detail. Eu3+ ions are found to tend to occupy multiple Sr2+ sites, which are 7, 8 and 10-coordinated. The optimal doping concentration is 7 mol% and the electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in Sr9LiMg(PO4)7 host lattices. Temperature-dependent PL spectra indicated Sr9LiMg(PO4)7: Eu3+ possess excellent emission and color stability at elevated temperature. Fabricated single-chromatic LED prototype emit bright red light under 20 mA bias current, which demonstrates that Sr9LiMg(PO4)7: Eu3+ phosphor is of great potential as converted phosphor in NUV LED application.

Efficient blue-white color luminescence with near-ultraviolet excitation in Dy3+/Tm3+:Na3Gd(PO4)2 nanophosphor for white LEDs

The Dy3+, Tm3+ ions activated, and Dy3+/Tm3+ ions co-activated Na3Gd(PO4)2 phosphors were synthesized by the citrate-gel based combustion technique. The structural properties of as-synthesized phosphors were studied through X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The influence of Tm3+ concentration on the fluorescence properties of Na3Gd(PO4)2:Dy3+/Tm3+ phosphors were systematically investigated under near-UV light irradiation of 359 and 352 nm. The energy transfer efficiency (ηET) of as-prepared phosphors increases gradually from 17 to 42%, and the critical distance (Rc) between Dy3+ and Tm3+ ions is calculated to be 4.76 Å. For better understanding the energy transfer mechanism (ET:Dy3+ →Tm3+), the decay curves were utilized on the basis of Dexter's energy transfer formula and Reisfeld's approximation. More importantly, the obtained CIE color coordinates of Na3Gd(PO4)2:Dy3+/Tm3+ phosphors located at blue-white region under near-UV light irradiation. The results demonstrate the promising application of Na3Gd(PO4)2:Dy3+/Tm3+ phosphor for near-UV white LEDs.

A laser current control algorithm to avoid color distortion in laser projection displays

AbstractLaser display technology has gradually become an important solution for large screen display. As a mature lighting technology in recent decades, phosphor has been widely used in the field of lighting and display. As a solid‐state light source, it has the advantages of low power consumption, environmental protection, rich color, and dynamic modulation. The luminescent efficiency of phosphors varies with temperature, which results in the nonlinearity of phosphor emission when the light source is dynamically modulated and the color temperature drift of the display image. In this paper, a control model of color temperature of laser TV display changing with laser current and temperature is established. The color temperature of laser TV is corrected by using current compensation control algorithm. The problem of color temperature drift caused by the change of phosphor conversion efficiency with t7emperature is solved. The color temperature deviation is 1118 K in the luminance range of the light source before compensation. By compensating and controlling the laser current, the ratio of blue light and phosphor is constant when the luminance changes, thus ensuring the color temperature constant when the luminance of the laser light source changes. The color temperature deviation is 50 K in the luminance range. By analyzing the different luminance of the display image, the stability of the color temperature is improved.

Effects of vermicompost placement on nutrient use efficiency and yield of tomato (Lycopersicum esculentum)

ABSTRACTThis study investigated different methods of applying vermicompost (VC), with the aims of improving yield in organic tomato production and decrease the amount of fertiliser required. Three methods of placement (application) of the VC were used in the field trial: a) VC placed in a row on the soil surface with incorporation behind the planting lines (R), b) broadcast in the field (B), and c) in the transplant hole under the root plug of the transplant (U). As a second factor, VC was applied at three different rates of application (3, 6 and 9 t ha−1 for R and B, and 2, 4 and 6 t ha−1 for U). In both years, the different rates and placement methods had no significant effect on the fresh yield of tomatoes. However, in 2015, the treatment with the higher rate and the U placement of the VC increased the dry matter (DM) yield of the plants by up to 48% (8.4 t ha−1). Evidently, treatments with the U method had 23 % higher nitrogen (N) uptake (156 kg ha−1) compared with the treatments where VC was broadcast in the field (121 kg ha−1). In 2015, the N use efficiency was significantly higher for the U method (102%) compared with the R and B methods (38 and 34%, respectively) and the phosphorous and potassium use efficiency followed a similar pattern. The study demonstrated that the U placement method for VC increased DM yields, nutrient uptake and nutrient use efficiency in organic tomato production.