Full Sun Exposure Research Articles

Pittosporum tobira 'Wheeleri' Wheeler's Dwarf Pittosporum

This document provides an overview of Wheeler’s dwarf pittosporum, an evergreen shrub known for its compact, rounded form and dark green foliage. It details the plant’s characteristics, including its moderate growth rate, dense texture, and specific leaf and flower attributes. The document also covers the plant’s preferred growing conditions, such as its need for well-drained soil and partial to full sun exposure, and highlights its uses in landscaping, particularly in coastal areas. Additionally, it notes the plant’s susceptibility to certain pests and diseases, emphasizing the importance of proper maintenance and care. Original publication date October 1999.

Flying microbes-survival in the extreme conditions of the stratosphere during a stratospheric balloon flight experiment.

Earth's stratosphere is a hostile environment that has challenged microbial survival. We set out to test the effect of stratosphere exposure on survival of single species (Bacillus subtilis) and complex microbial communities from soils and sediment. B. subtilis survival was strongly impacted by sun exposure, i.e., ultraviolet (UV) radiation, with only 1% survival at full sun exposure. Complex microbial communities had high survival rates, and the soil or sediment matrix may have provided protection against radiation and desiccation, supporting the survival of environmental microorganisms.

Growth regulators on shooting and adventitious rooting of Mimosa caesalpiniifolia adult stem cuttings

Mimosa caesalpiniifolia, crucial for fencing and firewood in Brazil's Caatinga dry forest, presents a promising avenue for commercial propagation. The challenges faced in seed propagation, such as the scarcity of inputs and the difficulties in overcoming dormancy, highlight the advantages of vegetative methods. These methods emerge as a viable alternative, enabling uniform and large-scale production of clonal plantlets. This technique ensures consistent plant quality, which is crucial given the wide variety of uses for this species. Additionally, the use of plant growth regulators is critical to enhance the success of vegetative propagation, promoting the formation of robust roots and overall development of plants from cuttings of adult trees. Recognizing the significance of creating clonal forests of M. caesalpiniifolia and the necessity for understanding methods to expedite this endeavor, this study was designed to assess the shooting and adventitious rooting of stem cuttings sourced from adult M. caesalpiniifolia trees, examining the effects of auxinic agents. M. caesalpiniifolia cuttings were harvested through vegetative rescue from six randomly selected adult trees, treated with indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) at concentrations of 0, 1,000, 2,000, and 4000 mg L−1, using a completely randomized design in a 2 × 4 factorial arrangement. The evaluations included assessing root presence, number of shoots, vigor of clonal plantlets and plant survival under greenhouse conditions, shade house conditions, and full sun exposure. The study did not reveal any significant interaction between growth regulators and their concentrations under these conditions. IBA at intermediate concentrations enhanced root growth, while cuttings without growth regulators exhibited superior aerial development. A decrease in survival percentages with increasing concentrations of regulators was observed, while cuttings without regulators demonstrated better morphological development. The study suggests for large-scale nurseries, natural rooting and shoot formation in M. caesalpiniifolia cuttings may suffice for successful propagation without IBA or IAA.

Experimental and numerical investigation of thermal environment of the child trapped in a parked vehicle

Pediatric vehicular hyperthermia (PVH) has aroused wide public concern recently. High temperatures in closed vehicles with full sun exposure and no ventilation in summer seriously endanger children's lives. Aiming at this practical problem, this study first took the temperature of child’s core body as a standard, and divided the hyperthermia into three stages: un-compensable heating (Tc > 37ºC), heat stroke (Tc > 40ºC) and critical thermal maximum (Tc > 42ºC). On this basis, two weeks of outdoor parking experiments during 10:00–18:00, using an equivalent size dummy were conducted to explore the influence of ambient temperature and solar irradiation on cabin temperature, humidity, and child’s core body temperature. According to the experimental results, at an ambient temperature of 32.4ºC, the child in the cabin developed un-compensable heating within 72 min, suffered heat stroke within 129 min, and reached the critical thermal maximum within 151 min. Considering the limitations of the experiment, a numerical study was conducted to analyze the effects of ambient temperature, solar irradiation, and window radiation characteristics on cabin temperature and flow fields comprehensively. Simulation results were in good agreement with the experiments: even at low ambient temperature Ta = 23ºC or weak solar irradiation (ts = 18:00) condition, the temperature in a closed compartment could reach the "hazardous" level. This study can provide guidance for public to increase security and prevention awareness, and promote the development of relevant policies and technologies.

Effect of Microclimate on the Mass Emergence of Hypothenemus hampei in Coffee Grown under Shade of Trees and in Full Sun Exposure.

The rainfall regime has a significant impact on the microclimate and mass emergence of the coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae) (CBB). Little is known, however, about the shade tree-microclimate-CBB mass emergence interaction. The objective of the present study was to compare the effect of microclimate on the mass emergence of CBB in a full sun-exposed plot with a plot shaded by trees. The experiment was conducted on a Robusta coffee farm in southern Chiapas, Mexico. In each plot, 18 traps baited with an alcohol mixture were installed to capture flying females, collecting caught individuals every hour from 8:00 to 18:00 h. A meteorological station recorded several microclimatic variables on 13 weekly sampling dates from February to May 2022. Significantly more CBB females were captured in the shaded plot. The largest number of CBB captures was recorded between 14:00 and 16:00 h for the shade plot and between 15:00 and 17:00 h for the sun-exposed plot. The mass emergence of CBB showed a positive association with precipitation, dew point, and wind speed samples and a negative association with maximum air temperature, average relative humidity, ultraviolet radiation, wind speed, and equilibrium moisture content. Our observations show that the relationship between shade trees, microclimate, and mass emergence of CBB is complex and that its study helps us to gain deeper insight into CBB bioecology and advance control techniques against this important pest.

Disinfection of Phi6, MS2, and Escherichia coli by Natural Sunlight on Healthcare Critical Surfaces.

Ultraviolet (UV) radiation systems, commonly used to disinfect surfaces, drinking water, and air, stem from historical practice to use sunlight to disinfect household items after contagious illness. Currently, it is still recommended in viral outbreak contexts such as COVID-19, Ebola, and Marburg to expose soft surfaces to sunlight after washing with detergent or disinfecting with chlorine. However, sunlight that reaches the Earth's surface is in the UVA/UVB wavelengths, whereas UV disinfection systems typically rely on biocidal UVC. Our goal was to fill the evidence gap on the efficacy of sunlight disinfection on surface materials common in low-resource healthcare settings by seeding four surfaces (stainless steel, nitrile, tarp, cloth) with three microorganisms (viral surrogate bacteriophages Phi6 and MS2 and Escherichia coli bacteria), with and without soil load, and exposing to three sunlight conditions (full sun, partial sun, cloudy). We conducted 144 tests in triplicate and found: solar radiation averaged 737 W/m2 (SD = 333), 519 W/m2 (SD = 65), and 149 W/m2 (SD = 24) for full sun, partial sun, and cloudy conditions; significantly more surfaces averaged ≥4 log10 reduction value (LRV) for Phi6 than MS2 and E. coli (P < 0.001) after full sun exposure, and no samples achieved ≥4 LRV for partial sun or cloudy conditions. On the basis of our results, we recommend no change to current protocols of disinfecting materials first with a 0.5% chlorine solution then moving to sunlight to dry. Additional field-based research is recommended to understand sunlight disinfection efficacy against pathogenic organisms on healthcare relevant surfaces during actual outbreak contexts.

Bioprospeksi Bunga Lolipop (Pachystachys lutea Nees) sebagai Sumber Alternatif untuk Produksi Gula

The lollipop plant (Pachystachys lutea Nees) has been known as an ornamental plant species that originated from the South America region. In Indonesia, some local children claim that the nectar of this flower has a very sweet flavor. This fact has inspired this short bioprospecting study of the lollipop plant with aim to discover its nectar as a potential alternative sugar source. The study was conducted in Bandung, West Java, Indonesia. Four lollipop plants from three different shading level (one plant in full shade andpartial shade, and two plant in full sun exposure) were sampled as many as five flowers from each plant and their nectar droplets, measured using brix refractometer, and also compared with sweet corn seeds (Zea mays L.) and sugarcane stems (Saccharum officinarum L.). The data was then validated for its significance using t-Tests. The result shows that the lollipop plant grown in partial shade has the highest brix percentage (27.00±1.02%) compared to the rest and is significantly different statistically. The brix percentage of all samples combined for this lollipop plant (25.56±0.42%) also surpassed the sugarcane (15.33±0.36%) and sweet corn (12.67±0.47%) and was significantly different statistically.

Tree crown traits and planting context contribute to reducing urban heat

Urban warming affects many millions of city dwellers worldwide. The current study evaluated the extent to which trees reduce air and surface temperatures in urban settings across Greater Sydney, Australia. Summertime air and surface temperatures were measured directly in the shade of 470 individual trees planted in three contrasting contexts (parks, nature strips, asphalt) and compared with temperatures in paired adjacent areas receiving full sunlight. Differences between shade and sunlit temperatures were evaluated against measured morphological traits (leaf area index [LAI], clear stem height, crown depth, height and diameter at breast height) for all trees. On average, tree shade reduced mean and maximum air temperatures by 1.1 °C and 3.7 °C, respectively. Temperatures of standardised reference surfaces (black and white tiles and artificial grass) in tree shade were up to 45 °C lower compared to full-sun exposure, and were also lower in parks and nature strips compared to asphalt settings. The surface temperature of shaded natural grass was cooler compared to sunlit natural grass, although this difference did not vary between nature strip and park settings. The magnitude of air and surface temperature reductions due to tree shade was significantly, positively related to tree-level LAI and these relationships were stronger in asphalt and park contexts compared to nature strips. These findings can inform decisions made by urban managers and planners around the selection of tree characteristics to enhance cooling benefits in different contexts, as an important step towards more liveable and resilient cities.

COULD FULL SUN EXPOSURE REPRESENT PHYSIOLOGICAL ADVANTAGES FOR CRIOLLO COCOA CULTIVATION?

In Venezuela, the physiological performance of adult cocoa trees under full sun exposure is unknown. The long-term effect of high photon flux density (PFD) on leaf water potential (), leaf area index (LAI), gas exchange, photochemical activity of PSII, and photosynthetic pigment content in adult cocoa trees of Ocumare 61 (OC-61) was evaluated, in order to know if OC-61 could have a good photosynthetic performance in plants grown in full sun (E) or if on the contrary there is a physiological disadvantage compared to those grown in shade (S), self-shaded leaves were also evaluated in each condition (E+A and S+A). The OC-61 clone grown in E showed significant changes in some physiological traits: lower , lower IAF, higher rates of photosynthesis (A) and water use efficiency (WUE), lower intercellular CO2 concentration (Ci) and lower total chlorophyll, and carotenoid content. An increase in electron transport rate, PSII quantum efficiency, photochemical and non-photochemical extinction coefficient was found that would partially explain the higher A's in E; there was no decrease in maximum quantum efficiency indicating the absence of photoinhibition. Clone OC-61 is a shade tolerant crop; however, the results indicate that it can be acclimatized to high sun exposure without damage to PSII functioning, which could represent a physiological advantage for clone OC-61 grown in the study area.

Growth response of Echinacea purpurea (L) Moench to biochar types and hormone doses

Purple Cone Flower (Echinacea purpurea) is one of the introduced medicinal plants originating from America which has its native habitat growing in subtropical countries with optimal growth conditions of low temperature and full sun exposure. Problems that occur in climate change between subtropics and tropics, especially in Indonesia will have an impact on the less than optimal growth and development of plants so that it will reduce the production and quality of ekinase yields. One way to improve ekinase can suitable in Indonesia (especially in the lowlands) is by adding biochar as a soil enhancer and hormones. The aims to study the interaction between the addition of biochar and the level of hormone dose on the growth rate of ekinase. The research method used a Split-Plot Completely Randomized Block Design. The results show the interaction between the type of biochar and hormone dose. The best results were shown in the treatment of giving husk charcoal and 6 ml/L hormones of 27.67 cm for plant height and 89.67 cm2 for leaf area. The formation of the highest number of leaves was 26 in the treatment of husk charcoal and hormone 2 ml/L. The best results were wood charcoal and hormone treatment 6 ml/L of 0.1467 for the rate of photosynthesis and 0.02937 for the rate of transpiration. Treatment with a dose of 6 ml/L hormone can optimize the growth rate of ekinase.

Effect of the Silvopastoral System on the Thermal Comfort of Lambs in a Subtropical Climate: A Preliminary Study

The silvopastoral system has the potential to alleviate the negative impacts of heat stress on livestock. Through a preliminary study, we assessed the thermal environment experienced by hair coat lambs, as well as the impacts on their bio-thermal and behavioural responses, when either kept in either the silvopastoral system, or exposed to full sun. Twelve hair coat lambs (Dorper × Santa Ines) were randomly assigned to a silvopastoral system or full sun exposure during the summer (from January to February 2017). Parameters, including air temperature, black globe temperature, relative humidity, wind speed, and ground surface temperature, were measured daily for both thermal environments. From 14:00 to 16:00, lambs kept in silvopastoral areas experienced lower levels of air temperature, radiant heat load, and ground surface temperature. Consequently, they had a lower hair coat surface and lower body rectal temperatures. Lambs exposed to a shaded environment spent more time grazing and walking, and less time standing at rest. In conclusion, lambs kept in a silvopastoral system experienced lower levels of radiant heat load and ground surface temperature. In addition, the animals showed a reduced requirement for evaporative cooling and expressed behaviours that indicated a comfortable thermal environment.

Species-specific performance and trade-off between growth and survival in the early-successional light-demanding group

We investigated if high irradiance imposes stress conditions and differently affects the performance of species from the early-successional light-demanding group and if the costs associated with plasticity underlie the trade-off between growth and survival. Survival, growth, chlorophyll a fluorescence, and carbon stable isotopic ratio (&delta;13C) were measured in seedlings of four tree species in a restoration area in the Atlantic Forest under full-sun exposure and partial shading treatments. The maximal quantum yield of PSII indicated stress conditions mainly in the full-sun exposure treatment (values from 0.72 to 0.81). The &delta;13C ranged from -31.9 to -30.4&permil;, but did not differ between treatments for three species, suggesting that C assimilation in initial restoration conditions is stressful even in shade. The survival scaled negatively with growth and plasticity adjustments. We conclude that early-successional species do not form a homogenous species group because they differ in functional responses to stress, and phenotypic plasticity, with these variations showing a strong link with the trade-off between growth and survival. This information should be taken into account for species selection in restoration programs.

Effect of Shading and Mowing on the Growth of Indonesia’s Native Zoysia grass in Silty Clay Soil

&lt;p&gt;In general, turfgrass grows well and forms high quality turf under full sun exposure. It is very difficult, however, to grow a warm season turfgrass under shaded condition. Zoysia grass is a popular warm season grass that commonly grow under full sun exposure condition. There are limited information regarding the growth response and turf quality of zoysia grass when grown under shaded condition. This study aims to observe the growth and quality of various zoysia grass local cultivars at different shading intensities and different mowing. This research was carried out using 10 zoysia grass cultivars planted in the rice fields’ vertisol clay with randomized complete block design. The shading used were control, shade-nets with 25% and 65% hole densities. Zoysia grass was fertilized using NPK; 4:1:3 and mowed three times. The results showed that plants without shade, 25% and 65% received on average solar irradiance of 25,141; 12,456 and 3,727 lux. The increase in shade level decreased the shoot fresh weight, dry weight, root dry weight and the plant height. Shading and frequent mowing effected the plant height. Mowing has more effect on plant height in 25% shading than in 65% shading. The increase in shading, in mowed grass showed increased plant height and decreased plant dry weight. Mowing three times can reduce plant height in all shades. The grasses under 25% shading resulted the highest plant dry weight; whereas and shading 65% resulted the lowest. Plant dry weight and uniformity of turf were affected by the cultivars.&lt;/p&gt;

Atenuación de la temperatura y radiación UV de la vegetación en entornos urbanos de ciudades ribereñas y su demanda hídrica.

Introducción. Este trabajo de investigación se realizó en la Ciudad de Honda, Colombia. Identificó el efecto de la sombra de los árboles en la atenuación de la temperatura, humedad relativa, temperatura de superficie del suelo, radiación solar y ultravioleta (UV) y determinó requerimientos de agua para la vegetación arbórea. Metodología. Se tomaron datos de temperatura del aire y de superficie de suelo, humedad relativa del aire, radiaciones solares y UV bajo la sombra de árboles y a plena exposición. Resultados. Se encontró que la temperatura del aire osciló entre 50ºC a plena exposición solar y 41ºC bajo sombra. La temperatura de superficie presentó a plena exposición solar valores de 66.8ºC y 42.6ºC bajo sombra. La variación de la radiación solar registrada ofreció un valor de 17.13 mW/cm2 a plena exposición solar y 1.69 mW/cm2 bajo sombra. La radiación UV presentó valores de 8 a plena exposición solar y 5 bajo sombra. La demanda hídrica por planta/día varió entre 5 y más de 500 litros, siendo la demanda diaria cercana a 2500 m3 . Conclusiones. En la ciudad no se realiza riego a los árboles, lo que conduce a que se produzca un déficit hídrico evidenciado por la pérdida de follaje ocasionando mínimas atenuaciones a la radiación UV. Las especies más relevantes respecto a la sombra son almendro (Terminalia cattapa), Pallandé (Pitecellobium dulce), naranjuelo (Capparis odoratissima), guayacán carrapo (Bulnesia carrapo), chirlobirlo (Tecoma stands), cumulá (Aspidosperma polyneuron) y mango (Manguifera indica). Los árboles pueden generar un buen servicio ecosistémico por la sombra, este servicio está mediado por la selección de la especie y el manejo de que son objeto los árboles.

Is temperature preference in the laboratory ecologically relevant for the field? The case of Drosophila nigrosparsa

Ectotherms are sensitive to temperature change, and predictions about a species' vulnerability to thermal change require an understanding of its thermal responses. The preferred temperature in laboratory assays is a widely used measure commonly taken as an indicator of the temperature at which ectotherms' physiological functions are optimised. The ecological relevance of laboratory-measured temperature preference has been evaluated for vertebrate ectotherms but to our knowledge not for Drosophila. Here, we assessed the links between laboratory thermal preference and habitat temperature in the alpine fly Drosophila nigrosparsa. We found that (i) in the laboratory, D. nigrosparsa preferred a temperature of about 10 °C. In the field, (ii) macrohabitat temperatures ranged from 17 to 22 °C, and (iii) microhabitat temperatures exceeded those of the macrohabitat with up to 35 °C at full sun exposure. (iv) Isotope-tracked flies were localised, among others, at nearly the maximum temperature conditions measured in the microhabitats. (v) Operative environmental temperature models revealed that air temperature has the highest impact on the flies’ experienced temperature, followed by global solar radiation and wind. These findings highlight that the preferred temperature in the laboratory differed strongly from that in the field and that different approaches lead to different conclusions about the preferred and experienced temperatures.

Productive and qualitative parameters of four Physalis species cultivated under colored shade nets

Abstract The genus Physalis L. has great importance in the framework of Brazilian biodiversity especially in the Amazon region. The use of colored shading nets allow manipulating the light spectrum, and thus supplying the appropriate quantity and quality of light for each species and maximizing production. The purpose of this study was to evaluate the effects of shade nets on fruit production and qualitative parameters of four species belonging to genus Physalis. The experimental design was random blocks with a 4 x 5 factorial scheme, four species of Physalis (P. peruviana, P. pubescens, P. minima and P. ixocarpa) and four colors of shade nets (white, blue, red and black), besides the control treatment under full sun exposure. Fruits were collected weekly and evaluated for longitudinal and transversal diameter and biomass with and without a calyx. Finally the percentage of calyx biomass compared to the total fruit biomass, number of fruits per plant and production were determined. A differentiated response was found among the species regarding the coloring of the converter shade nets. Plants of P. peruviana had the best productive and qualitative parameters of fruits when cultivated in full sunlight or under white shade nets, P. pubescens and P. minima when cultivated in full sunlight or under white and blue shade nets, and P. ixocarpa under red or black shade nets.

A new species of the genus Vellozia (Velloziaceae) from Minas Gerais, Brazil, with comments on endemism, distribution and conservation

Vellozia fontellana is described as a new species from the Ibitipoca massif in Minas Gerais, Brazil. This heliophilous species has sometimes been identified as V. crinita in herbaria and recent literature, but is readily distinguished by morphology, anatomy and occurrence restricted to northward slopes exposed to full sun exposure. The original description of V. crinita, translated from Latin, is complemented by information gathered from our collections and observations in the type locality spanning the last three decades of field work.

Schoolyard Shade and Sun Exposure: Assessment of Personal Monitoring During Children's Physical Activity

Childhood exposure to ultraviolet radiation (UVR) is a major risk factor for the development of melanoma later in life. However, it is challenging to accurately determine personal outdoor exposure to UVR, specifically erythemally weighted UVR (UVEry ), due to technological constraints, variable time-activity patterns, and the influence of outdoor environmental design. To address this challenge, this study utilized mobile and stationary techniques to examine the UVEry exposures of 14 children in a schoolyard in Lubbock, TX, in spring 2016. The aims of the study were to examine the influence of artificial shade on personal UVEry exposures and to assess full sun exposure ratios (ERs) within the same playground microenvironment. On average, personal wrist dosimeters worn during play in the sun measured 18% of the total onsite UVEry measured by a stationary UV pyranometer. Shade was found to significantly reduce the personal UVEry exposures by 55%, UVB280-315 nm exposures by 91%, and the overall solar radiation by 84%. Substantial benefits can be garnered through focused design of children's recreational space to utilize shade-both natural and artificial-to reduce UVR exposures during play, and to extend safe outdoor stays. Finally, although the wrist is a practical location for a dosimeter, it often underestimates full exposures, particularly during physical activity.

Primary and Secondary Yield Losses Caused by Pests and Diseases: Assessment and Modeling in Coffee.

The assessment of crop yield losses is needed for the improvement of production systems that contribute to the incomes of rural families and food security worldwide. However, efforts to quantify yield losses and identify their causes are still limited, especially for perennial crops. Our objectives were to quantify primary yield losses (incurred in the current year of production) and secondary yield losses (resulting from negative impacts of the previous year) of coffee due to pests and diseases, and to identify the most important predictors of coffee yields and yield losses. We established an experimental coffee parcel with full-sun exposure that consisted of six treatments, which were defined as different sequences of pesticide applications. The trial lasted three years (2013–2015) and yield components, dead productive branches, and foliar pests and diseases were assessed as predictors of yield. First, we calculated yield losses by comparing actual yields of specific treatments with the estimated attainable yield obtained in plots which always had chemical protection. Second, we used structural equation modeling to identify the most important predictors. Results showed that pests and diseases led to high primary yield losses (26%) and even higher secondary yield losses (38%). We identified the fruiting nodes and the dead productive branches as the most important and useful predictors of yields and yield losses. These predictors could be added in existing mechanistic models of coffee, or can be used to develop new linear mixed models to estimate yield losses. Estimated yield losses can then be related to production factors to identify corrective actions that farmers can implement to reduce losses. The experimental and modeling approaches of this study could also be applied in other perennial crops to assess yield losses.

Identificación de bacterias solubilizadoras de fosfatos en un Andisol de la región cafetera colombiana

El fósforo es un elemento esencial para el cultivo de café, sin embargo la mayoría de los suelos en Colombia presentan niveles bajos de este nutriente. La presencia de microorganismos solubilizadores de fosfatos (MSF) es una de las estrategias para suplir su demanda, en ese sentido se aislaron 26 bacterias rizosféricas de Typic melanudans de Cajibío (Cauca, Colombia), en tres agroecosistemas: café sin sombra, café con sombra y relicto de bosque secundario, evaluándoles la eficiencia solubilizadora de P (ESF) en Ca-P, Al-P, Fe-P en medios Pikovskaya sólido y líquido, obteniendo la secuencia de solubilización Ca-P &gt; Al-P &gt; Fe-P. Los dos aislamientos bacterianos con mayor ESF se identificaron por extracción del ADN y análisis del gen 16S rRNA como Kocuria sp, y Bacillus subtilis. Posteriormente se cuantificaron e identificaron los ácidos orgánicos presentes en las tres fuentes de fosforo por HPLC, siendo ellos los ácidos cítrico, glucónico, D- y L-málico, D- y L-láctico con mayor presencia en Ca-P- Kocuria sp. En todas las condiciones, se observó que ocurrió acidificación de los medios, siendo más fuerte en Fe-P y Al-P.