Shading Intensity Research Articles

Intercropping wheat between walnut trees reduced yield and improved quality

AbstractAgroforestry is a common traditional practice in southern Xinjiang, northwest China. However, intercropping productivity has failed to meet expectations in many agroforestry systems as tree aged. Therefore, this study invested why this occurred. We chose walnut (Juglans regia L. Wen‐185) tree‐based agroforestry systems to investigate the influence of walnut tree shade intensity on the grain yield and quality of intercropped wheat (Triticum aestivum). This replicated study was conducted in Southern Xinjiang China in 2011 and 2012. Walnut tree canopy reduced understory photosynthetically active radiation, decreased photosynthetic rates of intercropped wheat, decreased grain yield, spike number, grains per spike, and thousand‐grain weight. However, grain protein and wet gluten contents were improved. Significant negative linear correlations were detected between grain yield and N content with walnut tree age, but significant positive correlations were found between protein and wet gluten contents with walnut tree age. Protein and wet gluten contents were negatively correlated with grain yield, and with thousand‐grain weight. In conclusion, although grain yield was significantly decreased, grain quality was enhanced in walnut tree‐based agroforestry systems. The competition for light between walnut trees and intercrops could be alleviated by pruning, selective felling, and wider tree spacing.

Pasture and animal production in silvopastoral and open pasture systems managed with crossbred dairy heifers

The objective of this study was to evaluate the pasture traits and performance of crossbreed dairy heifers in a silvopastoral system (SPS) and open pasture (OP) of Urochloa decumbens, after 14-years of management. In the SPS, an average reduction of 46% in the photosynthetically active radiation (PAR) was calculated in relation to the OP. Experimental design was a randomized complete block, with three replications and two treatments (SPS and OP), evaluated in two seasons (summer and autumn), during three years. The paddocks were managed under continuous stocking with Holstein × Gyr heifers. The herbage mass was greater in OP, but a greater leaf and lower dead material percentages were observed in the SPS. The OP had higher tiller population than SPS only in the first year. The herbage accumulation was higher in the OP during autumn; however during summer only a trend was observed. The crude protein content was greatest in SPS, while the fiber constituents and forage digestibility did not vary with system. The stocking rate was greater in OP in the second year and similar between systems in the other years. Average daily gains were similar between systems, regardless of season and experimental year, while the OP showed a greater gain per area in the third experimental year. Despite of the difference in some variables, after 14–16 years of establishment, it was observed only a small decrease in the animal productive per area in SPS in the last year, in relation to OP, which indicates a high resilience of SPS, even under intense shading.

Physiological and behavioural responses of sheep grazing in a tropical silvopastoral system

Context Integrating trees and pastures can provide benefits to grazing animals in warm climates, such as provision of shade during the excessive heat. Aim Our aim was to evaluate the effects of two arrangements of trees on grass production and behavioural, physiological and blood parameters of crossbred lambs grazing massai grass (Megathyrsus maximus) pastures in a tropical environment in São Paulo state, Brazil. Methods Two groups of 24 Santa Inês × Dorper male lambs (~90 days old, 24.0 ± 3.3 and 22.0 ± 2.4 kg bodyweight, respectively) were used in two growing seasons, stratified by initial bodyweight and randomly assigned to one of three treatments: unshaded massai grass (no shading, NS), moderate shading (MS), or intense shading (IS). Treatments MS and IS were established with single rows of eucalyptus trees at spacing 12 m or 6 m between rows and 2 m within rows, corresponding to 786 and 1190 trees/ha. Each growing season consisted of two grazing cycles of ~20 days each, when tester animals grazed simultaneously in a rotational stocking system with variable stocking rate. Behavioural observations were feeding, lying ruminating, standing ruminating, lying, standing still, searching for food, and other. Physiological measurements were rectal temperature, respiratory frequency and heart rate. Blood parameters included haemogram, acute-phase proteins and serum cortisol concentrations. Key results Animals under treatment IS spent more time (P < 0.05) lying, standing still and at other activities than animals under NS and MS. Moreover, they presented lower rectal temperature and respiratory and heart rates than animals under NS during the first growing season, which was the season with higher temperatures. Cortisol and acute-phase proteins were not affected by treatment. Conclusions When animals were exposed to sun, the silvopastoral system was efficient for avoiding heat stress; however, the density of trees reduced the forage mass. Implications The silvopastoral system is a viable alternative production system in warm climates to improve the welfare of sheep, but the density of trees must be considered so that it does not negatively influence the forage mass.

Pre- and postharvest factors affecting quality and safety of Pepper ( Piper nigrum L.)

Abstract The quality and safety of pepper ( Piper nigrum L.) are a function of crop management practices, harvest maturity, harvesting methods and subsequent handling after harvest, including storage conditions and processing methods. The review shows that volatile oil decreases with shade intensity (15–30%). Essential oil, oleoresin, piperine and monoterpenes (thujene, α-pinene, sabinene, limonene, α-phellandrene and linalool) increase with altitude, while β-caryophyllene and total phenol decrease with increase in altitude. Fermentation of ripe pepper fruits forms odorants (butanoic acid, 3-methylindole, and 4-methylphenol) attributing intense faecal/shed-like off-flavour white pepper powder. Low-drying temperature (≤56°C) and duration (≤3 hrs) lead to low bulk density (0.17 g/ml) and low moisture loss (31%). Excessive soaking of black peppercorns prior to mechanical decortication reduces volatile oil and increases moisture content and broken berries. Availability of heavy metals in grinding machines increases the level of heavy metals; Fe (69.8–1147 mg/kg), Pb (21.3–947 μg/kg) and V (64.1–1072 μg/kg) in pepper powder. Storing peppercorns along with other materials enhances cross-contamination of heavy metals; Pb, Cd and Cr. High moisture content (>13%) and farmers’ unawareness resulted in high (2200 to >30000 cfu/g) mycotoxins contamination. Environmental and industrial pollutants such as plasticizers, bisphenol A, polycyclic aromatic hydrocarbons and pesticides are also pepper contaminants of high merit. Radiofrequency pasteurization, vacuum-assisted steaming, ethylene oxide fumigation, atmospheric pressure plasma, dry heat sterilization, gamma-irradiation and ultraviolet-C light treatments are among strategies to enhance the quality and safety of pepper. More precautions also have to be taken to regulate the shade, drying temperature and duration, soaking duration, hygienic processing and storage in order to retain quality, minimize the risk of microbial or chemical contaminations and comply with standards.

The population of Aconitum lasiostomum RCHB. (Ranunculaceae) in the right bank of the Middle Dnieper region: state and argumentation of protection

ntroduction. Aconitum lasiostomum has a sporadic distribution in Ukraine and is a rare species for most European countries. In terms of systematics, it belongs within the number of numerous morphologically and phytocenotically similar species of a section Lycoctonum DC. or is considered as part of an aggregate species Aconitum lycoctonum agg., which is nominal for the species of this section of the genus. Populations are scanty and susceptible to a range of ecological provide enough protection and require the reconsideration and systematization of the efforts aimed for Purpose. To assess the modern state of the population of Aconitum lasiostomum in the right bank of the Middle Dnieper region and to reason the raising of its protection status. 202187Methods. We identified and studied the new growth site of Aconitum lasiostomum in May-July 2020 inThe districts with an area of 10 x 10 m were planted within the natural borders of the phytocoenoses in the habitats of Aconitum lasiostomum. The habitResults. The previously unknown population of the endemic of Eastern Europe -Aconitum lasiostomum was described. The inclination of localities to the moderately illuminated growth sites -type was elucidated. The parameters of the Aconitum lasiostomum population were described. Total number about 100 specimens. Arrangement in clusters of 7-35 specimens of various ages. Percentage of generative individuals 38.4%. Under the intense shading, the percentage of generativeindividuals decreases to 3-4%. Maximum height of generative specimens at the beginning of flowering 62-120 cm. It has been found that Aconitum lasiostomum has a rare character of distribution in the right bank of the Middle Dnieper and other regions ofUkraine. The populations are organized in the conjunction with moist and fresh, middle-and rich edaphotopes under the broadleaf forests (alliances Alnion incana Pawlowski et al.1928 & Carpinion betuli Issler 1931). Obvious is the rather narrow range of coenotical conditions, which are sufficient for its growth and for the reproduction of the populations within the floral aggregations of the class Carpino-Fagetea sylvaticae Jakucs ex Passarge 1968. Originality. The first description of the population of Aconitum lasiostonum in the right bank and the main risks for the populations were determined. The increase of the sozological status of the species in Ukraine was justified. Conclusion. The previously unknown habitat of Aconitum lasiostonum within the communities, which are protected by the Resolution 4 of the Bern Convention, was elucidated. These communities are proposed to be protected within the Emeraldtall-It was determined, that the population of Aconitum lasiostonum is comparably numerous and diverse in age. Most of the loci with a high number of specimens are inclined to better illuminated growth sites. Aconitum lasiostonum allows us to claim the necessity of increasing the nature-preserving status of the species and including it in the Red Book of Ukraine. Keywords: Aconitum lasiostomum; population; nature preserving status; regionally rare species; rare biotopes

Effect of shading screens on the production and quality of ‘Smooth Cayenne’ pineapple

ABSTRACT In pineapple cultivation, it is common to cover the fruit with newspaper, in order to avoid scalding caused by sunburn. However, the scarcity of material and the large labor force required have led to the search of control alternatives. This study aimed to evaluate the use of shading screens in the production and quality of ‘Smooth Cayenne’ pineapple. A randomized blocks experimental design was used, with five treatments (fruits covered with newspaper and plants covered with screens with 35, 40, 50 and 80 % of shading), four replicates and two seasons (summer and winter). In the summer, the use of screens with 50 % of shading provided average gains of 22 and 39 % of total and commercial mass of crowned fruits per plant and gains of 22 and 40 % of total and commercial yield per hectare, respectively. The gradual increase in shading intensity resulted in a decrease in the qualitative attributes of the fruits, when compared to covering the fruits with newspaper. Screens with up to 50 % of shading can replace newspaper when covering the fruits to avoid scalding.

Coffee Berry Borer, <i>Hypothenemus hampei</i> (Ferrari) (Coleoptera: Scolytidae): A Challenging Coffee Productions and Future Prospects

Coffee is the major commodity legally traded in the world from agricultural productions. Even though, it’s economically important, its production and productivity is challenged by many factors, of which insect pests are the major. Among insect pests, coffee berry borer is the most challenging insect pest of coffee throughout the globe. It is the most important biotic constraints for commercial coffee production worldwide and major concern in eastern Africa. The infestations start when the adult females bore the berry and deposit eggs inside it. Hatched larvae start to feed on the inside the berry, which leads the reduction of yield and quality of the marketable product. On the other hand, almost all the lifecycle of the insect carried out inside the coffee berry and its cryptic nature, making it diffcult to control. Additionally, global warming is particularly important for coffee because of its influence on occurrence of pests which often diminish production and quality of coffee. Increasing infestation of coffee berry borer and their management have significantly constrained economical production of coffee. The infestation of the pest is highly influenced by altitude, coffee production system, agroforestry practices, shade intensity levels and the natural enemies’ diversity and populations. Many management options like cultural, insecticides, microbial and traps showed promising results under field conditions. But, using these options solely is unsustainable and ineffective for long term solutions. Then development of integrated management option for coffee berry borer is an issue in the future. And the compatibility of the promised options along with their application sequence also needs focus. The paper reviewed and identifies the research efforts should focus to increase the successfully developing an effective coffee berry borer management methods.

DIFFERENT SHADING INTENSITIES INTERFERE WITH THE GROWTH OF Myrocarpus frondosus ALLEMÃO SEEDLINGS IN THE NURSERY?

Native tree species present different responses depending on their adaptability to varying degrees of sunlight. The objective of this study was to evaluate the growth of Myrocarpus frondosus seedlings under different shade conditions in a nursery. The experimental design included randomized blocks in a factorial scheme, corresponding to treatments of full sun (0%), or one of three shading intensities (30%, 50%, and 70%), with evaluation times of 30, 90, 150, 210, 270, 330, and 390 days after emergence – d.a.e. The evaluation of the morphological attributes height (H) and stem diameter (SD) were determined every 60 days, and H/SD ratio were calculated. At 390 d.a.e, the following attributes were evaluated: aerial dry matter, (ADM), root dry matter (RDM), total dry matter, (TDM), Dickson quality index (DQI), leaf area (LA), root volume (RV), and root length. The pigment contents of chlorophyll a, chlorophyll b, and chlorophyll a/b ratio were also identified, along with carotenoid content, maximum quantum yield PSII (Fv/Fm), and electron transport rate (ETR). Myrocarpus frondosus requires shading in its initial stage of growth, at an ideal intensity of 50% or 70% for producing seedlings.

Effects on Different Shading Intensity on the Morphology and Physiology of Stenotaphrum helferi Accessions with Significant Di- fferences in Shade Tolerance

Effects on Different Shading Intensity on the Morphology and Physiology of Stenotaphrum helferi Accessions with Significant Di- fferences in Shade Tolerance

PENGARUH PEMBERIAN BERBAGAI TINGKATAN KOMBINASI PERLAKUAN NAUNGAN TERHADAP PERTUMBUHAN ANAKAN KEMIRI (Aleurites moluccana L.Willd)

This research aims to calculate life percentage on every treatment and analyze the growth of Kemiri (Aleurites moluccana L. Willd) seedlings to the various interaction between shade or light intensity. The variable of seedling growth includes height, diameter and sum of leaves. This research was conducted in open land area around farms and plantations with flat slope conditions in Padang Anyar roads, Tungkaran, RT 04, RW 02, South Borneo Province for 3 month. The data was analized using factorial Completely Randomized Design (CRD) with 4 treatment. Each replication consists of five sample and every treatment was repeated trhree times so that 60 seeds are needed (4x5x3). The result showed the life percentage of seedlings on every treatment was 100%. Growth under shade shows a significant effect on height of seedling, a very significant effect on diameter of seedling, and not give significant effect for sum leaves, known that 50% shade the best give effect to average response toward the increase of tall was 43,73 cm, stem diameter was 0,73 cm and sum of leaves was 13,8 leaves). Keywords: Growth; Kemiri; Shade

Influence of shade intensity on growth, biomass allocation, yield and quality of pineapple in mango-based intercropping system

Fruit tree-based intercropping system is commonly practiced in India; however, optimization of light environment for intercrops is essentially required to enhance their productivity. Influence of three shade intensities were examined on growth, biomass allocation pattern, leaf chlorophyll content, nutrient uptake, fruit yield and quality of pineapple in mango-based intercropping system. Compared to the monoculture pineapple system (LE0), the mean shade intensity under LE1, LE2 and LE3 were 23.8 %, 48.6 % and 73.3 %, respectively, whereas the mean PAR availability was 76.2 %, 51.4 % and 26.7 %, respectively. Significantly higher absolute growth rate (AGR), crop growth rate (CGR) and relative growth rate (RGR) was recorded under medium shade intensity (LE2). Dry matter accumulation was significantly high under LE2 followed by LE3. The biomass accumulation was significantly high in leaf followed by fruit and stem, whereas root system exhibited minimum biomass accumulation. Biomass of leaf and crown decreased with the plant biomass, whereas the biomass of fruit, stem and sucker increased. Contents of Chl a, Chl b and Chl a + b increased with the shade intensity and were found maximum under LE3. A gradual increase in N and P contents were observed in the leaves of pineapple with the reduction in PAR transmittance. However, the K content was relatively high under LE2. Increased fruit yield, fruit weight and fruit/crown ratio were recorded under moderate shade intensity (LE2). Total soluble solids and sugar content marginally decreased with the reduction in light intensity, whereas titratable acidity increased. Sunburn intensity significantly reduced under LE2 and LE3. Path analysis studies indicated that plant biomass was that most important predictor for fruit yield in pineapple. Our findings demonstrate that in eastern tropical region of India pineapple may be cultivated as an intercrop with ∼50 % shade intensity since the performance of crop is significantly affected under monoculture system.

Irradiated foxtail millet (Setaria italica (L.) P.Beauv): agronomic and physiological performances under low light intensity

The research was carried out to study the agronomic and physiological performances of gamma rays Irradiated Foxtail Millet (IFM) under low light intensity as an effort to obtain a shade-tolerant mutant. The experiment was performed in a Randomized Complete Block Design (RCBD) with two factors. The first factor was shading intensities, whereas the second factor was foxtail millet mutants resulting from gamma rays irradiation. The observation was performed on agronomic and physiological parameters, including plant growth, chlorophyll content (CC), photosynthesis rate (PR), and panicle production (PP). The result of this study showed that low light intensity decreased CC and PR values. The statistical analysis showed that CC value in 50% shading (33.02SPAD) was significantly different, with 0% shading (47.56 SPAD). Accordingly to this result, the PR value at 50% shading (7.112μmolm−2s−1) presented a significant difference as compared to 0% shading (19.379μmolm−2s−1). Observations on the plant height of GM 75.16 showed no significant difference with the control plants. Similarly, the result of PP on GM75.16 (17.03g) was not significantly different as compared to the control (16.24 g) and GM75.14 (14.10g). Therefore, GM 75.16was identified as a shade-tolerant mutant due to its ability to sustain the growth and development under low light intensity.

The chlorophyll contents and growth performances of West Java (Indonesia) jobtears (Coix lacryma-jobi) accessions under low light intensity conditions

Abstract. Juhaeti T, Setyowati N, Syarif F. 2020. The chlorophyll contents and growth performances of West Java (Indonesia) jobtears (Coix lacryma-jobi) accessions under low light intensity conditions. Biodiversitas 21: 5178-5185. The research was carried out to study the shading tolerance of five jobtears (Coix lacryma-jobi L) accession collected from Bandung, Kuningan, Garut, Sukabumi, and Sumedang West Java Indonesia. The existence of shade-tolerant jobtears was important to increasing its cultivation for food diversification effort. The research was conducted in the Botany Division, Research Center for Biology, Indonesian Institute of Sciences. The experimental design was a Randomized Complete Block Design with two factors. The first factors were 0%, 25%, 50%, and 75% shading intensity. The second factors were five West Java jobtears accession, namely Bandung, Kuningan, Garut, Sukabumi, and Sumedang accession. The shading intensity set up artificially by the black plastic net. Jobtears seeds planted on planting beds on 70x100 planting distance. The variable observed included microclimate, plant growth, leaf chlorophyll content, and grain production. The result indicated that jobtears accession showed differences in growth and production characters. Low light intensity significantly affected plant growth and production. The plant height, leaf number, and chlorophyll content variables increased until 50% shading intensity and then decreased by 75% shading. Plant production decreased by the increased of shading intensity. The Bandung and Garut accessions can be determined as a potential low-light tolerant accession due to its better growth and production compared with others and the lowest percentage of decreased production. For further research, the Garut and Bandung accession can be used as a genetic biodiversity source for shading tolerance breeding efforts.

Impacts of shading on seedling growth and mineral accumulation in Paeonia lactiflora

Shading is one of the important strategies to protect seedlings of Paeonia lactiflora. The effects of shading treatments on seedling growth and mineral accumulation of Duolun P. lactiflora were investigated in a greenhouse experiment to provide guidance for P. lactiflora cultivation. One week after emergence, seedlings were treated with 20%, 40%, 60% or 80% shading for two months, with no-shading as the control (CK). The results showed that shading treatments significantly increased plant height by 19.9%, 31.1%, 52.9%, and 63.7%, respectively. However, shading significantly reduced the root mass ratio and root to shoot ratio by 21.5%, 23.6%, 29.2%, 41.8% and 40.6%, 44.0%, 50.9%, 63.2%, respectively. Moreover, 40%, 60% and 80% shading significantly increased specific leaf area by 77.0%, 84.1% and 65.2%, and significantly increased chlorophyll content by 92.3%, 128.7%, 98.1%, and increased carotenoid content by 86.9%, 113.1% and 90.5%, respectively. The treatments of 40%, 60%, and 80% shading significantly decreased root biomass by 61.4%, 74.3% and 78.6%, respectively. Compared with CK, 20%, 40% and 80% shading, the 60% shading treatment increased root phosphorus content by 245.7%, 65.9%, 40.5% and 10.3%, increased potassium content by 102.9%, 131.7%, 57.0%, 63.3% and magnesium content by 131.3%, 55.1%, 40.4%, 7.7%, respectively. 60% shading was an appropriate shading intensity for P. lactiflora seedling cultivation based on local conditions in Duolun.

On the state of the ground cover of shaded areas in urban landscaping objects

It has been established that in municipal forestry of Stavropol (streets, squares, boulevards, parks) mixed plantations of broad-leaved tree species Tilia cordata Mill., Acer pseudoplatanus L., A. platanoides L., Aesculus hippocastanum L., Fraxinus excelsior L., Quercus robur L., prevail, which increases the shading conditions for lawns arranged under their canopy. With sparse and single-row planting of trees, lawn grass is in conditions of temporary shading and does not significantly suffer (lawns of good and satisfactory quality). In places with multi-row and group placement of tree plantations, the grass of lawns is in conditions of both temporary and permanent shading and is thinned up to 40–60 %, the relative amount of sunlight (RAS) is 2.1–9.2 % (mediocre and poor lawns). In conditions of constant intensive shading with a RAS of 0.6–2.6 %, turf grasses completely fall out, a dead cover forms, which reduces the quality of greening. Usually sparse grass are sown with fast-growing turf grasses annually. The issue of turfing of the shaded areas of parks with local forest grasses Brachypodium sylvaticum (Huds.) P. Beauv., Dactylis polygama Horvat., Festuca gigantea (L.) Vill., Poa nemoralis L. (RAS 2.1–5.8 %) and sedge Carex divulsa Stokes, (RAS 1.0–4.2 %) and the conservation of forest herbaceous cenoses is discussed. In shady parks, the use of ground cover introduced species Vinca minor L., Hedera helix L, and the herbaceous perennial Helleborus caucasicus A. Braun (RAS 1.2–7.4 %) is promising.

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

<p>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.</p>

Photosynthetic base of reduced grain yield by shading stress during the early reproductive stage of two wheat cultivars

The young microspore (YM) stage is the most sensitive period for wheat grain formation to abiotic stress. Shading stress during YM stage reduces grain yield mainly due to grain number decrease. However, the photosynthetic base for grain number decrease is still unclear. In this study, 100% (control), 40% (S1), and 10% (S2) of natural light were applied for 1, 3, 5, and 7 days (D1, D3, D5 and D7) during YM stage of two wheat cultivars (Henong825, Kenong9204). The results showed that grain number in Henong825 and Kenong9204 was reduced by − 3.6 to 33.3% and 14.2–72.7%, respectively. The leaf photosynthetic rate (Pn) in Henong825 and Kenong9204 was deducted by 4.5–93.9% and 26.4–99.0%. Under S1–D1, the leaf Pn of Henong825 reducing was mainly due to the reduction of light intensity. With shading intensity and duration increasing, the reasons for leaf Pn decrease were the low light intensity, the low Gs (stomatal conductance) and chlorophyll content, the damage of ultrastructure of chloroplast and photosynthetic system. Under S2–D7, the chlorophyll content, Fv/Fm (maximal photochemical efficiency of photosystem II) and Jmax (maximum electron transport) were reduced by 19.6%, 5.2% and 28.8% in Henong825, and by 29.9%, 7.8% and 33.1% in Kenong9204. After shading removal, the leaf Pn of Kenong9204 under D5 and D7 could not reach to the level of CK. This study indicated that the reduction of leaf Pn was mainly due to the low light intensity under short shading duration (shorter than 3 days), and due to low light intensity and damage of the leaf photosynthetic system under longer shading duration (longer than 5 days), especially for Kenong9204 (shade-sensitive cultivar).

SHADING AS A DETERMINANT FACTOR FOR THE SURVIVAL AND GROWTH OF Cabralea canjerana IN SOUTHERN BRAZIL

Plantations with native tree species, which emphasize biodiversity conservation, may not succeed because of a lack of forestry knowledge about the native species. Cabralea canjerana is an important tree species, which is rarely present in area restoration programs because of the difficulty in establishing it in plantations. Despite this, the species is also known for its adaptation to different light conditions. Therefore, this research sought to answer: a) What is the appropriate light level for the initial establishment of Cabralea canjerana seedlings in the field? b) Does seasonality influence the morphological and physiological attributes of Cabralea canjerana plants? The treatments used were: four shade intensities (0, 18, 50 and 70%) and two seasonal periods (spring-summer and autumn-winter). Survival was evaluated at 30 and 360 days after planting, while the morphological and physiological attributes were evaluated at 180 (spring-summer) and 360 (autumn-winter) days after planting. We suggest that Cabralea canjerana be classified as a moderately shade-tolerant species, considering that even in a region with four well-defined seasons, like the one in the present study, its mortality rate was high in full sun, a fact that is corroborated by the morphological and physiological parameters. The planting of Cabralea canjerana seedlings in full sunlight is not appropriate because it causes low seedling survival. It is recommended that planting be carried out under 50% shading. Seasonality influenced the morphological and physiological attributes of Cabralea canjerana plants.

The fluorescence of resin-based composites: An analysis after ten years of aging.

The long-term preservation of fluorescence qualities of resin-based composite (RBC) restorations is an absolute condition for the implementation of the fluorescence-aided identification technique (FIT) in dentistry and forensic medicine. Therefore, this study assessed the fluorescence of 244 color shades of 16 commercially available RBC brands with a monochromator-based multimode microplate reader. The specimens were stored in the dark at room temperature and reassessed ten years after the initial investigation. The mean intensity of the fluorescence maxima decreased from (31,030±936) RFU to (22,027±632) RFU. Linear regression resulted in r2=0.972 and a slope=0.701±0.005. The fluorescence intensity of the tested RBCs dropped to about 70% of the initial intensity independent of the brand, color shade and initial fluorescence intensity. On the basis of this in vitro 10-year data set, we assume that in vivo RBC fluorescence is also suitable for the detection and differentiation of clinically aged RBC restorations by FIT.

Growth Response of Thunbergia grandiflora (Roxb. ex Rottler) Roxb. (Skyflower) on Shading and Anatomical Characteristics Under Various Soil Series

Thunbergia grandiflora Roxb. (Acanthaceae) or “skyflower” is an exotic species that was reported to be aggressively spreading out of control in the tropical and subtropical ecosystems. This study assessed the invasive characteristics of the species by analyzing its growth characteristics on varying shading intensity and soil series, as well as anatomical characteristics in varying soil series. Growth characteristics include the height and root collar diameter (RCD), while anatomical parameters include the thickness of all dermal, ground, and vascular tissues. Based on the results of the shading experiment, T. grandiflora grew significantly in terms of height and RCD under full light conditions (1784.75 lx). The species can survive intense light condition but is suppressed under partial to fully shaded treatments. In the soil series experiment, the highest growth and RCD were observed in the Luisiana soil series with strongly acidic soil (4.1 pH). The leaf and stem anatomical structures of T. grandiflora have the characteristics typical of invasive species that can adapt to certain harsh conditions. This includes the presence of dense non-glandular trichomes, cystolith, multi-layered collenchyma cells in the hypodermis, sclerenchymatous tissues, wider xylem pores, and closely pack parenchyma cells in the stem. Therefore, anatomical structures of this species suggest its ability as an invasive species. Consequently, the invasive characteristics can be suppressed by controlling the shade and soil conditions during the wildling stage of the species. The species can be bioinvasive and the extent may depend on the prevailing conditions in the site. However, further researches on the species’ root physiological and anatomical responses to other biotic and abiotic factors in the environment are recommended. Also, knowing the invasiveness of T. grandiflora will help us identify possible strategies to limit the spread of the species, including early detection of the occurrence of species, avoiding disturbance in the area, and identifying species as biocontrol.