Shading Nets Research Articles

Combined metabolome and transcriptome analyses reveal that growing under Red shade affects secondary metabolite content in Huangjinya green tea

Shading treatments impact the tea (Camellia sinensis L.) quality. The sunlight sensitive varieties can be grown under shading nets for better growth and secondary metabolite content. Here, we studied the responses of a sunlight sensitive green tea variety “Huangjinya” by growing under colored shading nets (red, yellow, blue, and black (75% and 95%) shading rates) to find out the most suitable color of the shading net. Red shading was the most promising treatment as it positively affected the weight and length of 100 one-bud-three leaves and reduced the degree and rate of new shoots burn compared to control (natural sunlight). We then explored the comparative metabolomic changes in response to red shading by using UPLC-ESI-MS/MS system. The amino acids and derivatives, flavonoids, and alkaloids were downaccumulated whereas lipids, organic acids, and lignans were upaccumulated in Red shade grown tea samples. The red shading nets caused a decreased catechin, epicatechin, dopamine, and L-tyramine contents but increased caffeine content. We then employed transcriptome sequencing to find key changes in expressions of related genes and pathways. Notably, key genes associated with the phenylpropanoid and flavonoid biosynthesis pathways exhibited complex regulation. These expression changes suggested a potential trend of polymerization or condensation of simple molecules like catechin or pelargonidin into larger molecules like glucoside or proanthocyanidins. Here, Red shading net triggered higher expression of genes enriched in lipid biosynthesis and jasmonic acid biosynthesis, suggesting an interplay of fatty acids and JA in improving tea performance. These findings contribute to the metabolic responses of Huangjinya tea to red shading nets which might have implications for flavor and health benefits. Our data provide a foundation for further exploration and optimization of cultivation practices for this unique tea variety.

Chemical Composition and Bioactivity of Dill Seed (Anethum graveolens L.) Essential Oil from Plants Grown under Shading

This study determined the content and composition of dill seed (Anethum graveolens L.) essential oil under varying light conditions: non-shaded plants in open fields and plants covered with pearl shade nets (40% shade index). Essential oil was extracted using Clevenger hydrodistillation. The essential oil content was 4.63% for non-shaded plants and 4.81% for shaded plants. GC/MS analysis revealed twenty-one and twenty-two components in dill seed from non-shaded and shaded plants, respectively. The terpenic fraction of essential oil from non-shaded plants consisted mainly of oxygen-containing monoterpene derivatives (53.6%), with carvone (46.1%) as the primary component, followed by monoterpene hydrocarbons (46.4%), predominantly limonene (43.8%). Essential oil from shaded plants contained a higher content of carvone (49.8%) and a lower content of limonene (37.8%) compared to essential oil from non-shaded plants. Non-shaded plant essential oil exhibited stronger antioxidant activity (EC50 value: 26.04 mg mL−1) than shaded plant essential oil (54.23 mg mL−1). Dill seed essential oil showed the most potent antimicrobial activity (disc diffusion method) against Escherichia coli (inhibition zone: 15–18 mm). Shaded plants demonstrated a positive influence of essential oil against Klebsiella pneumoniae. Carvone and its derivatives, as the main components, hold significant potential in the food industry and alternative medicines. A practical implication of this study could be higher plant densities or intercropping of dill, as it thrives with minimal light.

Assessing the effect of artificial shading and saccharose sprays on the yield and fruit quality of cranberry (Vaccinium macrocarpon Aiton)

ABSTRACT A natural low fruit set is reported in cranberry. It is hypothesised that a carbohydrate shortage limits fruit set, and thus yield potential. We aimed to evaluate the effect of carbohydrate availability induced by shade and saccharose spraying during reproductive stages of ‘Stevens’ cranberry to identify critical periods for yield and juice quality (soluble solids, acidity, and colour). Two independent experiments were conducted. On five separate dates, artificial shade (90% shade nets) was imposed for two weeks. On the same dates, 417 kg ha−1 of saccharose was sprayed as a 10% w/v solution. Results showed that shading from full bloom to the beginning of the fruit set reduced fruit number and juice colour. In contrast, 10% saccharose spray increased yield by 22% compared to the control without compromising juice quality. Therefore, the period between the end of full bloom and the beginning of fruit growth is the most critical stage for ‘Stevens’ cranberry.

Impact of Shade Nets on Tomato Output and Quality in Temperate Region of Kashmir Valley

A field trial was conducted at Sher-e-Kashmir University of Agricultural Sciences and Technology, Kashmir, Shalimar Campus during 2020-21 to ascertain the impact of shade nets on tomato output and quality inside the protected structure. During the study, it was found that no significant difference was observed in average monthly temperature and relative humidity inside polyhouse with shade net and without shade net. Significant difference was recorded in yield and the light intensity. Highest average plant yield of (15.5 kg/plant) was found in polyhouse in which the plants were covered with shade net and lowest yield was observed (13 kg/plant) where plants were not covered with shade net inside the polyhouse during afternoon day time. It was also found that the tomatoes that were grown in shade nets showed good colour development and a glossy appearance as compared to plants grown under protected structures without shade net. No significant difference was observed in quality attributes viz. TSS, acidity and ascorbic acid by shade net. However, the higher TSS (7.1 oBrix), Acidity (0.77%) and Ascorbic acid (45.86 mg/100gm) was recorded in polyhouse without shade net as compared to polyhouse with shade net (6.7, 0.51 and 38.52) respectively. Thus, use of shade net brought improvement in yield and no significant improvement was observed in quality of tomato grown in temperate region of Kashmir valley. Also, the shade net application during winter duration of 2021-22 during evening/night hours led to increase in the temperature inside polyhouse.

Plant Growth, Fruit Yield, and Tomato Leaf Curl Disease of High Tunnel Organic Tomato Affected by Shade Net and Plastic Mulch Color

There is an increasing interest in producing organic tomatoes (Solanum lycopersicum) in high tunnels (HTs) in the southeast United States. HTs are unheated, passively cooled structures that allow tomato growers to harvest high-quality fruit out of season. However, excessive temperatures inside HTs may negatively impact tomato plant growth and fruit yield. Shade nets have been reported to reduce temperatures inside the HTs. Plastic mulch color has also significantly influenced plant growth and yield under high-temperature conditions. This study aimed to determine the effects of shade net color and plastic mulch color on plant growth, fruit yield, and incidence of tomato yellow leaf curl disease (TYLC) in ‘Red Snapper’ tomato grown in HTs under elevated temperatures (summer-fall) in southern Georgia, USA. Organic ‘Red Snapper’ tomato seedlings were transplanted in HTs in 2019 (Season 1) and 2020 (Season 2). The design was a split-plot randomized block where the main plots were externally mounted shade nets (black, silver, and unshaded; 30% shade factor), and the subplots were plastic mulches (black and white). Compared with black mulch, white mulch improved plant height and stem diameter but did not influence fruit yields. Shade nets reduced HT air temperature and root zone temperature (RZT) but did not affect plant height and stem diameter. The diminished photosynthetic photon flux density (PPFD) under the shade nets reduced marketable fruit yield. Thus, shade nets are not recommended once heat challenges do not limit HT tomato production in Georgia (after about mid-October). Shade nets and plastic mulch inconsistently affected TYLC incidence, severity, and area under the disease progress curve (AUDPC). Additional fruit yield reductions occurred due to TYLC because the incidence was 100% 6 weeks after transplanting. Preliminary insect data showed that shade net treatments had similar sweetpotato whitefly (Bemisia tabaci) numbers. The high TYLC incidence indicates that ‘Red Snapper’ may not be suitable for fall HT tomato production in the southeast United States. More research on shading and heat stress management in HT organic tomato production is necessary.

Production and quality of ornamental peppers cultivated under colored shade nets

The cultivation of ornamental peppers in places with high temperature and incidence of solar radiation limits the production and quality of plants and fruits. The colored shade nets were introduced and adopted, because they reduce the temperature and intensity of solar radiation, as well as, low cost and simple to handle. The aimed was to evaluate the production and quality of C. chinense and C. frutescens cultivated under colored shade nets. The experiment was developed in the Floriculture Sector of the Agronomy Department of the Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil from February to August 2021 in entirely randomized design.  C. chinense and C. frutescens were cultivated under red, pearl and aluminet nets with 35% shading and without net. At 150 days, production variables were quantified. The red net reduced the maximum temperature by at 4.1ºC and the pearl and aluminet nets reduced the minimum temperature by 3ºC. The maximum and minimum relative humidity was increased by 2.6 and 8.5%, respectively, by the red net. The pearl net obtained the lowest percentage of solar radiation incidence. Plant height was greater in the red and pearl nets, and C. frutescens. The diameter and stem fresh matter did not differ statistically between treatments. Root length was greater in the red and aluminet nets. The longitudinal and transverse canopy ratio was higher in C. chinense cultivated under the aluminet net. The number of leaves and leaves fresh matter was higher in pearl and aluminet net, and in C. frutescens, but leaves dry matter was higher in C. chinense. The number of flower buds and flowers, and flower buds dry matter was higher in C. chinense. The root fresh matter and dry matter was greater in C. chinese. The use of colored shade nets during the cultivation period effectively reduced temperature and light intensity. The aluminet net in association with C. chinense are recommended considering the compactness of height, pot coverage, greater number, shape and arrangement of fruits.

Creating a new yellow and blue combination transparent film for Panax ginseng C.A. Meyer growth based on orthogonal designs

Panax ginseng C.A. Meyer originates from old-growth forest environments, where the light intensity and spectrum reaching the forest bed are influenced by the canopy and humidity. In farmlands, suitable light intensity for cultivation is achieved by controlling the light transmission rate using shading nets, while light quality is regulated by a cover of yellow or blue transparent film. Such films have a light quality distinct from that produced by old-growth forests. Herein, a large composite film was developed by alternating small pieces of yellow and blue transparent film. An orthogonal array was used to evaluate the influence of the small transparent film area (STFA), yellow transparent film (YTF) number, and blue transparent film (BTF) number on the associated changes in ginseng in a range of fluorescence-, photosynthesis-, morphology-, and crop quality-related factors. Our results showed that light intensity was influenced primarily by STFA, which caused an overall decrease, while the light quality ratio was affected primarily by YTF number, which increased the proportion of red light and decreased that of blue light, with corresponding influence on different growth parameters. Based on these observations, an improved yellow and blue combination transparent film (YBCTF) with the following characteristics was established: STFA: 15 × 15 cm, YTF: two pieces, and BTF: three pieces. The improved YBCTF facilitated efficient light energy use by the plants, and led to an increase in leaf area, the per leaf photosynthetic rate, dry root weight, and the per root single ginsenoside yield. The findings present a relatively low-cost approach for optimising the light environment of ginseng cultivated in farmland and other crops in large-scale agricultural settings.

Monofilament Shading Nets Improved Water Use Efficiency on High-Temperature Days in Grapevines Subjected to Hyperarid Conditions

(1) Background: Table grapes are often subjected to thermal stress during the growing season, affecting their production. Shading nets utilization has been proposed as an alternative to face this problem, but there is little available information about their effectiveness in hyperarid conditions. INIA-G2 vines were covered with kristall-colored mesh of 8% shade, and their ecophysiological responses were compared to uncovered vines during the daily cycle of two days with contrasting thermic conditions. (2) Methods: Net assimilation rate (AN), stomatal conductance (gs), transpiration (E), instantaneous water use efficiency (WUE: AN E−1), stem water potential (Ψs), air temperature (Ta) and vapor-pressure deficit (DPV) were determined in daily cycles (from 06:00 to 20:00 hrs) on two thermally contrasting days (330 DOY at 29.4 °C and 345 DOY at 22.6 °C) on grapevines without water restriction. (3) Results: The Ψs was not affected by treatment and day of measurement; nevertheless, AN and gs were statistically lower during 330 than 345 DOY (31% and 44% decrease, respectively). The covered vines presented less restrictive climatic conditions in terms of DPV in both DOY, reaching higher WUE values at 10, 12 and 14 h, which was associated with a decrease in E. (4) Conclusions: These results suggest that the use of shading nets can be an interesting alternative to cope with high temperatures in viticulture, improving the water use efficiency of vines. These are the first published results about the viticultural performance of the INIA-G2 variety.

Covering young avocado ‘Hass’ trees with high-density shading nets during the winter mitigates frost damage and improves tree performance

Key messageCovering young ‘Hass’ trees with Silver 60% shading nets during cold winters mitigates frost damage and improves tree performance, apparently through a mechanism other than increasing nighttime air temperature.Avocado is a commercially important subtropical evergreen fruit tree. Severe frost may damage foliage, floral buds, flowers and fruit, thereby reducing avocado crop yield and restricting its geographical distribution and expansion. Shading nets are frequently used to protect agricultural crops from climate-related damage. To determine their ability to mitigate frost damage, Silver 60% shading nets were deployed over young ‘Hass’ trees during two consecutive winters and uncovered trees served as controls. Freezing and chilling temperatures occurred in the experimental orchard during the winter of each year, from December to March, reaching − 2.49 ℃ in January 2022. In the control, 93% of the examined floral buds were severely damaged compared to 4% in the Silver 60% trees. Damage to young vegetative shoots was assessed at 4.35 out of 5 in the control compared to 0.5 out of 5 in the Silver 60% trees. In both years, minimum air temperatures under the Silver 60% shading nets were similar to those of the control. Leaf-level photosynthetic photon flux density was ~ 60% lower under the shading nets. In most measurements, CO2-assimilation rate, stomatal conductance, ratio of variable to maximum fluorescence (Fv/Fm) and chlorophyll concentration in the leaves of the Silver 60% trees were higher than, or similar to the controls. Trunk diameter and flowering intensity of the Silver 60% trees were higher than for the control. These results indicate that covering young ‘Hass’ trees with Silver 60% shading nets during cold winters can mitigate frost damage and improve tree performance.

Influence of Different Colored Shade Nets on Micro Environmental Parameters and Pest Incidence of Various Ornamental Plants

A field experiment was carried out at Floriculture and Landscaping Block, College of Horticulture, Anantharajupeta during 2022 and 2023. to study the Influence of different colored shade nets on microenvironmental parameters of various ornamental plants. The experiment consists of 25 treatments with three replications which were laid out in FRBD. The treatments were formed with two factors viz. Factor I (Colour shade nets, Green (C1), White (C2), Black (C3), Red nets (C4) and Open (C5) condition and Factor II plants (Pandanus veitchii (P1), Epipremnum aureum (P2), Sansevieria trifasciata (P3), Aglaonema commutatum var. Redgold (P4), Rhoeo spathacea (P5) were taken. The results shown that the maximum temperature was under black net (32.43, 34.10 0C in first and second year respectively), maximum RH was under black net (88.09, 83.11 % in first and second year respectively), lowest canopy temperature was under shade nets than open. Maximum light intensity (653.21, 669.4 lux in first and second year respectively), average PAR values were maximum under white net (718.05 µmol m-2 s-1) in both years. Mealy bug incidence was maximum under black net in both years during the period of study

Simultaneous Effects of Shade Nets and Different Water Supplies for Mapping Multiple Physicochemical Traits of ‘Jonagold’ Apple: Insights from a High-Density Orchard in Iran

Simultaneous Effects of Shade Nets and Different Water Supplies for Mapping Multiple Physicochemical Traits of ‘Jonagold’ Apple: Insights from a High-Density Orchard in Iran

Production of American lettuce cultivars under different colored shade nets

Shading nets are used to reduce the amount of radiant energy reaching crops. The objective of the work was to compare the influence of black and red shading nets on the production of nine American lettuce cultivars in the Autumn period under the conditions of the Central Department of Paraguay. The experiment was carried out in the Experimental Field of the Departmental Agronomic Center (CAD) in the Municipality of Julián Augusto Saldívar. The treatments consisted of the combination of two types of shading netting (red with 35% shade and black with 35% shade) and nine cultivars of American lettuce (Julia, Dora, Angelina, Tainá, Sun Valley, Betty, Lucy Brown, Mara, and Serena) totaling 18 treatments. The experiment consisted in a complete randomized block design, arranged in split blocks 2×9 (the color of shading netting was considered the main plot, and the lettuce cultivars as the secondary plot) with four repetitions. Each experimental unit consisted of four crop rows with seven plants. Plant diameter, plant height, head diameter and height, commercial number of leaves per plant, fresh mass, and commercial productivity were evaluated. The data were subjected to analysis of variance, and when differences were found, the means were compared by the Scott-Knott test at 5% probability. The results indicate that using the red netting with the Serena and Dora cultivars provides greater fresh mass and commercial production.

Effects of black sun shade nets and humidity levels on cassava growth for mini-cutting propagation

This research presents the effects of black sun shade nets and humidity levels on cassava growth for mini-cutting propagation. The experiments were split-plots design with three replicates where two net shade covering treatments: one with 100% coverage using black sun shade net and the other with no covering as control were assigned in main plots and three humidity levels: 65-70%, 70-75%, and 75-80% to sub-plots. Data on shoot emergence rate, numbers of shoots per stem cutting, plant height, number of leaves and shoot diameter were measured. The obtained results suggested that the combination of 50% covering with black sun shade nets and maintaining a humidity level of 70-75% is effective for cassava multiplication Our findings may help in further strategy for the application in cassava rapid propagation

Differential performance of Dianella tasmanica and Pleomele reflexa under coloured shade nets

Cut greens are emerging as an important constituent of the floricultural industry as they add freshness and colour to floral designs. An experiment was conducted to evaluate the effect of different coloured shade nets (black, blue, green, red, white and no shade) at 50% shade intensity on growth and quality parameters of Dianella tasmanica and Pleomele reflexa. Both species significantly responded to the change in colour of shade nets. In D. tasmanica, maximum plant height (85.66 cm), stem diameter (8.63 mm) and leaf length (68.33 cm) were recorded under red shade net, while, plant spread (63.03 cm) and leaf breadth (4.06 cm) under black shade net, however, leaf thickness (0.57 cm) and vase life (24.33 days) under white shade net. In P. reflexa, maximum plant height (63.66 cm), stem diameter (9.76 mm), leaf length (17.50 cm), leaf thickness (0.93 cm) and SPAD index (60.10) were recorded under red shade net, whereas, plant spread (36.34 cm) and leaf breadth (3.00 cm) under black shade net, and vase life (25.66 days) under white shade net. Thus, red coloured shade nets could be preferred commercially for better performance of D. tasmanica and P. reflexa.

AGRONOMIC RESPONSE OF FOUR Dahlia pinnata Cav. (Asteraceae) VARIETIES IN THREE PRODUCTION ENVIRONMENTS

Flower cultivation has increased nationwide. Currently, species of the Dahlia genus (known colloquially as Dahlias) are grown for ornamental purposes, with central Mexico having the highest production rate. Due to its importance, we sought to evaluate the effect of three different methods of cultivation (shade net, greenhouse, and open field) on the growth and development of four dahlia varieties in Saltillo, Coahuila, Mexico. The experiment was carried out at the Horticulture Department of the Universidad Autónoma Agraria Antonio Narro. Tuberous roots of four D. pinnata varieties were sown directly into the soil and covered with mulch. The shade netting production environment proved to be the best in production, with the best results in plant height, stem diameter, number of leaves, and days to flowering. The highest-performing cultivar was the Antje variety. On the other hand, the Antje variety (cultivated under shade netting) had the longest flower stalks, the Boy Mick variety (cultivated in the greenhouse) had the heaviest flowers, and the Canby Centennial variety (cultivated in open field) had the flowers with the thickest stalks. The results show that Dahlias can be grown in northeastern Mexico because the area meets suitable conditions for crop development and production.

Morpho-physiological changes in oil palm (Elaeis guineensis Jacq.) tenera hybrid seedlings raised under different shade levels

Climatic conditions prevailing in oil palm growing states of India indicate the need for shade during primary stage of oil palm nursery for optimum growth and vigour of seedlings. Experiments were conducted to standardize the shade requirement based on growth/quality of oil palm seedlings in summer, rainy and winter seasons by providing 25%, 50% and 75% ultra violet stabilized high density poly ethylene (HDPE) shade nets. Results were found significant among the treatments for most of the growth parameters studied over the seasons. Highergrowth for key characters like seedling height, leaf area, collar girth and dry matter production were recorded at 75% shade level. Similarly, higher chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and inter cellular CO2 concentration were observed at 75% shade. Among the season, seedling growth was vigorous in rainy season followed by summer and winter seasons. Hence, provision of 75% shade found to be ideal for raising seedlings during primary stage of nursery in oil palm.

Estimation of genetic parameters and variability of various cayenne peppers under net shading

Abstract. Siahaan GF, Chozin MA, Syukur M, Ritonga AW. 2023. Estimation of genetic parameters and variability of various cayenne peppers under net shading. Biodiversitas 24: 5912-5919. The intercropping systems are important concerning the decreasing agricultural land and the increasing population. Chili could be planted as intercrops, but not all chili genotypes were adapted to low light-intensity stress. This study aims to determine the genetic diversity of cayenne pepper under 50% plastic net shade conditions based on morphological and agronomic traits. The study was conducted at the Cikabayan Experimental Field, Institut Pertanian Bogor, Dramaga, Bogor, from January to July 2021. The genetic material consisted of ten genotypes of cayenne pepper from Capsicum annuum L. and ten from Capsicum frustescens L.. Each genotype of chili was planted with three replications, so there were 60 experimental units. Each experimental unit consisted of six plants planted in an area of 1.5 m2. The shade used was a plastic net shade with a 50% shading level. The estimation of genetic parameters showed that leaf area, number of leaves, fruit weight, number of fruits, and yield per plant had a high genotypic coefficient of variation (GCV) and broad-sense heritability (Hbs). Cluster analysis resulted in two main clusters based on twelve chili growth and agronomic characters. All chili genotypes included in Cluster 1 were C. annuum chilies. On the other hand, all the chili genotypes in Cluster 2 were C. frutescens chilies except for the G19 genotype. Cayenne pepper in Cluster 2 had a higher number of leaves, plant height, stem diameter, leaf area, fruit diameter, pedicle length, fruit weight, number of fruits, and yield per plant than cayenne pepper in Cluster 1. The result of this study indicates that C. frutescens cayenne pepper has more potential to be planted under shading conditions and used in intercropping than C. annuum.

Colored Shading Nets Differentially Affect the Phytochemical Profile, Antioxidant Capacity, and Fruit Quality of Piquin Peppers (Capsicum annuum L. var. glabriusculum)

Piquin pepper fruits, a semi-domesticated wild pepper species highly valued in Mexico, currently face the threat of unsustainable harvesting practices that endanger the species. For this reason, it is necessary to establish sustainable agricultural practices for the cultivation of these peppers. Solar radiation, a critical determinant in crop production, plays a crucial role in plant development, influencing a spectrum of physiological and morphological processes, including the synthesis of phytochemicals. Our study evaluated the effect of light manipulation through colored shading nets on the phytochemical profile, antioxidant capacity, and fruit quality of semi-domesticated piquin peppers at two maturation stages: immature and mature (green and red fruits). Our hypothesis posits that these shading treatments may induce changes in these fruits’ phytochemical composition and antioxidant properties, as well as quality. Our results indicate that the shading treatments and maturity stage have significant on capsaicinoid and carotenoid levels, with the highest levels observed in mature fruits. Notably, red fruits grown under black shading treatments resulted in the highest capsaicinoid levels. Carotenoid levels were higher in the black shading treatment during the first cycle, while in the second cycle, the blue shading treatment showed elevated carotenoid levels, suggesting that high irradiance conditions could reduce carotenoid contents. Although no significant differences were observed among the treatments in green fruits, in red fruits, both black and blue treatments exhibited the highest total phenolic compounds in both production cycles. Furthermore, the antioxidant capacity revealed that red fruits exhibited higher antioxidant levels than green fruits. Color analysis showed that red fruits had higher chroma and hue angle values, indicating their brighter and more intense red color than green fruits. The morphological changes in fruit width, length, and weight can be attributed to shading treatments and maturation stages. These results indicate the potential of piquin peppers to act as rich sources of bioactive compounds, emphasizing the benefits of shading as an effective strategy to improve the quality and quantity of phytochemical compounds in piquin peppers. Our findings provide substantial insights into the intricate relationship between maturation, shading treatments, and phytochemical composition, offering a path to improve the nutritional value and quality of piquin peppers.

Phytochemical composition and antimicrobial activities of the essential oils from summer savory (Satureja hortensis L.) growing in shading condition

This study was conducted to investigate the effect of plant shading (covered by pearl shade nets with a 40% shade index or nonshading plants from open field) on the content and composition of essential oils extracted from summer savory (Satureja hortensis L.) during the flowering stage cultivated under the ecological conditions of Serbia. The summer savory essential oil (SSEO) was extracted by Clevenger hydrodistillation. According to the GC/MS analysis of the SSEO, twenty-five and twenty-six components were detected in the non-shaded and shaded plants, respectively. The yield of SSEO from non-shaded plants was 1.64%, while SSEO from plants covered by shade nets was 1.76%. Carvracol (48.7–53.25%) and γ-terpinene (32.7%–36.8%) were found to be the main components in SSEO, followed by p-cymene (3.4%-3.2%), α-terpinene (2.9%-3.5%) and limonene (1.9-1.3%). In the DPPH assay, SSEO showed an IC50 of 0.99 μg mL−1 in shaded and an IC50 of 1.01 μg mL−1 in non-shaded plants. Additionally, SSEO exhibited strong antibacterial activity against Escherichia coli (44.3–48 mm inhibition zone), Bacillus subtilis (34.7–41.0 mm), Klebsiella pneumoniae (28.3–29.0 mm) and Proteus vulgaris (21.0–24.3 mm). A possible practical application of this study would be to grow summer savory at higher plant densities, or as an intercrop, because it does not require too much light for production.

Shade Nets Reduced Growth, Nutrition, and Sugars of Hydroponic Lettuce and Basil

Colored shade nets are known to alter the light quality and quantity and thus can influence plant growth and nutritional quality of crops. Lettuce (‘Lollo Antonet’ and ‘Green Forest’) and basil (‘Aroma-2’ and ‘Genovese’) were grown in ebb-and-flow hydroponic tables for 4 weeks. Colored shade nets of aluminet, black, pearl, and red with 50% shading intensity along with a control (no-shade) were used in this experiment. Data for plant growth and leaf quality attributes were collected at harvest time. The no-shade treatment showed increased shoot fresh and dry weight, sugar, and relative chlorophyll content in both lettuce and basil cultivars, whereas plant height and net photosynthesis rates were increased under aluminet, pearl, and red nets. In basil, calcium and sulfur were greatest under no-shade, whereas zinc and copper were greatest under aluminet. Zinc, iron, calcium, magnesium, and manganese concentrations were greatest under no-shade in lettuce. The pearl-colored net increased leaf soluble solids content. No-shade produced the greatest starch values in basil, whereas pearl shade net produced the greatest starch in ‘Lollo Antonet’ in the fall. Light spectra varied with shade net resulting in 90%, 65%, 50%, 30%, and 70% of incident light occurring between 400 and 700 nm for no-shade, pearl, aluminet, black, and red shade nets, respectively. Overall, lettuce and basil plants under no-shade (daily light integral of 20 to 24 mol·m−2·d−1 and temperature of 26 to 30 °C) had increased plant growth and leaf quality in late spring and fall, compared with colored shade nets.