scholarly journals Effect of Colored Shadecloth on the Quality and Yield of Lettuce and Snapdragon

2017 ◽  
Vol 27 (6) ◽  
pp. 860-867 ◽  
Author(s):  
Tongyin Li ◽  
Guihong Bi ◽  
Judson LeCompte ◽  
T. Casey Barickman ◽  
Bill B. Evans
Keyword(s):  
Phenolic Compounds ◽  
Transpiration Rate ◽  
Physiological Responses ◽  
Green Leaf ◽  
Light Spectrum ◽  
Growth Indices ◽  
Leaf Transpiration ◽  
Ornamental Crops ◽  
Delayed Flowering ◽  
Leaf Lettuce

Colored shadecloths are used in the production of vegetable, fruit, and ornamental crops to manipulate the light spectrum and to induce specific plant physiological responses. The influence of three colored shadecloths (red, blue, and black) with 50% shade and a no-shade control on the production of two lettuce (Lactuca sativa) cultivars [Two Star (green-leaf) and New Red Fire (red-leaf)] and snapdragon (Antirrhinum majus) was investigated. Use of shadecloth increased plant growth indices of lettuce and total length of snapdragon flower stems (at the first harvest) compared with no-shade control. Red shadecloth resulted in longer flower stems of snapdragon (at the second harvest) than black and blue shadecloths and no-shade control. However, shadecloth delayed blooming of snapdragon for 1 week compared with no-shade control. Stomatal conductance (gs) and leaf transpiration rate of both lettuce cultivars and photosynthetic rate and transpiration rate of snapdragon were decreased in response to shadecloth treatments. All shadecloths decreased health beneficial flavonoids (luteolin/quercetin glucuronide and quercetin malonyl concentrations for both lettuce cultivars and cyanidin glucoside in red-leaf lettuce). The two lettuce cultivars varied in their phenolic compounds, with the green-leaf ‘Two Star’ having higher quercetin glucoside and caftaric acid than red-leaf ‘New Red Fire’, whereas ‘New Red Fire’ had higher concentrations of chlorogenic acid, luteolin/quercetin glucuronide, and quercetin malonyl. Shadecloths reduced substrate temperature and photosynthetically active radiation (PAR) to about half of full sunlight compared with no-shade control, which may have contributed to reduced gs and leaf transpiration (for lettuce and snapdragon), decreased phenolic compounds in lettuce, and delayed flowering of snapdragon.

scholarly journals Spectral Blocking of Solar Radiation in High Tunnels by Poly Covers: Its Impact on Nutritional Quality Regarding Essential Nutrients and Health-Promoting Phytochemicals in Lettuce and Tomato

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 524
Author(s):  
Myungjin Lee ◽  
Cary Rivard ◽  
Weiqun Wang ◽  
Eleni Pliakoni ◽  
Kelly Gude ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Solar Radiation ◽  
Nutritional Quality ◽  
Spectral Characteristics ◽  
Green Leaf ◽  
Essential Nutrients ◽  
Shade Cloth ◽  
High Tunnels ◽  
Health Promoting ◽  
Leaf Lettuce

Spectral characteristics of solar radiation have a major role in plant growth and development and the overall metabolism, including secondary metabolism, which is important for the accumulation of health-promoting phytochemicals in plants. The primary focus of this study was to determine the effect of spectral characteristics of solar radiation on the nutritional quality of lettuce (Lactuca sativa L., cv. red leaf ‘New Red Fire’ and green leaf ‘Two Star’ and tomato (Solanum lycopersicum L., cv. BHN-589) grown in high tunnels in relation to the accumulation of essential nutrients and phytochemicals. Solar spectrum received by crops was modified using photo-selective poly covers. Treatments included commonly used standard poly, luminescence poly (diffuse poly), clear poly, UV blocking poly, exposure of crops grown under the standard poly to full sun 2 weeks prior to harvest (akin to movable tunnel), and 55% shade cloth on the standard poly. All the poly covers and shade cloth reduced the PAR levels in the high tunnels, and the largest reduction was by the shade cloth, which reduced the solar PAR by approximately 48%. Clear poly allowed the maximum UV-A and UV-B radiation, while standard poly allowed only a small fraction of the solar UV-A and UV-B (between 15.8% and 16.2%). Clear poly, which allowed a higher percentage of solar UV-A (60.5%) and UV-B (65%) than other poly covers, increased the total phenolic concentration and the antioxidant capacity in red leaf lettuce. It also increased the accumulation of flavonoids, including quercetin-3-glucoside, luteolin-7-glucoside, and apigenin-3-glucoside in red leaf lettuce, compared to the standard poly. Brief exposure of crops grown in high tunnels to full sun prior to harvest produced the largest increase in the accumulation of quercetin-3-glucoside, and it also resulted in an increase in luteolin-7-glucoside and apigenin-3-glucoside in red leaf lettuce. Thus, clear poly and brief exposure of red leaf lettuce to the full sun, which can increase UV exposure to the plants, produced a positive impact on its nutritional quality. In contrast, shade cloth which allowed the lowest levels of solar PAR, UV-A and UV-B relative to the other poly covers had a negative impact on the accumulation of the phenolic compounds in red leaf lettuce. However, in green leaf lettuce, luminesce poly, clear poly, UV-block poly, and shade treatments increased the accumulation of many essential nutrients, including protein, magnesium, and sulfur in green leaf lettuce compared to the standard poly. Poly cover treatments including shade treatment did not affect the accumulation of either carotenoids (lutein, β-carotene, and lycopene) or essential nutrients in mature tomato fruits. The results show that clear poly cover can enhance the accumulation of many phenolic compounds in red leaf lettuce, as does the brief exposure of the crop to the full sun prior to harvest. Thus, UV radiation plays an important role in the accumulation of phenolic compounds in red leaf lettuce while the overall spectral quality of solar radiation has a significant influence on the accumulation of essential nutrients in green leaf lettuce.

scholarly journals Leaf Shape, Growth, and Antioxidant Phenolic Compounds of Two Lettuce Cultivars Grown under Various Combinations of Blue and Red Light-emitting Diodes

HortScience ◽  
2013 ◽  
Vol 48 (8) ◽  
pp. 988-995 ◽  
Author(s):  
Ki-Ho Son ◽  
Myung-Min Oh
Keyword(s):  
Phenolic Compounds ◽  
Leaf Shape ◽  
Leaf Length ◽  
Green Leaf ◽  
Total Phenolic ◽  
Light Emitting ◽  
Spad Value ◽  
Red Led ◽  
Leaf Lettuce ◽  
Phenolic Concentration

Light-emitting diodes (LEDs) of short wavelength ranges are being developed as light sources in closed-type plant production systems. Among the various wavelengths, red and blue lights are known to be effective for enhancing plant photosynthesis. In this study, we determined the effects of blue and red LED ratios on leaf shape, plant growth, and the accumulation of antioxidant phenolic compounds of a red leaf lettuce (Lactuca sativa L. ‘Sunmang’) and a green leaf lettuce (Lactuca sativa L. ‘Grand Rapid TBR’). Lettuce seedlings grown under normal growth conditions (20 °C, fluorescent lamp + high-pressure sodium lamp 177 ± 5 μmol·m−2·s−1, 12-hour photoperiod) for 18 days were transferred into growth chambers that were set at 20 °C and equipped with various combinations of blue (456 nm) and red (655 nm) LEDs [blue:red = 0:100 (0 B), 13:87 (13 B), 26:74 (26 B), 35:65 (35 B), 47:53 (47 B) or 59:41 (59 B)] under the same light intensity and photoperiod (171 ± 7 μmol·m−2·s−1, 12-hour photoperiod). Leaf width, leaf length, leaf area, fresh and dry weights of shoots and roots, chlorophyll content (SPAD value), total phenolic concentration, total flavonoid concentration, and antioxidant capacity were measured at 2 and 4 weeks after the onset of LED treatment. The leaf shape indices (leaf length/leaf width) of the two lettuce cultivars subjected to blue LEDs treatment were similar to the control, regardless of the blue-to-red ratio during the entire growth stage. However, 0 B (100% red LED) induced a significantly higher leaf shape index, which represents elongated leaf shape, compared with the other treatments. Increasing blue LED levels negatively affected lettuce growth. Most growth characteristics (such as the fresh and dry weights of shoots and leaf area) were highest under 0 B for both cultivars compared with all other LED treatments. For red and green leaf lettuce cultivar plants, shoot fresh weight under 0 B was 4.3 and 4.1 times higher compared with that under 59 B after 4 weeks of LED treatment, respectively. In contrast, the accumulation of chlorophyll, phenolics (including flavonoids), and antioxidants in both red and green leaf lettuce showed an opposite trend compared with that observed for growth. The SPAD value (chlorophyll content), total phenolic concentration, total flavonoid concentration, and antioxidant capacity of lettuces grown under high ratios of blue LED (such as 59 B, 47 B, and 35 B) were significantly higher compared with 0 B or control conditions. Thus, this study indicates that the ratio of blue to red LEDs is important for the morphology, growth, and phenolic compounds with antioxidant properties in the two lettuce cultivars tested.

scholarly journals Growth analysis of green-leaf lettuce under different sources and doses of organic and mineral fertilization

2019 ◽  
Vol 13 (2) ◽  
pp. 237-247
Author(s):  
Rúbia Rejane Ribeiro ◽  
Jose Luiz Rodrigues Torres ◽  
Valdeci Orioli-Junior ◽  
Hamilton Cesar De Oliveira Charlo ◽  
Dinamar Márcia Da Silva Vieira
Keyword(s):  
Organic Matter ◽  
Growth Analysis ◽  
Chicken Manure ◽  
Residual Effects ◽  
Green Leaf ◽  
Organic Fertilization ◽  
Mineral Fertilization ◽  
Lettuce Yield ◽  
Leaf Lettuce ◽  
Different Sources

The objective of this study was to evaluate the influence of different sources and doses of organic and mineral fertilization on the production of green-leaf lettuce. The experiment design used randomized blocks in a factorial scheme (6×3), with six doses of fertilizers (1 = 0; 2 = 25; 3 = 50; 4 = 100; 5 = 150, and 6 = 200% of the recommended fertilization for green-leaf lettuce crop) and three sources of fertilizers [cattle manure (CaM) and chicken manure (ChM), decomposed, on a wet basis and applied 100% at planting at the doses: CaM – 0, 12.5, 25, 50, 75, 100 Mg ha-1; ChM – 0, 5, 10, 20, 30, 40 Mg ha-1; mineral fertilization (MF) varying the N levels: 0, 37.5, 75, 150, 225, 300 kg ha-1 plus 400 kg ha-1 of P2O5 and 60 kg ha-1 of K2O]. The fertilization with CaM and ChM was more efficient than the MF at increasing the production of green-leaf lettuce, mainly because of  the higher residual effects of P in the Oxisol. The ChM provided a higher soil pH, P and K, while the CaM provided a higher soil Mg, organic carbon and organic matter. The dose with 144% of organic fertilization exclusively on a wet basis corresponding to 72 Mg ha-1 of CaM and 29 Mg ha-1 of ChM resulted in the highest green-leaf lettuce yield.

scholarly journals Parasitological analysis of green leaf lettuce cultivated in different production systems

2017 ◽  
Vol 38 (2) ◽  
pp. 801
Author(s):  
Juliana Santiago Santos ◽  
Cristina Atsumi Kuba ◽  
Francislaine Anelize Garcia Santos ◽  
Aline Da Silveira Batista ◽  
Stênio Clemente Paião Sitolino ◽  
...  
Keyword(s):  
Production Systems ◽  
Vegetable Consumption ◽  
Intestinal Parasites ◽  
Leafy Vegetables ◽  
Green Leaf ◽  
Organic System ◽  
Cultivation System ◽  
Hydroponic System ◽  
Sanitary Conditions ◽  
Leaf Lettuce

This study analysed parasite contamination in green leaf lettuce (Lactuca sativa), grown in different cultivation systems (conventional, organic, and hydroponic), from a family farmer cooperative in the municipality of Presidente Prudente, São Paulo, Brazil. Samples were collected at weekly intervals during five months, totalling 180 vegetable samples (60 samples of leaf lettuce from each cultivation system). Lettuce leaves were washed with 0.5% Extran MA 02, and the resulting fluid subjected to sedimentation and centrifugal flotation for recovery of parasite structures. Overall, 71 samples (39.4%) were contaminated with at least one parasite structure, 34 (47.9%) from lettuce grown in the hydroponic system, 20 (28.2%) from the organic system, and 17 (23.9%) from the conventional system. Entamoeba spp. cysts were the most common parasite structures found in the leafy vegetables, with the highest cyst counts found in the hydroponic system (p = 0.003). It is concluded that, regardless of the cultivation system (conventional, organic, or hydroponic), there is a possibility of green leaf lettuce contamination by intestinal parasites. Measures that improve sanitary conditions during production, as well as proper hygiene during the preparation of raw leafy vegetables, may be important to reduce contamination and consequent transmission of parasite diseases from raw leafy vegetable consumption.

scholarly journals Stability and adaptability of curled green-leaf lettuce lines using the REML/Blup mixed model

2018 ◽  
Vol 53 (3) ◽  
pp. 298-306
Author(s):  
Willame dos Santos Candido ◽  
Renato Silva Soares ◽  
Carolina Andrade Franco ◽  
Guilherme Matos Martins Diniz ◽  
Edgard Henrique Costa Silva ◽  
...  
Keyword(s):  
Mixed Model ◽  
Harmonic Mean ◽  
Green Leaf ◽  
Yield Traits ◽  
Plant Yield ◽  
Breeding Lines ◽  
Growing Seasons ◽  
Commercial Cultivars ◽  
The Stability ◽  
Leaf Lettuce

Abstract: The objective of this work was to estimate the stability and genotypic adaptability of advanced lines and cultivars of curled green-leaf lettuce (Lactuca sativa), in different growing environments and seasons, using the REML/Blup mixed model. Ten genotypes, seven cropping environments, and two growing seasons were studied in 2015. Plant yield traits were evaluated, and data were subjected to the Selegen-REML/Blup software. Genotype stability and adaptability were analyzed using the harmonic mean of genotypic values (HMGV) and the relative performance of genotypic values (RPGV), respectively. The harmonic mean of RPGV (HMRPGV) was used to simultaneously estimate the stability, adaptability, and yield of breeding lines or cultivars. Considering the combined analysis of the two seasons for the set of traits, the lines L6, L7, and L8 were selected as promising ones and recommended for planting. The breeding lines selected for all season exhibit good yield and are considered superior to the commercial cultivars Vanda and Vera.

scholarly journals Nitrogen Limited Red and Green Leaf Lettuce Accumulate Flavonoid Glycosides, Caffeic Acid Derivatives, and Sucrose while Losing Chlorophylls, Β-Carotene and Xanthophylls

PLoS ONE ◽  
2015 ◽  
Vol 10 (11) ◽  
pp. e0142867 ◽  
Author(s):  
Christine Becker ◽  
Branimir Urlić ◽  
Maja Jukić Špika ◽  
Hans-Peter Kläring ◽  
Angelika Krumbein ◽  
...  
Keyword(s):  
Caffeic Acid ◽  
Green Leaf ◽  
Flavonoid Glycosides ◽  
Caffeic Acid Derivatives ◽  
Leaf Lettuce ◽  
Β Carotene

Utilization of kudzu as a lead phytoremediator and the impact of lead on selected physiological responses

2013 ◽  
Vol 93 (5) ◽  
pp. 951-959 ◽  
Author(s):  
Kristin Schwarzauer-Rockett ◽  
Safaa H. Al-Hamdani ◽  
James R. Rayburn ◽  
Nixon O. Mwebi
Keyword(s):  
Phenolic Compounds ◽  
Stomatal Conductance ◽  
Lead Concentration ◽  
Ethylenediaminetetraacetic Acid ◽  
Physiological Responses ◽  
Dry Weight ◽  
Control Treatment ◽  
Total Phenolic ◽  
Plant Responses ◽  
The Impact

Schwarzauer-Rockett, K., Al-Hamdani, S. H., Rayburn, J. R. and Mwebi, N. O. 2013. Utilization of kudzu as a lead phytoremediator and the impact of lead on selected physiological responses. Can. J. Plant Sci. 93: 951–959. This study was carried out to evaluate kudzu [Pueraria montana var. lobata (Willd.)] in lead phytoremediation. The impact of lead (PbNO3) concentrations of 100 and 200 mg L−1 on plant growth, photosynthetic pigments, photosynthesis, and stomatal conductance were evaluated. Additionally, concentrations of phenolic compounds and anthocyanin were determined. The lead was dissolved in 0.142 g L−1 ethylenediaminetetraacetic acid (EDTA) and an EDTA control treatment was added to evaluate the impact of EDTA on the above selected plant responses. Root accumulation of lead was significantly higher than in the shoot. Kudzu growth in response to the presence of lead and EDTA in the Hoagland's solution was similar to that of the EDTA control, except for plants growing at 200 mg L−1, which showed significantly lower root dry weight. Total phenolic compounds increased with the presence of EDTA and lead in the Hoagland's solution. Photosynthetic rate, stomatal conductance, chlorophyll a and chlorophyll b, carotenoids, and anthocyanin were not different (P≤0.05) among the treatments, with the exception that carotenoids were significantly higher in plants growing in the presence of EDTA without lead compared with 200 mg L−1 lead concentration. Kudzu accumulated most of the lead in the root and therefore can be considered as a rhizofiltrator. As kudzu was able to accumulate 1.02% (wt/wt) of lead it can be considered a hyper-accumulator.

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