scholarly journals Intensity of Sole-source Light-emitting Diodes Affects Growth, Yield, and Quality of Brassicaceae Microgreens

HortScience ◽  
2019 ◽  
Vol 54 (7) ◽  
pp. 1168-1174 ◽  
Author(s):  
Chase Jones-Baumgardt ◽  
David Llewellyn ◽  
Qinglu Ying ◽  
Youbin Zheng
Keyword(s):  
Light Emitting Diodes ◽  
Flux Ratio ◽  
Growth Yield ◽  
Sole Source ◽  
Leafy Vegetables ◽  
Photon Flux ◽  
Light Emitting ◽  
Yield And Quality ◽  
Lighting Environment

Indoor farming is an increasingly popular approach for growing leafy vegetables, and under this production system, artificial light provides the sole source (SS) of radiation for photosynthesis and light signaling. With newer horticultural light-emitting diodes (LEDs), growers have the ability to manipulate the lighting environment to achieve specific production goals. However, there is limited research on LED lighting specific to microgreen production, and available research shows that there is variability in how microgreens respond to their lighting environment. The present study examined the effects of SS light intensity (LI) on growth, yield, and quality of kale (Brassica napus L. ‘Red Russian’), cabbage (Brassica oleracea L.), arugula (Eruca sativa L.), and mustard (Brassica juncea L. ‘Ruby Streaks’) microgreens grown in a walk-in growth chamber. SS LEDs were used to provide six target photosynthetic photon flux density density (PPFD) treatments: 100, 200, 300, 400, 500, and 600 μmol·m−2·s−1 with a photon flux ratio of 15 blue: 85 red and a 16-hour photoperiod. As LI increased from 100 to 600 μmol·m−2· s−1, fresh weight (FW) increased by 0.59 kg·m−2 (36%), 0.70 kg·m−2 (56%), 0.71 kg·m−2 (76%), and 0.67 kg·m−2 (82%) for kale, cabbage, arugula, and mustard, respectively. Similarly, dry weight (DW) increased by 47 g·m−2 (65%), 45 g·m−2 (69%), 64 g·m−2 (122%), and 65 g·m−2 (145%) for kale, cabbage, arugula, and mustard, respectively, as LI increased from 100 to 600 μmol·m−2· s−1. Increasing LI decreased hypocotyl length and hue angle linearly in all genotypes. Saturation of cabbage and mustard decreased linearly by 18% and 36%, respectively, as LI increased from 100 to 600 μmol·m−2·s−1. Growers can use the results of this study to optimize SS LI for their production systems, genotypes, and production goals.

scholarly journals Light Intensity and Quality from Sole-source Light-emitting Diodes Impact Growth, Morphology, and Nutrient Content of Brassica Microgreens

HortScience ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 497-503 ◽  
Author(s):  
Joshua R. Gerovac ◽  
Joshua K. Craver ◽  
Jennifer K. Boldt ◽  
Roberto G. Lopez
Keyword(s):  
Light Emitting Diodes ◽  
Dry Weight ◽  
Nutrient Content ◽  
Sole Source ◽  
Photon Flux ◽  
Light Sources ◽  
Growth Morphology ◽  
Hypocotyl Length ◽  
Photoelectric Conversion ◽  
Light Emitting

Multilayer vertical production systems using sole-source (SS) lighting can be used for the production of microgreens; however, traditional SS lighting methods can consume large amounts of electrical energy. Light-emitting diodes (LEDs) offer many advantages over conventional light sources, including high photoelectric conversion efficiencies, narrowband spectral light quality (LQ), low thermal output, and adjustable light intensities (LIs). The objective of this study was to quantify the effects of SS LEDs of different light qualities and intensities on growth, morphology, and nutrient content of Brassica microgreens. Purple kohlrabi (Brassica oleracea L. var. gongylodes L.), mizuna (Brassica rapa L. var. japonica), and mustard [Brassica juncea (L.) Czern. ‘Garnet Giant’] were grown in hydroponic tray systems placed on multilayer shelves in a walk-in growth chamber. A daily light integral (DLI) of 6, 12, or 18 mol·m−2·d−1 was achieved from commercially available SS LED arrays with light ratios (%) of red:green:blue 74:18:8 (R74:G18:B8), red:blue 87:13 (R87:B13), or red:far-red:blue 84:7:9 (R84:FR7:B9) with a total photon flux (TPF) from 400 to 800 nm of 105, 210, or 315 µmol·m−2·s−1 for 16 hours. Regardless of LQ, as the LI increased from 105 to 315 µmol·m−2·s−1, hypocotyl length (HL) decreased and percent dry weight (DW) increased for kohlrabi, mizuna, and mustard microgreens. With increasing LI, leaf area (LA) of kohlrabi generally decreased and relative chlorophyll content (RCC) increased. In addition, nutrient content increased under low LIs regardless of LQ. The results from this study can help growers to select LIs and LQs from commercially available SS LEDs to achieve preferred growth characteristics of Brassica microgreens.

The growth and morphology of microgreens is associated with modified ascorbate and anthocyanin profiles in response to the intensity of sole-source light-emitting diodes

2020 ◽  
Author(s):  
Chase Jones-Baumgardt ◽  
Qinglu Ying ◽  
Youbin Zheng ◽  
Gale G. Bozzo
Keyword(s):  
Light Emitting Diodes ◽  
Photosynthetic Pigment ◽  
Sole Source ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Total Phenolic ◽  
Hypocotyl Length ◽  
Total Anthocyanin ◽  
Light Emitting ◽  
Phytochemical Profiles

Sole-source light-emitting diodes (LEDs) are alternatives to fluorescent tubes and high intensity discharge lamps that are routinely used for indoor cultivation of horticultural commodities, including microgreens. This study examined the effect of photosynthetic photon flux density (PPFD) from LEDs on phytochemical profiles in organically grown kale, cabbage, arugula, and mustard microgreens, and their association with growth and morphological attributes. LEDs were used to deliver a 15% blue light and 85% red light mixture to microgreens at varying PPFDs between 100 and 600 μmol m-2 s-1. For all microgreens, increased concentrations of ascorbate (total and reduced) and total anthocyanin were proportional to PPFD. Total phenolic concentrations were elevated in all four microgreens at high PPFDs, whereas chlorophyll concentrations declined in arugula cabbage and mustard. A principal component analysis revealed anthocyanins and phenolics were associated with ascorbate levels in all microgreens, but not with chlorophylls or carotenoids. At high PPFDs photosynthetic pigment levels were negatively associated with fresh and dry weight to varying degrees. Anthocyanins, phenolics and ascorbate were negatively correlated with hypocotyl length and the colour attribute hue angle in all microgreens. These results indicate that microgreen growth and morphology are associated with altered phytochemical profiles during cultivation under sole source LEDs.

scholarly journals Effect of Molybdenum Rate on Yield and Quality of Lettuce, Escarole, and Curly Endive Grown in a Floating System

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 171 ◽  
Author(s):  
Alessandra Moncada ◽  
Alessandro Miceli ◽  
Leo Sabatino ◽  
Giovanni Iapichino ◽  
Fabio D’Anna ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Nutritional Quality ◽  
Growth Yield ◽  
Leafy Vegetables ◽  
Morphological Alteration ◽  
Nitrate Content ◽  
Yield And Quality ◽  
Floating System ◽  
Four Levels

Molybdenum (Mo) is required in enzymes involved in a number of different metabolic processes, and is crucial for the survival of plants and animals. The influence of nutrient solutions containing four levels of molybdenum (0, 0.5, 1.5, and 3.0 µmol/L) on growth, yield, and quality of lettuce, escarole, and curly endive grown in a hydroponic floating system was evaluated. Biometric, nutrient, and quality analyses were conducted to assess the response of each species to Mo. The results demonstrated that molybdenum is essential for harvesting marketable plants. Lettuce, escarole, and curly endive plants differed significantly in their response to molybdenum fertilization. The increase of Mo concentration in the nutrient solution was not harmful for plants and had no influence on yield and morphological traits of the leafy vegetables; however, it significantly affected some quality characteristics. Mo fertilization raised the nutritional quality by increasing ascorbic acid content up to 320.2, 139.0, and 102.1 mg kg−1 FW (fresh weight), and reducing nitrate content down to 1039.2, 1047.3, and 1181.2 mg kg−1 FW for lettuce, escarole, and curly endive, respectively. The addition of Mo in the nutrient solution increased the Mo content of plants up to 0.50, 4.02, and 2.68 μg g−1 FW for lettuce, escarole, and curly endive, respectively. Increasing Mo supply to lettuce, escarole, and curly endive up to 3.0 µmol L−1 could lead to a higher nutritional quality with no significant morphological alteration or yield loss.

scholarly journals Light Intensity and Light Quality from Sole-source Light-emitting Diodes Impact Phytochemical Concentrations within Brassica Microgreens

2017 ◽  
Vol 142 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Joshua K. Craver ◽  
Joshua R. Gerovac ◽  
Roberto G. Lopez ◽  
Dean A. Kopsell
Keyword(s):  
Light Intensity ◽  
Light Quality ◽  
Light Emitting Diodes ◽  
Sole Source ◽  
Photon Flux ◽  
Total Phenolic ◽  
Light Emitting ◽  
Phytochemical Content ◽  
Light Intensities ◽  
Phenolic Concentration

Multilayer vertical production systems using sole-source (SS) light-emitting diodes (LEDs) can be an alternative to more traditional methods of microgreens production. One significant benefit of using LEDs is the ability to select light qualities that have beneficial impacts on plant morphology and the synthesis of health-promoting phytochemicals. Therefore, the objective of this study was to quantify the impacts of SS LEDs of different light qualities and intensities on the phytochemical content of brassica (Brassica sp.) microgreens. Specifically, phytochemical measurements included 1) total anthocyanins, 2) total and individual carotenoids, 3) total and individual chlorophylls, and 4) total phenolics. Kohlrabi (Brassica oleracea var. gongylodes), mustard (Brassica juncea ‘Garnet Giant’), and mizuna (Brassica rapa var. japonica) were grown in hydroponic tray systems placed on multilayer shelves in a walk-in growth chamber. A daily light integral (DLI) of 6, 12, or 18 mol·m−2·d−1 was achieved from SS LED arrays with light ratios (percent) of red:blue 87:13 (R87:B13), red:far-red:blue 84:7:9 (R84:FR7:B9), or red:green:blue 74:18:8 (R74:G18:B8) with a total photon flux from 400 to 800 nm of 105, 210, or 315 µmol·m−2·s–1 for 16 hours, respectively. Phytochemical measurements were collected using spectrophotometry and high-performance liquid chromatography (HPLC). Regardless of light quality, total carotenoids were significantly lower under increasing light intensities for mizuna and mustard microgreens. In addition, light quality affected total integrated chlorophyll with higher values observed under the light ratio of R87:B13 compared with R84:FR7:B9 and R74:G18:B8 for kohlrabi and mustard microgreens, respectively. For kohlrabi, with increasing light intensities, the total concentration of anthocyanins was greater compared with those grown under lower light intensities. In addition, for kohlrabi, the light ratios of R87:B13 or R84:FR7:B9 produced significantly higher anthocyanin concentrations compared with the light ratio of R74:G18:B8 under a light intensity of 315 µmol·m−2·s−1. Light quality also influenced the total phenolic concentration of kohlrabi microgreens, with significantly greater levels for the light ratio of R84:FR7:B9 compared with R74:G18:B8 under a light intensity of 105 µmol·m−2·s−1. However, the impact of light intensity on total phenolic concentration of kohlrabi was not significant. The results from this study provide further insight into the selection of light qualities and intensities using SS LEDs to achieve preferred phytochemical content of brassica microgreens.

Response of growth, yield, and quality of pea shoots to supplemental light-emitting diode lighting during winter greenhouse production

2018 ◽  
Vol 98 (3) ◽  
pp. 732-740 ◽  
Author(s):  
Yun Kong ◽  
Dave Llewellyn ◽  
Youbin Zheng
Keyword(s):  
Total Yield ◽  
Growth Yield ◽  
Soluble Solids ◽  
Stem Length ◽  
Control Treatment ◽  
Photon Flux ◽  
Extension Rate ◽  
Greenhouse Production ◽  
Light Emitting ◽  
Yield And Quality

Low natural light levels during the winter months are a major limiting factor for greenhouse production in northern regions. To determine the effects of supplemental lighting (SL) on winter greenhouse production of pea shoots, crop growth, yield, and quality were investigated under the treatments of supplemental photosynthetic photon flux density (PPFD) of 50, 80, 110, and 140 μmol m−2 s−1, all with a 16 h photoperiod, plus a no-SL control treatment, inside a Canadian greenhouse from December to March. Light-emitting diodes with a red to blue PPFD ratio of 4:1 and peak wavelengths at 665 and 440 nm were used for the lighting treatment. During the trial period, the average natural daily light integral (DLI) inside the greenhouse was 5.3 mol m−2 d−1 and the average daily temperature was around 13 °C. Compared with the no-SL control, SL of 50–140 μmol m−2 s−1 increased stem length and leaf number before the first harvest and promoted the cumulative yield (kg m−2) of pea shoots throughout the five harvest times. The total yield (kg m−2) of five harvests and weekly average stem extension rate were proportional to supplemental PPFD within the range of 0–140 μmol m−2 s−1; however, SL of 50–80 μmol m−2 s−1, corresponding to total (natural + supplemental) DLI of 8.1–9.8 mol m−2 d−1, resulted in the best integrated quality based on the evaluation of individual fresh mass, soluble solids content, succulence, and firmness. Therefore, a total DLI ranging between 8.1 and 9.8 mol m−2 d−1 can be suggested as a target for winter greenhouse production of pea shoots under conditions similar to this trial.

scholarly journals Optical Characteristics of Greenhouse Plastic Films Affect Yield and Some Quality Traits of Spinach (Spinacia oleracea L.) Subjected to Different Nitrogen Doses

Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 200
Author(s):  
Ida Di Mola ◽  
Lucia Ottaiano ◽  
Eugenio Cozzolino ◽  
Leo Sabatino ◽  
Maria Isabella Sifola ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Spinacia Oleracea ◽  
Growth Yield ◽  
Ascorbic Acid Content ◽  
Leafy Vegetables ◽  
Nitrate Content ◽  
Diffuse Light ◽  
Yield And Quality ◽  
N Dose

Light and nitrogen strongly affect the growth, yield, and quality of food crops, with greater importance in green leafy vegetables for their tendency to accumulate nitrate in leaves. The purpose of this research was to explore the effect of two greenhouse films (Film A and B) on yield, and quality of spinach grown under different nitrogen regimes (not fertilized—N0%; sub-optimal N dose—N50%; optimal N dose—N100%). Film A and Film B were used as clear and diffused light films, with 75% and 87% thermicity, and 85% and 90% total transmittivity, respectively, where only Film B had a UV-B window. Film B elicited an increase in yield (22%) and soil–plant analysis development (SPAD) index (4.6%) compared to the clear film, but did not affect chlorophyll a, b, and total chlorophyll content. In addition, the diffuse film significantly decreased ascorbic acid in the crop but had no effect on lipophilic antioxidant activity and phenols content, but decreased ascorbic acid content. Finally, nitrate content was strongly increased both by nitrogen dose (about 50-fold more than N0%) and greenhouse films (about six-fold higher under diffuse light film), but within the legal limit fixed by European Commission. Therefore, irrespective of N levels, the use of diffuse-light film in winter boosts spinach yield without depressing quality.

Агрономическая эффективность промышленной (голландской) технологии возделывания картофеля

2018 ◽  
Author(s):  
C. Coy ◽  
A.V. Shuravilin ◽  
O.A. Zakharova
Keyword(s):  
Heavy Metals ◽  
Regression Analysis ◽  
Positive Response ◽  
Growth Yield ◽  
Correlation And Regression Analysis ◽  
Yield And Quality ◽  
Quality Of Products ◽  
High Degree ◽  
The Impact

Приведены результаты исследований по изучению влияния промышленной технологии возделывания картофеля на развитие, урожайность и качество продукции. Выявлена положительная реакция растений на подкормку K2SO4 в период посадки. Корреляционно-регрессионный анализ урожайности и качества клубней выявил высокую степень достоверности результатов опыта. Содержание нитратов и тяжелых металлов в клубнях было ниже допустимых величин.The results of studies on the impact of industrial technology of potato cultivation on growth, yield and quality of products. There was a positive response of plants to fertilizer K2SO4 in the period of planting. Correlation and regression analysis of yield and quality of tubers revealed a high degree of reliability of the results of experience. The contents of nitrates and heavy metals in tubers was below the permissible values.

Drip Irrigation and Stand Establishment Affect Yield and Quality of Cantaloupe

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 545d-545
Author(s):  
D.I. Leskovar ◽  
J.C. Ward ◽  
R.W. Sprague ◽  
A. Meiri
Keyword(s):  
Field Experiments ◽  
Irrigation System ◽  
Fruit Size ◽  
Growth Yield ◽  
Vegetable Production ◽  
Silty Clay ◽  
Dry Land ◽  
Stand Establishment ◽  
Yield And Quality

Water pumping restrictions of high-quality irrigation water from underground aquifers is affecting vegetable production in Southwest Texas. There is a need to develop efficient deficit-irrigation strategies to minimize irrigation inputs and maintain crop profitability. Our objective was to determine how growth, yield, and quality of cantaloupe (Cucumis melo L. cv. `Caravelle') are affected by irrigation systems with varying input levels, including drip depth position and polyethylene mulch. Stand establishment systems used were containerized transplants and direct seeding. Field experiments were conducted on a Uvalde silty clay loam soil. Marketable yields increased in the order of pre-irrigation followed by: dry-land conditions, furrow/no-mulch, furrow/mulch, drip-surface (0 cm depth)/mulch, drip-subsurface (10-cm depth)/mulch, and drip-subsurface (30 cm depth)/mulch. Pooled across all drip depth treatments, plants on drip had higher water use efficiency than plants on furrow/no-mulch or furrow/mulch systems. Transplants with drip-surface produced 75% higher total and fruit size No. 9 yields than drip-subsurface (10- or 30-cm depth) during the first harvest, but total yields were unaffected by drip tape position. About similar trends were measured in a subsequent study except for a significant irrigation system (stand establishment interaction for yield. Total yields were highest for transplants on drip-subsurface (10-cm depth) and direct seeded plants on drip-subsurface (10 and 30 cm depth) with mulch.

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