scholarly journals Improving Cannabis Bud Quality and Yield with Subcanopy Lighting

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1593-1599 ◽  
Author(s):  
Dave Hawley ◽  
Thomas Graham ◽  
Michael Stasiak ◽  
Mike Dixon
Keyword(s):  
Significant Variation ◽  
Light Quality ◽  
Cannabis Sativa ◽  
Control Treatment ◽  
Plant Canopy ◽  
Specific Production ◽  
Spectral Quality ◽  
Terpene Content ◽  
Light Spectral Quality ◽  
Lower Plant

The influence of light spectral quality on cannabis (Cannabis sativa L.) development is not well defined. It stands to reason that tailoring light quality to the specific needs of cannabis may increase bud quality, consistency, and yield. In this study, C. sativa L. ‘WP:Med (Wappa)’ plants were grown with either no supplemental subcanopy lighting (SCL) (control), or with red/blue (“Red-Blue”) or red-green-blue (“RGB”) supplemental SCL. Both Red-Blue and RGB SCL significantly increased yield and concentration of total Δ9-tetrahydrocannabinol (Δ9-THC) in bud tissue from the lower plant canopy. In the lower canopy, RGB SCL significantly increased concentrations of α-pinine and borneol, whereas both Red-Blue and RGB SCL increased concentrations of cis-nerolidol compared with the control treatment. In the upper canopy, concentrations of α-pinine, limonene, myrcene, and linalool were significantly greater with RGB SCL than the control, and cis-nerolidol concentration was significantly greater in both Red-Blue and RGB SCL treated plants relative to the control. Red-Blue SCL yielded a consistently more stable metabolome profile between the upper and lower canopy than RGB or control treated plants, which had significant variation in cannabigerolic acid (CBGA) concentrations between the upper and lower canopies. Overall, both Red-Blue and RGB SCL treatments significantly increased yield more than the control treatment, RGB SCL had the greatest impact on modifying terpene content, and Red-Blue produced a more homogenous bud cannabinoid and terpene profile throughout the canopy. These findings will help to inform growers in selecting a production light quality to best help them meet their specific production goals.

EFFECTS OF LIGHT SPECTRAL QUALITY ON NUTRIENT UPTAKE BY TOMATO

1988 ◽  
Vol 68 (1) ◽  
pp. 287-289 ◽  
Author(s):  
N. TREMBLAY ◽  
M.-C. GASIA ◽  
M.-Th. FERAUGE ◽  
A. GOSSELIN ◽  
M. J. TRUDEL
Keyword(s):  
High Pressure ◽  
Calcium Uptake ◽  
Light Quality ◽  
Controlled Environment ◽  
Light Sources ◽  
Spectral Quality ◽  
Mineral Uptake ◽  
Tomato Plants ◽  
Light Spectral Quality ◽  
Nutrient Solutions

Young tomato plants (Lycopersicon esculentum Mill. ’Duranto’) were grown in a controlled environment under three light sources. The plants were fertilized with nutrient solutions containing either 45Ca, 86Rb, 59Fe or 54Mn. Calcium uptake increased significantly under white deluxe and grow-lux lamps as compared to high-pressure sodium, while Rb uptake was higher under gro-lux lamps. No significant differences in uptake were obtained for Fe or Mn among light sources.Key words: Tomato, Isotope, Mineral uptake, Light quality

Development of Redroot Pigweed Is Influenced by Light Spectral Quality and Quantity

Crop Science ◽  
2002 ◽  
Vol 42 (6) ◽  
pp. 1930-1936 ◽  
Author(s):  
Irena Rajcan ◽  
Majid AghaAlikhani ◽  
Clarence J. Swanton ◽  
Matthijs Tollenaar
Keyword(s):  
Spectral Quality ◽  
Redroot Pigweed ◽  
Light Spectral Quality

scholarly journals An Investigation of a Root Zone Heating System and Its Effects on the Morphology of Winter-Grown Green Peppers

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 933
Author(s):  
Muhammad Ameen ◽  
Zhuo Zhang ◽  
Xiaochan Wang ◽  
Muhammad Yaseen ◽  
Muhammad Umair ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Root Zone ◽  
Dry Weight ◽  
Heating System ◽  
Sustainable Growth ◽  
Control Treatment ◽  
Plant Canopy ◽  
Root Zone Temperature ◽  
Zone Temperature

The winter season in Nanjing is from December to February, with extremely low temperature and high humidity due to seasonal snowfall. During these extreme cold climatic conditions, plants have to survive severe heat stress conditions, even if they are being kept in greenhouses. The objective of this study was to investigate a heating system that can provide heat directly to the root zone instead of heating the entire greenhouse, which is a viable option to reduce energy consumption. Root zone heating could be an effective alternative for the sustainable development of plants during the winter. A novel type of root zone heating system was applied to evaluate the energy consumption during different greenhouse ambient temperature conditions, the effects of root zone heating systems on pepper plant morphology, and heat transfer rates to plant canopy in the greenhouse. The temperature treatments in root zone heating system were T-15, T-20, T-25, T-30, and a control treatment (TC) at 15 °C, 20 °C, 25 °C, and 30 °C, respectively, while TC received no heat. A simulation study was carried out to validate the root zone temperature. The results of the current investigation revealed that energy consumption has an inverse relationship to the ambient temperature of the greenhouse, while temperature gradients to the plant canopy observed from the lower to the upper part of the plant and the upper canopy experienced less temperature fluctuation as compared to the lower part of the plant. The results also showed that treatment T-20 had the maximum in terms of the leaf dry weight, stem diameter, and the number of leaves, while T-25 showed the maximum root dry weight and stem dry weight; T-30 and T-15 had minimum dry weights of plant segments among all treatments. Control treatment (TC) showed a minimum dry mass of plant. The root zone heating with optimal root zone temperature was found to be a viable and adaptable option as this leads to improved energy consumption patterns for the sustainable growth and development of plants in greenhouses during extremely low temperatures.

scholarly journals Genetic diversity in developmental responses to light spectral quality in barley (Hordeum vulgare L.)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Arantxa Monteagudo ◽  
Tibor Kiss ◽  
Marianna Mayer ◽  
Ana M. Casas ◽  
Ernesto Igartua ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Hordeum Vulgare ◽  
Spectral Quality ◽  
Hordeum Vulgare L ◽  
Developmental Responses ◽  
Light Spectral Quality

Evolution of the Cannabinoid and Terpene Content during the Growth of Cannabis sativa Plants from Different Chemotypes

2016 ◽  
Vol 79 (2) ◽  
pp. 324-331 ◽  
Author(s):  
Oier Aizpurua-Olaizola ◽  
Umut Soydaner ◽  
Ekin Öztürk ◽  
Daniele Schibano ◽  
Yilmaz Simsir ◽  
...  
Keyword(s):  
Cannabis Sativa ◽  
Terpene Content

Effect of Light Quality on Cannabinoid Content of Cannabis sativa L. (Cannabaceae)

1983 ◽  
Vol 144 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Paul G. Mahlberg ◽  
John K. Hemphill
Keyword(s):  
Light Quality ◽  
Cannabis Sativa ◽  
Effect Of Light

Responses to shading in Chenopodium album: the effect of the maternal environment and the N source supplied

2004 ◽  
Vol 82 (9) ◽  
pp. 1371-1381 ◽  
Author(s):  
Humberto F Causin
Keyword(s):  
Stem Elongation ◽  
Chenopodium Album ◽  
Shade Avoidance ◽  
Ambient Light ◽  
Spectral Quality ◽  
Maternal Environment ◽  
Nutrient Treatment ◽  
N Source ◽  
Light Spectral Quality ◽  
N Acquisition

To study the effect of the maternal environment and N sources in responses to shading in Chenopodium album L., seeds from plants grown at an ambient red/far red (R/FR) ratio (1.07) or a low R/FR ratio (0.39) were germinated in a greenhouse at ambient light. At 34 d after sowing (d.a.s.), they were exposed to either ambient R/FR (0.98) or low R/FR (0.21) progeny light treatments and fertilized with 2.7 mmol/L nitrogen supplied at 1:3 or 3:1 NO3– : NH4+ ratios. Two harvests were performed at 67 and 113 d.a.s. At each harvest, stem elongation traits and biomass of plant organs were recorded. In the first harvest, tissue N% and free NO3–-N concentrations were analyzed. In the first harvest, plants from the low R/FR maternal treatment were heavier and taller than the maternal controls when grown at an ambient R/FR and with a high NO3– supply. At the second harvest this difference persisted in most of the conditions tested. Stem elongation and relative biomass allocation to the stem increased in the low R/FR treated plants, although the effect varied during ontogeny and with the maternal and nutrient treatment considered. The studied factors also affected N acquisition and metabolism. It is concluded that responses to the light spectral quality as well as plant N economy are influenced by the R/FR ratio of the maternal environment and that their expression may be altered by the relative availability of NO3–-N and NH4+-N.Key words: ammonium, Chenopodium album, light spectral quality, maternal effects, nitrate, shade-avoidance responses.

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