• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.150-156
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• 2008

The influences of night break by costly artificial light sources were investigated on the photo-morphogenesis and growth of leafy perilla (Perilla ocymoides L.). The irradiation of red, blue, and three-colored light for night break significantly increased the stem length and stem diameter compared to dark. Three-colored light gave the highest fresh and dry weight of stem, followed by red and blue light. Floral induction was suppressed up to 100 days after the night break, by red and three-colored light, but the plants grown under the dark or treated with blue light showed 85% and 31% flowering rate, respectively. The time needed for floral induction after night break was 60 days in dark and 80 days in blue light. The number of leaf, leaf area, and fresh weight per plant were the highest in red and three-colored light night break, followed by blue light and dark. The photosynthetic rate observed 80 days after night break was the highest in red light, followed by blue and three-colored light. A low light compensation point of $20\;{\mu}mol\;m^{-2}{\cdot}s^{-1}$ was observed in three-colored light, while red and blue light tended to show higher measurements.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.429-437
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• 2019

This study was conducted to examine the effect of humidification and shading during cutting propagation on growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' plants at a propagation stage. The runner cuttings were stuck on Nov. 23, 2017 in propagation benches set in a Venlo-type glasshouse. Four shading treatments, no shading (control, C), 55% shading with white lawn (W55), 55% black shading net (B55), or 100% black plastic film (B100) with either an intermittent fog system (H) or without fog system. The shading and fog systems were removed 2 weeks after sticking of strawberry cuttings. A nutrient solution for strawberry, which was developed by Yamazaki, was supplied once a day with electrical conductivity (EC) $1.6dS{\cdot}m^{-1}$ and pH 5.8. Growth parameters such as plant height, longest root, crown diameter, leaf chlorophyll, leaf area and fresh and dry weight were measured at 7 days and 26 days after sticking. There was no significant difference in growth of above-aerial part of strawberry. The overall growth of the strawberry roots was better grew by providing fog than that not provide fog. The root fresh weight and root dry weight after 26 days after sticking of strawberry cutting was the best in the treatment that provided fog system without shading (CH). The longest root after 26 days after sticking of strawberry cutting was the best in the treatments that provided fog system with either 55% white lawn (W55H) and 55% black shading net (B55H). These results suggest that morphogenesis of these plants were affected by humidification and shading types. In a broader perspective, these results can be used to optimize studies of other crops grown from cuttings.