• Proceedings of the Ginseng society Conference
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• 1980.09a
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• pp.39-47
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• 1980

The harvesting and export of Canadian ginseng from the cool, shady hardwood forests of southern Canada can be traced to 1796. Because of its high dollar value and diminishing woodland supplies it was decided in 1896 that it should be cultivated under wood lath screens. Present day economics dictate changes in production techniques to allow for a decreasing supply of expensive labour. Traditional wooden lath screens have a surface area of wood of 70 per cent and permit light penetration of only about 18 per cent. Experimental woven black polypropylene shade has an estimated surface area of 72 per cent and permits light pentration of about 28 per cent. While differences in air and leaf temperatures under the two shade structures can be measured it is doubtful if these are great enough to cause differences in plant growth under the two structures. Shade grown ginseng had a low fresh and dry weight and total chlorophyll content (ratio of a to b was 3 to 1) comparable to other shade species. There was no differences in fresh and dry weight and chlorophyll content of leaves from plants grown under the two shade structures. Maximum net photosynthesis of leaves was 0.175 g $CO_2\;m^{-2}\;hr^{-1}$ and light saturation level was about $200{\mu}E\;m^{-2}\;s^{-1},$ or about 10 per cent of full sunlight.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.680-689
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• 2008

This present study was conducted to investigate photosynthetic responses and chlorophyll fluorescence performances of Cornus controversa, Fraxinus rhynchophylla, Betula schmidtii, Prunus leveilleana, and Acer mono seedlings growing under four different light intensity regimes (full sun, and 65~72%, 29~40%, 7~12% of full sun). As result, Cornus controversa, Fraxinus rhynchophylla, and Betula schmidtii showed outstanding photosynthetic capacities in full sun and showed low shade tolerance. Prunus leveilleana showed good photosynthetic capacity in three treatment levels except for 7~12% of full sun and showed common shade tolerance. While, Acer mono showed good photosynthetic capacity and chlorophyll fluorescence in 29~40% of full sun. Acer mono showed the highest shade tolerance compared to the other four species.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.188-192
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• 2005

To seek for proper regeneration methods with under-planting, Photosynthetic rate and chlorophyll contents of three broad-leaved species seedlings, Kalopanax pictum, Fraxinus rhynchophylla and Cornus controversa, were measured and compared between growing sites, below the canopy of Larix kaemferi and open land in the forest. Nursery stocks was planted in open nurs- ery in the forest in late April, 1997, and under-planting below the canopy of Larix kaemferi was conducted in late April, 1998. This experiment examined the relationships between shade-tolerance and physiological response to different light environment by tree species. To adapt the shade environment, leaves of Kalopanax pictum might be increased the more chlorophyll con- tents and photosynthetic ability than other species. From these results, shade-tolerance of the tree might be ordered Kalopanax pictum, Fraxinus rhynchophylla, and Cornus controversa.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.68-75
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• 2017

Demand for dwarf mondo grass (DMG; Ophiopogon japonicus 'Nanus') as an ornamental garden plant is expected to grow in the future. The purpose of this study was to investigate the levels of shade tolerance and ground cover by growing DMG under a variety of shade conditions for 18 months (May 2015~October 2016). DMG plants grown in bare ground for 3 years in Jangheung-gun, Jeonnam were used for testing. In an experimental site created in Naju city in Jeonnam, the DMG was planted in planters ($70cm{\times}70cm{\times}24cm$) and covered with a shading curtain to block natural light. Shaded conditions were then arranged under different levels of shade (0%, 55% and 75%). When the plants were grown, growth (leaf size, the number of leaves, fresh weight and dry weight) and ground coverage of DMG were analyzed. According to the results, DMG growth in terms of leaf size and the number of leaves was statistically higher under zero shade (full sunlight), when compared to other shaded conditions. DMG's fresh and dry weights were significantly greater under 0% and 55% shade, compared to those under 75% shade. The degrees of shade tolerance required for normal growth of DMG were found in the range of 0~50%, meaning that more than 50% shade may decrease plant growth. There were no statistical differences in ground coverage rates of DMG under different levels of shade. When 220 tillers were planted per $1m^2$ of plot, up to 80% of the area was covered by DMG after 18 months. Since DMG requires nutrient-rich soil to grow, sufficient nitrogen fertilizers are proposed to accelerate the ground cover of DMG. As DMG remained alive over the winter in the experiments, this study also suggests that DMG can be planted in the southern temperate region.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.370-372
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• 2017

Three greenhouse experiments with American ginseng seedlings growing under light levels from 4.8% to 68% showed a quadratic response for root dry weight, giving an optimal root dry weight of 239 mg (range 160-415 mg) at an optimal light level of 35.6% (range 30.6-43.2%).

• Korean Journal of Medicinal Crop Science
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• v.22 no.3
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• pp.210-216
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• 2014

The average and maximum temperature were $29.5^{\circ}C$ and $33.2^{\circ}C$ at 2:00 p.m. respectively, in the plastic-film house covered with shade net, and both of temperature were lower $0.6^{\circ}C$ and $1.3^{\circ}C$ than those of conventional shade. Light transmittance was 14% in the plastic-film house, while 9.9% in conventional shade during growing season from May to October. Withering time of aboveground part was on October 3rd in conventional shade with 60% of withering leaf, while it was on November 10th with 3.7% of withering leaf in the plastic-film house, about 40 days longer survival. The main disease incidence were 15% of anthracnose, 17% of leaf spot, 5% of phytophthora blight and 3% of gray mold in the conventional shade, while 0 ~ 0.1% disease incidence and 95% of emergence rate in the plastic-film house. The growth in the aboveground and underground part of ginseng was totally better, particularly characteristics affecting yield such as root length, main root length and diameter in the plastic-film house. The fresh weight was increased by 128% compared to the conventional shade and harvested roots per $3.3m^2$ were 36 roots in the conventional shade and 58 roots in the plastic-film house and futhermore yield per $3.3m^2$ was increased by 216% compared to the conventional shade. As covering materials, the rice straw in the plastic-film house was excellent. The ginsenoside contents affecting the quality of ginseng were higher in the plastic-film house indicating 0.333% of Rg1, 0.672% of Rb1, 0.730% of Rc and rate of red rusty root was less than 4.0 ~ 6.1%. Above the results, the quality of ginseng grown in the plastic-film house covered with shade net was improved than that of the conventional shade.

• Journal of Ginseng Research
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• v.12 no.1
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• pp.53-62
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• 1988

A field experiment was conducted in the arid interior of British Columbia, Canada to assess the seasonal soil temperature and moisture regimes in an American ginseng garden. As a consequence of the man-modified microclimate (elevated shade canopy and surface covering of mulch), the growing environment of the crop was fundamentally altered when compared to adjacent agricultural growing environments. In the ginseng garden, soil temperatures were found to remain low throughout the growing season whereas soil moisture remained high when compared with the outside garden environment. These results indicate that even in the hot, arid environment of the interior of British Columbia, the growing of ginseng is undertaken in sub-optimal conditions for the major part of the growing season. This poses challenges for the producers of the crop to modify the architecture of the gardens to enhance the soil regime without creating a deleterious aerial environment.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.36-48
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• 2010

This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents of Betula platyphylla var. japonica, Prunus leveilleana, Magnolia sieboldii, growing under four different light intensity regimes (full sun, and 64~73%, 35~42%, 9~16% of full sun). As result, Betula platyphylla var. japonica showed outstanding photosynthetic capacity and apparent quantum yield in full sun and showed low shade tolerance. Prunus leveilleana showed good photosynthetic capacity and apparent quantum yield in 64~73% or 35~42% of full sun and showed common shade tolerance. However, Magnolia sieboldii showed good photosynthetic capacity and apparent quantum yield in 35~42% of full sun, while the lowest in full sun. Magnolia sieboldii showed the highest shade tolerance compared to the other species. As the shading level increased, the total chlorophyll contents of all species increased with significant difference.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.198-207
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• 2000

The diurnal and seasonal changes of water potential and stomatal diffusive resistance were investigated with the effects of shade treatment to elucidate the water relations of the one year old seedlings of Betula platyphylla var. japonica, Zelkova serrata, Acer mono, and Prunus sargentii subjected to five levels of artificial shade treatments from full sun to nearly full shading of 2-6% relative light transmittance. Stomatal diffusive resistance measured in the four deciduous hardwood species studied changed variously by growing season and by species with the five shade treatments in the ranges of 1.7~25.1s/cm in 9 a.m., 2.3~33.3s/cm in 1 p.m., and 1.1~36.8s/cm in 5 p.m.. The measurements of stomatal diffusive resistance increased with increasing the shading, and were higher in September than in June or July in most of the species studied. The stomatal diffusive resistance measured in Zelkova serrata, Acer mono, and Prunus sargentii seemed to be approximately 3~4 times higher in nearly full shading treatment than in full sun. Water potential also changed variously by growing season and by species with five different shade treatments in the ranges of -0.17~-1.20MPa in 9 a. m., -0.30~-2.03MPa in 1 p. m., and -0.18~-1.34MPa in 5 p.m., respectively. On the reverse of stomatal diffusive resistance, the measurements of water potential were lower in September than in June or July in most of the species studied, and the seasonal differences were especially greater in Zelkova serrata comparing with the other species. The water potential seemed to be higher of approximately 2~3 times in nearly full shading treatment than in full sun in all of the species studied, but the differences among the shading treatments were less in water potential than in stomatal diffusive resistance. The differences of water potential following the gradient of five shading treatment seemed to be less in Betula platyphylla var. japonica than in the other species. In Acer mono and Prunus sargentii being some shade tolerant species, the water potential increased rapidly through about noontime with raising the shading level from full sun to the intermediate shading level of 22-28% relative light transmittance, but slowly with closing to full shading. In Betula platyphylla var. japonica and Zelkova serrata being shade intolerant species, the water potential increased gradually throughout the shading levels and the increment ranges were greater in Zelkova serrata than in Betula platyphylla var. japonica.

• The Korean Journal of Ecology
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• v.15 no.4
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• pp.377-386
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• 1992

Seasonal changes of symbiotic nitrogen-fixation activity and growth characteristics of four different natural populations of kummerowia striata were quantitatively analyzed during the growing period. the nitrogen-fixation activity of root nodules attained the maximum rates of 148, 132, 102 and 100$\muM\;C_2H_4\;\cdot\;g\;fw\;nodule^{-1}\;\cdot\;hr^{-1}$, respectively for sunny, multibranched, shade and unibranched populations at the optimum growth conditions. and the seasonal changes showed fluctuations by environmental conditions such as light, temperature, nutrient contents, water stress and plant ages, etc. The multibranched plant showed the greater amount of leaf and root nodule biomass, and the higher nitrogenase activity than the unibranched plant. the optimum conditions of leaf chloropht11 and water content of each organ indicated the active growth and the maximum fresh biomass of 4 different populations were 1.92, 1.85, 0.97 and 0.56 g $fw\cdotplant^{-1}$ for shade multibranched, sunny and unibranched populations, respectively.