• Journal of Ginseng Research
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• v.15 no.1
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• pp.21-30
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• 1991

This study was conducted to know the elects of light intensity of polyethylene net shading on the growth status, photosynthesis and root yield of ginseng plants. Polyethylene net shading of loft transmittance was the best one among light intensities of polyethylene net used in view of photosynthesis and decreasing of early leaf defoliation. According to increase of light intensity under the shading chlorophyll contents of ginseng leaves were decreased. As it was increased over 2 mg/g Photosynthesis and total saponin of leaves showed on the decrease remarkably. The rate of alternaria blight of ginseng plants showed the positive correlation between light intensity and leaking rate. The shading of 10% transmittance in root yield was increased by 40% in 6-year-old ginseng plant as compared with common straw shading, due to decreased missing plant and increased root weight.

• Journal of Ginseng Research
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• v.15 no.1
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• pp.31-35
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• 1991

In order to know the optimum planting density under shading structures at different light intensity, We investigated the growth status, distribution of ginseng leaf area, correlation between planting density and root weight per plant and yield, correlation between leaf area index and root weight per plant and yield. According to the increase of planting density the leaf area per plant was decreased, but leaf area index (L.A.I) was increased. Ginseng leaf population at different lines under common straw shading were distributed mainly in frost lines but polyethylene net shading at 10fo light intensity were distributed equally in all lines. Optimum planting density in common straw shading at 5% light intensity was 55 plant per tan (90 cmX180 cm) and polyethylene net shading 81 10% light intensity was 60 plant per tan, in consideration of root weight and yield. Optimum leaf area index was 2.4 under common straw shading at 5% light intensity but was 2.7 under polyethylene net shading at 10% light intensity.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.104-111
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• 2023

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14-16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of 3.2×1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old 'Fuji'/M.9 high-density apple orchards.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.177-182
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• 2023

Iron (Fe) is a vital element for plants and other organisms, involving in several physiological processes including respiration, chlorophyll biosynthesis, and photosynthesis. Unfortunately, how Fe accumulation regulates in response to light quality has not been well established in plants. Therefore, the aim of the study was to explore the mechanism of Fe homeostasis by light quality. In this study, we found morpho-physiological attributes were significantly improved in response to blue (λmax: 450) compared to white (λmax: 500) and red (λmax: 660) light. The root-shoot length, plant biomass, photosynthesis efficiency (Fv/Fm) and leafgreen (SPAD) significantly declined in response to white and red light. However, these parameters were improved and iron deficiency was substantially alleviated by blue light exposure in alfalfa seedlings. This study might be useful to the forage breeders and farmers for improving alfalfa yield and nutritional benefits.

• Journal of Mushroom
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• v.8 no.4
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• pp.137-141
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• 2010

This experiment was carried out to clarify the effect of light qualities on the growth characteristics and yield of fruiting body in the cultivation of Lyophyllum ulmarium. The intensity of illumination by light qualities was in the order of white light(2,270Lux), yellow light(1,750Lux), blue light(460Lux) and red light(400Lux). An investigation of fruiting body showed these results that the pileus size and stipe diameter of fruiting body on CBM(Chungbuk mushroom)-1757 were much larger than Hypsizigus marmoreus, and an effect of yellow light seemed to be better than those of another light. In comparison with Hypsizigus marmoreus, the growth duration of CBM-1757 was shortened by 8 days which included 2 days for mycelial culture, 1 day for first pinning requirement and 1 day for growth. The growth duration in yellow light illumination was about 70 days showing the tendency of 2~4 days reduction. There were no differences in results such as number of effective stem and fresh weight. The yield of fruiting body per bottle in CBM-1757(95.6g) was little higher than Hypsizigus marmoreus(94.8g). By a white light's standard, the yields of blue and red light illumination were decreased by 2~9%, but that of yellow light illumination was increased by 8%. The chromaticity results showed that brightness, red and yellow coloration of CBM-1757 were higher than those of Hypsizigus marmoreus, and yellow light treatment was more effective than another light.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.17-21
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• 2003

This experiment was conducted to find out the method of preventing decrease in the marketable yield of oriental melon (Cucumis melo L. var. makuwa MAKINO) under low light intensity. By maintaining low light of 400 $\mu$mol$.$m$^{[-10]}$ 2$.$S$^{-1}$ from 10 days after fruit set to fruit enlargement period, the photosynthetic rate and chlorophyll contents of leaf were reduced. Leaves which had no urea application showed largely decreased photosynthetic rate The content of soluble solids was lower$.$ in the low light than natural light treatment. Regardless of foliar application of urea, % fermentation fruits was under 4% in the natural light treatment and over 10% in the low light treatment. The less the fruit thinning, the greater was % fermentation fruits under low light condition. The % fermentation fruits were 39% and 40% in no fruit thinning treatment. The harvest was delayed under low light condition regardless of foliar fertilization. As the number of thinned fruits was decreased, the harvest time was delayed more. Marketable yield per plant sharply decreased under low light intensity. Compared with natural light, the yield under low light treatment was 16∼34%. The treatment fertilized with 0.5% urea on leaf had 34% greater harvest index of marketable yield than other treatments. In conclusion, when the long low light condition from 10th day after fruiting was forecasted, thinning two fruits out of six fruits and two times foliar fertilization with 0.5% urea should be applied.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.422-427
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• 2003

Rhodopseudomonas palustris P4 can produce $H_2$ either from CO by water-gas shift reaction or from various sugars by anaerobic fermentation. Fermentative $H_2$ production by P4 is fast, but its yield is relatively low due to the formation of various organic acids. In order to increase $H_2$ production yield from glucose, P4 was investigated for the photo-fermentation of acetate which is a major by-product of fermentative $H_2$ production. Experiments were performed in batch modes using both light-grown and dark-grown cells. When the dark-grown P4 was challenged with light and acetate, $H_2$ was produced with the consumption of acetate after a lag period of 25 h. $H_2$ production was inhibited when a nitrogen source, especially ammonium, is present. When the dark-fermentation broth containing acetate was adopted for photo-fermentation with light-grown cells, $H_2$ production and concomitant acetate consumption occurred without a lag period. The $H_2$ yield was estimated as 2.4 - 2.8 mol $H_2/mol$ acetate and the specific $H_2$ production rate was as 9.8 ml $H_2/g$ cell${\cdot}$h, The fact that a single strain can perform both dark- and light-fermentation gives a great advantage in process development Compared to a one-step dark-fermentation, the combined dark- and light-fermentation can increase the $H_2$ production yield on glucose by two-fold.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.219-224
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• 2009

In this study, the characteristics of pullout behavior of Pressurized light-weight steel Anchor was investigated through centrifuge model tests considering pull-out angle $0^{\circ}$ with changing undrained shearstrength(0~1, 2~4, 5~7kPa) of clay. According to the results of tests, the yield pullout load of clay ground was gradually increased up to 30% as undrained shear strength was increased. Therefore, it was known that the yield pullout load was affected by increasing the undrained shear strength, in addition, the pattern of behavior was not changed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.475-483
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• 2015

We examined the effects of light colors (wavelength) and light quantities on the yield ratio and quality of cultivated cowpea sprouts. All light colors resulted in a lower cowpea sprout yield ratio compared to the untreated condition (darkness), but were similar in hard seed ratio. All light colors promoted the growth of the epicotyl and root when compared to the untreated condition, but limited the growth of the hypocotyl. White light (458 nm) significantly improved grade by increasing the lightness of the cotyledon and the hypocotyl and the yellowness of the hypocotyl. The Fe content of cowpea sprouts was higher in those grown under red light (632 nm), and the total amino acid content was higher for those grown under yellow light (560 nm), white light (458 nm), and blue light (460 nm) compared to plants grown in the untreated condition (darkness). The yield ratio of cowpea sprouts was lower in the yellow light condition (560 nm) at lower light quantity, but no differences were observed at other light colors and quantities. The lightness and yellowness of cowpea sprouts was higher in the yellow light (560 nm) and red light (632 nm) at lower light quantity, redness was lower. No significant differences were observed in the content of normal and inorganic components according to the light quantities of each light color, except that Fe content was higher in sprouts grown under red light (632 nm) as light quantity increased. Total amino acid content was slightly higher in sprouts grown under white light (458 nm) and blue light (460 nm) as light quantity increased.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.253-257
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• 2009

To analysis effect of environment factors on productivity of sweet pepper according to greenhouse covering material (glass, plastic film), this was investigated. In glasshouse, outside light was positively correlated with yield as that $100MJ{\cdot}m^{-2}$ of outside light increased $300{\sim}500g{\cdot}m^{-2}$, also cumulative temperature was same tendency. On possibility of model development for yield estimate cumulative temperature was high than outside light. According to covering material, leaf photosynthesis, productivity per out-side light and term in glasshouse was more high 13%, 46%, and 47% compared with plastic film house, respectively. Result of analysis of effect of light, temperature, and $CO_2$ on yield, relative yield coefficient, yield increment coefficient, and yield reduction coefficient in glasshouse were more high 25%, 73%, and 34% compared with plastic film house, respectively. Hence, sweet pepper's growing in glasshouse compare with plastic film house had more productivity, but that had more sensitivity to charge of environment factors.