• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.279-285
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• 2023

The demand for the fresh leaf of hooker chive, which is mainly used as functional roots and contains dietary sulfur or saponin, is increasing, but the leaves are only harvested 3-4 times per year under conventional field conditions. A plant factory system with different light qualities or intensities was applied for year-round production of the fresh leaves. Hooker chive (Allium hookeri) roots were hydroponically cultured under the plant factory with a mixture of blue plus red LEDs (Light-Emitting Diodes) and fluorescent lights for 50 weeks. Maximum leaf growth was attained with the 1.5 dS/m EC in the culture medium under the plant factory. The average leaf and shoot numbers of hooker chive grown hydroponically under a mixture of 200 µmol/m²/s LEDs increased by 147% and 140%, respectively compared to those under 100 µmol/m²/s LEDs at the 10th harvest. The leaf length of hooker chive grown under the LEDs treatment with the lowest light intensity significantly increased by 27% compared with the natural light treatment at the 10th harvest. However, there was no significant difference in leaf pigmentation between natural and 200 µmol/m²/s LEDs treatments. Plant factory with the mixture LEDs of blue and red lights can be applied for year-round production of hooker chive fresh leaves to ensure a stable supply of leafy vegetable throughout the year.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.348-353
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• 2009

Organic materials reveal the remarkable absorption and high buffer capacity for nutrient. Hence, organic materials need some different nutrient management skill from inorganic one. The objective of this study was to evaluate the effect of EC level of nutrient solution on the yield and quality of cut rose grown in the mixed substrate of coir and perlite. 3 EC levels of nutrient solution was treated, which were 0.7, 1.0, 1.3 times of standard solution (Aichiken solution, Japan) for cut rose hydroponics. EC of the standard solution was changed by season following as 1.4 (Apr.~June), 1.0 (July~Aug.), 1.4 (Sep.~Oct.), and $1.6dS{\cdot}m^{-1}$ (Nov.~Mar.) subsequently. The supply of nutrient solution was controlled by the signal of water potential at -5kPa using frequency domain reflectometry (FDR) sensor. As the results, marketable yield was similar for all treatments until 3rd harvest, but was decreased in high EC level from 4th harvest to 7th harvest as final. 0.7 times of standard solution decreased the ratio of unmarketable rose having short stem below 70cm and increased the ratio of high quality rose having long stem above 91cm. The flower weight and stem diameter of cut rose was higher in the low EC treatment than the others.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.73-80
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• 2004

Two red pepper(Capsicum annuum L.) cultivars, 'Geumtap' and 'Bugang', were cultivated at main producing areas in Korea and harvested four times in 1998 and 1999. Length, weight, dry matter ratio and color of red peppers were measured at each harvest. The relations between external characteristics with regional climatic elements such as total accumulated air temperature, total amount of precipitation and duration of sunshine during the fruit growing periods were compared. Length and fruit weight decreased by delayed harvest. These characteristics were shown significant difference according to cultivars, but not to growing year. Dry matter ratio had a tendency to increase at the 3rd and 4th harvest. The red color as measured a${\times}$L values of pepper powder, increased with being later in harvesting, but the trend was uncertain. In fruit growth, fruit length showed a positive correlation with total accumulated air temperature in later growth period of fruits(from 1st to 20th day before harvesting), and fruit weight had relationships with accumulated air temperature and total amount of precipitation in later growth period of fruit. There was no relation between dry matter ratio and climate elements. The red color was shown high correlations with total amount of precipitation and duration of sunshine. There was highest coefficient of determination($r^2$) in all external characteristics.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.280-284
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• 2009

One of the big obstacles to cultivate asparagus was long days taking before first harvesting. This study was carried out to hasten the first harvesting of summer planted asparagus in Jeju. Seedlings were raised for three months and planted June 20th in green house. Harvesting of Spring were separated into non-harvested (control) and harvested (partly-harvesting, completely-harvesting). The first year we could harvest $399kg{\sim}400kg/10a$ in harvesting treatment. Second year's yield was 834kg/10a in partly-harvesting, 825kg/10a in completely-harvesting treatment and 908kg/10a in control. There is no significant difference in second years yield regardless of first year's harvesting methods. The accumulated total yield was increased by 35% (l,229kg/10a) in harvesting treatment from the first spring compared with the control. Marketable yield was increased by 33% (1,116kg/10a) compared with non harvesting in first year (839kg/10a). The result of this study shows that doing harvest of the first year's spring in summer planting asparagus would be desirable for yield and possible to harvest after 8 months planting.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.421-427
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• 2020

In this study, we investigated the effect of nutrient supply periods on the fruit growth and quality of 'Duke' blueberry. The nutrient solution was contained with NO₃-N 4.6, NH₄-N 3.4, PO₄-P 3.3, K 3.0, Ca 4.6, and Mg 2.2 mmol·L^-1, and EC in the nutrient solution was 1.5 ds.m^-1. In 2017 and 2018, an individual blueberry bush was supplied with 8 L of the nutrient solution per week. In 2018, the drainage water quality of growing medium and fruit quality was investigated. The nutrient supply was started from April 01, and stopped at 15 days intervals as follows, 15 days before final harvest, at the final harvest date (June 30), 15 days after final harvest (DAFH), 30 DAFH, 45 DAFH, and 60 DAFH. The content of inorganic components in the growing medium was not significantly different by the stop time of nutrient supply, but the content of phosphorus (P₂O₅) tended to increase with the delay of stop time of nutrient supply. There were no significant differences in the fruit quality characteristics in terms of size, sugar content, and acidity among the different stop time of nutrient supply. The blueberry yield was tended to decrease with the delay of periods of nutrient supply, while the lowest yield of 1.8 kg was recorded when nutrient supply stopped at 45 and 60 DAFH.

• Korean Journal of Plant Resources
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• v.31 no.2
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• pp.136-148
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• 2018

The study was performed to investigate basic tree growth and fruit characteristics of 'Nero' black chokeberry (Aronia melanocarpa) depending on the different cultivation regions and altitudes in 2014, 2015. Tree growth and change of developmental stages of 'Nero' were similar regardless of meteorological environment of the four cultivation regions (Danyang, Okcheon, Yeongdong, and Geumsan) in 2014. Fruit characteristics of 'Nero' were significant differences in berry weight and anthocyanin content among the four orchards due to difference in cultivation techniques and relatively wide daily temperature range just before harvest, respectively. Tree growth and change of developmental stages of 'Nero' grown at the two orchards with different altitudes appeared to be similar during the successive years 2014 and 2015. Soluble solids content of the berries cultivated at low altitude (117 m) was higher than at high altitude (342 m). Acidity showed an inverse pattern with soluble solids content. Anthocyanin content increased progressively until at the middle of August, 2014-15 and then it decreased. Our results showed that black chokeberry is a species adaptive to the domestic environment as there were no differences in tree growth and change of developmental stages of 'Nero'. Considering fruit quality of black chokeberry such as soluble solids content, acidity, and anthocyanin content, our results suggest that optimal harvest period of black chokeberry 'Nero' is August 8 to 19.

• 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.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.290-296
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• 2011

In our study, oriental melon (Cucumis melo L. var makuwa Makino) was harvested in Seongju at major harvest time from June to August with the intervals of one month in 2009. In order to elucidate the effect of meteorological condition of harvest time on fruit quality and water-soluble vitamin contents of oriental melon, quality attributes including weight, hardness, and sugar were examined and water-soluble vitamin contents such as folic acid and vitamin C were analyzed. Fruit quality factors and water-soluble vitamin contents were the highest in June when rainfall was low and solar radiation was high. Meanwhile, both of them were the lowest in July when it was the worst weather condition for cultivation of oriental melon. After then, the contents of folic acid and vitamin C increased when the rainfall had decreased in Aug. The contents of both vitamins were much high in placenta than peel and flesh. In conclusion, the meteorological condition of the summer season by torrential rains and lack of solar radiation influence water-soluble vitamin contents, especially folic acid contents of oriental melon as well as quality attributes such as hardness and sugar.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.620-628
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• 2012

This study addressed the influence of forest harvesting on seasonal water table dynamics in small headwater riparian areas. Four treatments including potential Best Management Practices(BMPs) for ephemeral and intermittent streams were implemented(BMP1, BMP2, clearcut and reference). Water table measurements were obtained at bi-monthly intervals for 3 years including one year of pre- and two years of post-harvest observations. Overall, water table responses affected largely by rainfall amount. In addition, significant increases in water table levels following harvesting occurred throughout the two post-harvest years. Water table levels increased up to 28.2cm in the clearcut treatment during 2008 and up to 54.2cm in BMP2 during 2009. However, increase in water table elevation was not directly related to basal area removal despite considerable differences in basal area removed between BMP2 and clearcut treatments. Water table rises were apparent in that water table were more elevated during dry season(June through November) than during wet season(December through May). These seasonal fluctuations were presumably driven by changes in evapotranspiration caused by differences in leaf area of overstory canopy and understory following harvest.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.1-9
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• 2017

Forest harvest as large scale artificial disturbance makes edge environment in both clear-cutted and forested habitat. To clarify the development and recovery process of forest edge after disturbances is essential to understand vegetation responses and landscape level consequences such as edge-distance. In Korea, after clear-cutting, edge-related changes of environment and vegetation was not clarified yet. In Korean red pine (Pinus densiflora) forest, by applying space-for-time approach (sites with undisturbed and 1, 3, 10, 16 yr after cutting), the edge-related change of plant abundance and abiotic factors were determined for 20 line-transect (60 m) and 340 ($1m{\times}5m$) quadrats, and clarified depth and duration of the disturbance. Immediately after edge formation, within 15m form the edge, biotic and abiotic factors such as cover, richness, canopy openness, temperature and moisture content exhibited larger changes compared to forest interior. Plant abundance and abiotic variables were stabilized at the level of forest inside within 16 yr and 10 yr after edge creation, respectively. Woody (tree and shrub) species generally was showed larger increment with proximity to edge than did herb or graminoid species. In addition, negative interactions between woody and herbaceous species were detected during the period of forest edge closure. Our results suggested that depth of forest edge formed by clear-cutting of Korean red pine forest was at least from 15 m to 20 m and edge effect were likely sustained more than 16 years. As the first empirical study on edge-distance between two contrast habitats of clear-cutted and adjacent forest in South Korea, the analytical reality on landscape structure and habitat patches can be improved.