• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.226-233
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• 2023

High solar radiation in summer season causes excessive respiration of crops and reduces photosynthesis. In addition, the rainy season, which mainly occurs in summer, causes a low light condition inside the greenhouse. A low light condition can reduce crop growth and yield. This study was conducted to evaluate the effect of shade and supplemental lighting on the growth and yield of cucumber during summer season. Cucumber grafted seedlings were transplanted in two plastic greenhouses on August 30, 2022. To reduce the light intensity inside the greenhouse, a 50% shading screen was installed in one greenhouse. Supplemental lighting was conducted from September 7, 2022 to October 20, 2022. HPS (high-pressure sodium lamp), W LED (white LED, red:green:blue = 5:3:2), and RB LED (combined red and blue LED, red:blue = 7:3) were used for supplemental lighting sources, and non-treated (nonsupplemental lighting) was as the control. The supplemental lighting was conducted before sunrise and after sunset for 2 hours with a photosynthetic photon flux density of 150 ± 20 µmol·m^-2·s^-1. The plant height, leaf length, leaf width, and SPAD value tended to increase in the shading group. RB LED increased stem diameter regardless of shading treatment. Fresh and dry weights of fruits were not significantly different in shading and supplemental lighting. Average fresh weight of fruits was not significantly different among supplemental lighting as the harvest date passed. In conclusion, in this study 50% shade treatment significantly improved the growth of cucumber during the summer season. In addition, the growth and fruit characteristics are better than the control without supplemental lighting. This study can be used as basic research data for applying supplemental lighting technology to cucumber cultivation.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.352-363
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• 2021

The purpose of this study was to evaluate the load of nutrients contained in the drainage discharged from the facility horticultural complex and to use them for re-use of fluids and design for introduction of water treatment plants. Representative hydroponic cultivation crops were selected as tomato, paprika, cucumber, and strawberry, and the total number of samples analyzed for water quality was 80. As a result of the analysis, since various fertilizer components such as N, P, K⁺, Na⁺, Mg²⁺, Ca²⁺, Si₄⁺, HCO₃^-, Cl^-, S^2-, Fe, Mn, Cu, Zn, Mo and B are contained at very high concentrations in the drainage, the need for water treatment was confirmed. Through statistical analysis, it was analyzed that the drainage concentration of strawberries was lower than that of tomatoes, paprika, and cucumbers. In the case of tomatoes, these essential ion concentrations are the highest, so it was confirmed that they are subject to valuable resources in terms of reuse of fertilizers. The load of N and P of the drainage discharged from the facility horticultural complex 1m² was analyzed. For N, the daily processing capacity of 4.0 kg of tomatoes, 3.3 kg of paprika, 3.0 kg of cucumbers, and 1.5 kg of strawberries was calculated based on 1 ha. It was suggested that the P concentration needs a scale and capacity that can handle 0.5 kg of tomatoes, 0.6 kg of paprika, 0.4 kg of cucumber, and 0.2 kg of strawberries per day. Through this study, the amount of nitrogen and phosphorus contained in the drainage discharged from the greenhouse of each crop was evaluated to analyze the economy. In addition, it was expected to be used as basic data that can be used to calculate the treatment capacity to be reflected when introducing water treatment facilities in facility horticultural complexes for sustainable agriculture.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.435-442
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• 2015

The main objective of this work was to identify and evaluate possible substrate alternatives or amendments to peat moss. This study involves the physical and chemical characterization and growth test of wood sawdust and wood fiber in order to evaluate their use as components of horticultural media. The carbohydrate content, C/N ratio, pH, phenolic compound, total porosity and water holding capacity were 58.9%, 425.1, 4.8, 181.8 ($mg{\cdot}g^{-1}$), 82.5% and 47.1% in wood sawdust and 41.1%, 240.8, 5.9, 29.8 ($mg{\cdot}g^{-1}$), 90.6% and 56.2% in wood fiber, respectively. Wood sawdust (K, $998.0mg{\cdot}100g^{-1}$ ; Ca, $1196.0mg{\cdot}100g^{-1}$; Mg, $105.6mg{\cdot}100g^{-1}$) and wood fiber (K, $1250.1mg{\cdot}100g^{-1}$; Ca, $1982.6mg{\cdot}100g^{-1}$; Mg, $173.1mg{\cdot}100g^{-1}$) showed adequate mineral elements properties compared to peat moss (K, $0.02mg{\cdot}100g^{-1}$; Ca, $0.57mg{\cdot}100g^{-1}$; Mg, $0.13mg{\cdot}100g^{-1}$) for their use as growing media. The mixtures of the horticultural media were prepared using different substrate as wood sawdust and wood fiber to grow Chinese cabbage (Brassica campestris L.) in a greenhouse. The seed germination, leaf area and stem height were 75%, $0.50cm^2$ and 2.8 cm in PS substrate (containing 30% peat moss, 10% perlite and 60% wood sawdust) and 95%, $0.65cm^2$ and 3.3 cm in PF substrate (containing 30% peat moss, 10% perlite and 60% wood fiber), respectively. The seed germination and stem height of the PF substrate (containing 30% peat moss, 10% perlite and 60% wood fiber) was higher than those in peat moss (control). Utilization of wood by-product can be considered as an alternative media component to substitute the widely using expensive peat moss.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.194-199
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• 2011

This study was conducted to evaluate fertigation effects of pig slurry (PS) and chemical fertilizer (CF) in cucumber by investigating the growth and yield, nutrient content and uptake, nutrient use efficiency, and soil characteristics in greenhouse cultivation. The cropping patterns of cucumber were semi-forcing culture and retarding culture, and the experiment involves four treatments: No fertilizer (NF), $26mg\;L^{-1}$ and $52mg\;L^{-1}$ of N application by slurry composting biofiltration liquefied fertilizer (SCBLF), and $52mg\;L^{-1}$ of N treatment by chemical fertilizer. The difference on the plant height of cucumber between SCBLF and CF treatments was no significant, but fresh weight and dry weight of stem and root were higher in $26mg\;L^{-1}$ SCBLF treatment. The Ca content of the leaf was lower in the treatments of SCBLF and the K content of the root was lower in the $52mg\;L^{-1}$ CF treatment. The Ca content of the stem was lowest in the $52mg\;L^{-1}$ CF treatment and the mineral content of the fruit showed no significant difference. In case of semi-forcing culture, the gross yield was lower in the $52mg\;L^{-1}$ CF treatment and the yield of unmarketable fruit was lower in the SCBLF treatments. The nutrient use efficiency of cucumber is as follows: K (8.3 ~ 30.9%), N (4.2 ~ 13.0%), P (1.9 ~ 2.0%). The SCBLF treatments showed higher figure in the soil pH than that of the CF treatment, while EC and the content of $NO_3$-N were higher in the CF treatment than the former. The content of exchangeable K was higher in the plot treated with $52mg\;L^{-1}$ SCBLF, and there were no significant differences in the content of Ca and Mg between the treatments. In conclusion, it is suggested that the application of liquefied manure made from pig slurry may be able to replace the use of chemical fertilizer in nitrogen and potassium.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1181-1186
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• 2013

Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, Chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This study examined the influence of air temperature during seedling growth on the time required to reach the first fruit maturity and yield of hot pepper. Seedling plants of 'Super Manita' hot pepper was grown in temperatures $2.5^{\circ}C$ and $5.0^{\circ}C$ lower than the optimum temperature (determined by the average of temperatures for the past 5 years). Seedlings were transplanted into round plastic containers (30-cm diam., 45-cm height) and were placed in growth chambers in which the ambient temperature was controlled under natural sunlight. The growth of seedlings under lowered temperatures was reduced compared to the control. The mineral (K, Mg, P, N) concentrations in the leaf tissues were higher when plants were grown with the ambient temperature $2.5^{\circ}C$ lower than the optimum, regardless of changes in other growth parameters. Tissue calcium (Ca) concentration was the highest in the plants grown with optimum temperature. The carbohydrate to nitrogen (C/N) ratio, which was the highest (18.3) in the plants grown with optimum temperature, decreased concomitantly as the ambient temperature was lowered $2.5^{\circ}C$ and $5.0^{\circ}C$. The yield of the early harvested fruits was also reduced as the ambient temperature became lower. The first fruit harvest date for the plants grown with optimum temperature (June 27) was 13 days and 40 days, respectively, earlier than that in plants grown with $2.5^{\circ}C$ (July 10) and $5.0^{\circ}C$ (Aug 6) lower ambient temperatures. The fruit yield per plant for the optimum temperature (724 g) was the greatest compared to those grown with $2.5^{\circ}C$ (446 g) and $5.0^{\circ}C$ (236 g) lower temperatures. The result of this study suggests that the growers should be cautioned not to transplant their hot pepper seedlings too early into the field, since it may delay the time of first harvest eventually reducing total fruit yield.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.87-94
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• 2011

This study was carried out to investigate the effects of hot solution soaking and chilling treatment on sprouting and enlargement of bulblets obtained through in vitro culture in Korean native lilies with ornamental values. In vitro bulblets of Lilium cernuum, L. hansonii, L. hansonii for. mutatum, L. leichtlinii, and L. tsingtauense were soaked in distilled water or 100 $mg{\cdot}L^{-1}$ $GA_3$ and $GA_{4+7}$ solution maintained at $35^{\circ}C$ for two hours (hot water treatment) and/or exposed at $4^{\circ}C$ for 0, 4, or 8 weeks (chilling treatment) and then planted in plastic trays filled with media and grown in a greenhouse at $20^{\circ}C$ and under 16 h photoperiod. In all species, no bulblet propagated by tissue culture sprouted without chilling or hot water treatment due to dormancy. For dormancy breaking, $GA_{4+7}$ hot solution treatment increasing sprouting by 55-96%, whereas distilled water or GA was not effective in sprouting. Chilling treatment for 4 weeks induced sprouting by 50-70% in L. cernuum and L. leichtlinii, whereas 8 weeks was needed for sprouting of L. hansonii and L. hansonii for. mutatum. Combined treatment of hot water and chilling treatments synergistically promoted sprouting. Especially, in L. cernuum and L. hansonii, $GA_{4+7}$ hot solution soaking prior to chilling for 4 weeks promoted sprouting by 35-45% compared with the reverse order. Enlargement of bulblets resulted from increase in fresh weight and diameter was promoted by the treatments that increased the sprouting percentage of bulblets. Only in L. cernuum, shoots emerged from bulblets soaked in hot $GA_{4+7}$ solution or chilled at $4^{\circ}C$ and shoot emergence rate was highest in bulblets soaked in hot $GA_{4+7}$ solution and then chilled for 8 weeks. From these results, the most effective method for bulblet sprouting and enlargement was to soak in hot $GA_{4+7}$ solution and then chill for 4 weeks in L. hansonii, hansonii for. mutatum, and leichtlinii, and to soak in hot $GA_{4+7}$ solution and then chill for 4 weeks in L. cernuum and tsingtauense.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.400-406
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• 2018

In this experiment the effect of supplemental lighting on the growth and yield of cucumber (Cucumis sativus L. 'Fresh') plants during low radiation period of winter season were investigated in glasshouses using common high-pressure sodium (HPS) lamps and newly developed plasma lighting system (PLS) lamps. Plants grown without supplemental lighting were considered as a control. Supplemental lighting was provided from November 20th, 2015 to March 15th, 2016 to ensure 14-hour photoperiod (natural+supplemental light), also lamps were operated automatically when the outside sun radiation levels were less than $100W{\cdot}m^{-2}$. Spectral analysis showed that HPS lamp had a discrete spectrum, lacked of the radiation in the 400-550 nm wave band (blue-green light), but had a high output in the orange-red region (550-650 nm). A higher red light output resulted in an increased red to far-red (R/FR) ratio in HPS lamp. PLS had a continuous spectrum and had a peak radiation in green region (490-550 nm). HPS has 12.6% lower output in photosynthetically active radiation (PAR) but 12.6% higher output in near infra-red (NIR) spectral regions compared to PLS. Both HPS and PLS lamps emitted very low levels of ultra-violet radiation (300-400 nm). Supplemental lighting both from HPS and PLS lamps increased plant height, leaf number, internode number and dry weight of cucumber plants compared to control. Photosynthetic activity of cucumber plants grown under two supplemental lighting systems was comparable. Number of fruits per cucumber plant (fruit weight per plant) in control, PLS, and HPS plots were 21.2 (2.9 kg), 38.7 (5.5 kg), and 40.4 (5.6 kg), respectively, thereby increasing yield by 1.8-1.9 times in comparison with control. An analysis of the economic feasibility of supplemental lighting in cucumber cultivation showed that considering lamp installation and electricity costs the income from supplemental lighting increased by 37% and 62% for PLS and HPS lamps, respectively.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.886-897
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• 2016

The physical properties of rooting media for the establishment of plugs in a greenhouse are modified according to variations in the greenhouse environment throughout the season. In this study, we established a standard for rooting media for the production of plug seedlings for each growing season (summer, winter and spring fall). Eight types of peatmoss (PM) and 4 types of perlite (PL) commonly used in Korea were collected and blended with the ratio of 7 parts PM to 3 parts PL (v/v) to make 32 different rooting media blends. We determined the total porosity (TP), container capacity (CC), air-filled porosity (AFP), pH, and electrical conductivity (EC) of the 32 media blends, and 6 media blends were selected for seasonal use. We also conducted additional analyses for plant easily available water (EAW), buffering water (BW), cation exchange capacity (CEC), and nutrient contents in the 6 media blends. The TP, CC, and AFP of the 32 media blends ranged from 64.7 to 96.0%, 42.9 to 90.1%, and 1.3 to 27.8%, respectively, indicating that the physical properties were strongly influenced by the type of PM and PL. The pH and EC of the PMs ranged from 2.96 to 3.81 and 0.08 to $0.47dS{\cdot}m^{-1}$, respectively. However, after blending the PM with the PL the pH was raised and the EC was lowered The media blends selected for the summer growing season were Blonde Golden peatmoss (BG) + No. 1 perlite size < 1 mm (PE1) and Latagro 0-10 mm (L1) + No. 2 perlite size 1-2 mm (PE2). These two media blends had 89.8-90.9% of TP, 80.8-81.3% of CC, and 9.0-9.7% of AFP. The media blends selected for the winter growing season were Sfagnumi Turvas (ST) + PE2 and Latagro 20-40 mm (L3) + PE2. These media blends had 79.9-86.7% of TP, 60.4-74.9% of CC, and 11.8-19.6% of AFP. The TP, CC, and AFP of two media blends, BG + No.3 perlite 2-5 mm (PE3) and Orange peatmoss (O) + PE3, selected for the spring and fall growing seasons, respectively, were 85.2-87.3%, 77.9%, and 7.4-9.4%, respectively. The percentage of EAW of the media blends selected for the spring, summer, and winter growing seasons ranged from 24.2-24.9%, 22.0-28.6%, and 18.0-21.8%, respectively, but the percentages of BW were not significantly different among the selected root media blends. The pH, EC, and CEC of the 6 selected media blends ranged from 3.11-3.97, $0.06-0.26dS{\cdot}m^{-1}$, and $97-119meq{\cdot}100g^{-1}$, respectively.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.209-213
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• 2013

This study was conducted to produce heads of artichoke in July in Korea. The artichoke was planted in the Autumn and it could be reaped heads of artichokes in late of May in Korea. It can inform us that the artichoke need under some low temperature during the Winter to open flowers. In order to harvest heads of artichoke in the Summer two kinds of cultivar 'Green Globe' and 'Imperial Star' those were grown for 4 weeks in green house of $17^{\circ}C$ which were treated at 3, 6, 9 and $12^{\circ}C$ chamber for 4 weeks and then planted the 8th April. Plant distance was $150{\times}50$ cm. After 3 months most of artichoke of 'Imperial Star (IS)' made heads. Especially, the artichokes 'IS' were treated at $6^{\circ}C$ made heads 63% of plants but those at $12^{\circ}C$ made heads 33% and the artichokes (no treatment at low temperature) grown in greenhouse at $17^{\circ}C$ for 8 weeks made heads 5% of plants. 'Green Globe (GG)' made heads 28% of plants at $9^{\circ}C$ and 10% at $12^{\circ}C$, and 'GG' grown in greenhouse at $17^{\circ}C$ for 8 weeks never had made any head. The weights of head were 97 g and 86 g in 'IS' and 'GG' respectively. The yield of heads were 215 and 108 kg/10a in 'IS' and 'GG' respectively.