• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.183-189
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• 2018

This study was carried out to investigate the effect of plant growth and production of tomato (Lycopersicon Esculentum Mill cv. Tefunis) according to the water content of non-recycled rockwool culture in high-rise tomato greenhouse. Daily irrigation amount was 3.8 times higher in the irrigation control by Integrated Solar Radiation (ISR) than in the Frequency Domain Reflectometry (FDR) sensor. Water content of ISR and FDR was 90-95 and 60-65%, respectively. Plant height and weight of tomato fruit was 1.2-1.9 times longer and 1.2-2.0 times heavier in the ISR than in the FDR sensor, respectively. No significantly differed to sugar content of tomato by treatments. Marketable fruits were the higher 1.3 times in the ISR compared with the FDR sensor. Cracking percentage in the ISR was also the higher 2.0 times compared with FDR sensor. Therefore, Irrigation control by ISR was appropriate to improve of plant growth and production of tomato with non-recycled rockwool culture in greenhouse during long-term cultivation.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.283-289
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• 2011

This study was conducted to examine the effects of defoliation treatment on the growth and yield of strawberry ($Fragaria{\times}ananassa$ cv. Maehyang and Seolhyang) during nursery period. Leaves of strawberry plantlet had been removed except two, three and four fully expanded leaves until planting date. As the intensity of defoliation was strong, the petiole length was reduced and overgrowth of strawberry plantlet was suppressed. Outer diameter of crown in defoliation treatments significantly decreased but inner diameter of crown was not significant. Number of primary roots of the 3 leaves or 4 leaves defoliation treatment generally tended to increase, but there was not significantly different among treatments. Fresh weight and leaf area in the defoliation treatments significantly decreased and the root weight were higher in partial 3 leaves or 4 leaves defoliation treatment but was not significantly different among treatments. Because T/R ratio decreased significantly as growth inhibition of above-ground part compared to underground part, it is considered easy to take rooting after plantlet plating. As the intensity of defoliation was strong, chlorophyll contents tended to decrease significantly. Reduction of the endogenous nitrogen by defoliation effectively led to promote floral differentiation at low temperature and short day condition. This promoted timing of budding and flowering and also induced uniform flowering after plantlet planting. Marketable fruit yield of 3 leaves defoliation treatment tended to be higher than the control.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.385-391
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• 2012

This study was conducted to investigate the effects of the runner cutting time on the growth and yield of strawberry (Fragaria ${\times}$ ananassa cv. Maehyang and Seolhyang) during nursery period of two consecutive years (2009 and 2010). Strawberry runners which connected from mother plants to daughter plants were cut 30, 20, 10 and 5 days before transplanting day (11 Sep. 2009 and 10 Sep. 2010). When runner cutting time delayed, more nutrition was supplied to the daughter plant until late nursery period. It showed that there was a tendency to increase the fresh weight, crown diameter and leaf chlorophyll content. On the other hand, when the runner was cut earlier, the growth of underground part such as root weight was improved. Irrigation demand increased to 29.7% in case of runner cutting from mother plant compared with runner non-cutting treatment. In addition, infection ratio of anthracnose through runner part was 37.6% higher in case of runner cutting than that of runner non-cutting treatment. After transplanting, budding and flowering period were delayed up to 2 or 3 days because of late runner cutting. But there was no significant difference in marketable fruit yield among runner cutting times. It is recommended to conduct runner cutting 5 or 10 days before transplanting for reducing the occurrence of anthracnose.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.304-311
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• 2021

This Experiment was conducted to determine the effects of light shield materials when melon grown inside a plastic greenhouse in summer season. The average temperatures were 36.6℃, 34.5℃ and 34.0℃ respectively for the control(non-shield), coating agent, and the white net. The light transmittances were 69% and 75%, respectively inside the greenhouse treated with the coating agent and white net immediately after applicants, compared with that inside the control greenhouse. At the 40 and 80 days after treatment, the light transmittances for the coating agent were 92% and 98%, respectively, indicating it was slowly decomposed and removed, but there was no change in the transmittance for the white net. While the leaf number did not differ among the treatments, the plant height was higher in the white net and shading agent than in control. The weight of the leaves, fresh-weight and dry-weight were no different from that of shading, but it became heavier in the later stages. The marketable fruit yield was increased by 6% for white nets and 5% for the coating agent compared to control, there was no statistical significance. Therefore, coating agent is considered as an effective method to lower temperature during high temperature period, but it is preferable to use it in consideration of cultivation period, because the coating agent is gradually removed.

• Journal of Environmental Science International
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• v.30 no.8
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• pp.605-612
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• 2021

Supply electrical conductivity (EC) concentration of the nutrition solution is an important factor in the absorption of nutrients by plants and the management of the root zone, as it can control the vegetative/reproductive growth of a plant. Paprika usually undergoes its reproductive and vegetative growth simultaneously. Therefore, ensuring proper growth of the plant leads to increased yield of paprika. In this study, growth characteristics of paprika were examined according to the EC concentration of a coir and a rockwool substrate. The supply EC was 1.0, 2.0, and 4.0 mS·cm^-1 applied at the initial stages of the growth using the rockwool (commonly used by paprika farmers) and the coir substrate with a chip and dust ratio of 50:50 and 70:30. For up to 16 weeks of paprika growth, EC concentrations of 1.0 and 2.0 mS·cm^-1 were found to have a greater effect on the growth than EC at 4.0 mS·cm^-1. The normality (marketable) rate of fruit, the soluble solid content, and paprika growth showed that the coir was generally better than the rockwool regardless of the supply EC concentration. The values of the yield per plant at an EC concentration of 4.0 mS·cm^-1 was mostly similar at 1.6 kg (coir 50:50), 1.5 kg (coir 70:30) and 1.5 kg (rockwool), but the yield of the rockwool was 88%, which was lower than 98% and 94% yield of the coir substrate. Therefore, this concludes that coir substrate is more effective than rockwool at improving paprika productivity. The results also suggest that the use of coir substrate for paprika has many benefits in terms of reducing production costs and preventing environmental destruction during post-processing.

• Journal of the Korean Society of International Agriculture
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• v.31 no.2
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• pp.178-182
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• 2019

'Muha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2015. The 'Muha' cultivar originated from a cross between 'Maehyang' and 'Selva' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solid content under long-day and high temperature conditions in 2010. This cultivar was initially named 'Saebong No. 7' after examining its characteristics and productivity in summer culture from 2011 to 2014. After regional adaptability tests in 2015, 'Muha' was selected from Saebong No. 7 as an elite cultivar. The general characteristics of 'Muha' include semispreading type, elliptical leaf, and strength vigor in growth. The fruits are conical in shape, red in color. 'Muha' plants have 18.7 flower clusters, 8.7 more than 'Flamenco' plants. The fruit hardness of 'Muha' and Flamenco' was about the same. The number of fruits of 'Muha' was 37.2, which was 20 higher than that of 'Flamenco'. The marketable yield was 23,981 kg·ha^-1, 159% higher than 'Flamenco'. 'Muha' is suitable for north and highland area of the Southeast Asia as a high hardness and yield cultivar, because it showed continuous flowering habit under long-day and high temperature conditions.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.317-325
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• 2011

This study was conducted to examine the effect of supplemental lighting on the growth and yield of hydroponically grown sweet pepper (Capsicum annuum L. cv. sprit) under low levels of natural light in winter. The plants were treated with natural light only (control), 3-hour supplemental lighting before sunrise, after sunrise and after sunset with high pressure sodium (HPS, 400W). As the result of these three treatments, the supplemental lighting promoted photosynthesis in the low light intensity condition and particularly photosynthesis was more active right after sun rise in the morning, 1.5-$3.0{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$ comparing to those of supplemental lighting after sunset, 0.5-$1.5{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$. Transpiration rate and stomatal conductance sharply increased with supplemental lighting after sunrise then they decreased again after turning the lights off. Stomatal size was observed $32.2{\mu}m^2$ after supplemental lighting, whereas the size of the natural light was almost closed at $7.7{\mu}m^2$. The average plant height of sweet papper cv. spirit was 185 cm before sunrise, 188 cm after sunrise and 208 cm after sunset with supplemental lighting for 3hours while the control was 171 cm. With supplemental lighting a better number of fruit set per plant was measured 4.3 before and after sunrise, 3.7 after sunset but 2.6 in the control. Interestingly, there were no significant differences in the sugar content ($^{\circ}Brix$) degree between treatment of supplemental lighting, whereas slight differences between seasons were seen. The marketable fruit yield of sweet pepper (cv. spirit) was $116.0kg{\cdot}ha$ with supplemental lighting, whereas the control (natural light only) was $75.8kg{\cdot}ha$. Despite of spending electricity and depreciation cost, the economic analysis showed net income with supplemental lighting after sunrise was 51% higher than control treatment in cv. spirit.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.248-255
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• 2013

This study examined an automated irrigation technique by a frequency domain reflectometry (FDR) sensor for scheduling irrigation for tomato (Solanum lycopersicum L. 'Starbuck F1') cultivation aimed at avoiding effluent from an open hydroponic system with coir substrate containing different ratios of chip-to-dust (v/v) content. Specifically, the objectives were to undertake preliminary measurements of irrigation volumes, leachate volume, volumetric water content and electrical conductivity (EC) in the substrate, plant growth, fruit yield, and water use efficiency resulting from variation in chip content as an initial experiment. Commercial coir substrates containing different percentages of chips and dust (0 and 100%, 30 and 70%, 50 and 50%, or 70 and 30%), two-story coir substrates with different percentages of chips in the lower layer and dust in the upper layer (15 and 85%, 25 and 75%, or 35 and 65%), or rockwool slabs were used. The results showed that a negligible or no leachate was found for all treatments when plants were grown under a technique for scheduling non-drainage irrigation using a frequency domain reflectometry (FDR) sensor. Daily irrigation volume was affected by chip content in both commercial and two-story slabs. The highest plant growth, marketable fruit weight, and water-use efficiency were observed in the plants grown in the commercial coir slab containing 0% chips and 100% dust, indicating that the FDR sensor-auto-mated irrigation may be more useful for tomato cultivation in coir substrate containing 0% chips and 100% dust using water efficiently and minimizing or avoiding leachate and thus increasing yield and reducing pollution. Detailed experiment is necessary to closely focus on determining appropriate irrigation volume at each of irrigation as well as duration of each individual irrigation cycle depending on different physical properties of substrates using an automated irrigation system operated by the FDR sensor.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.428-438
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• 2014

Functional effects of cauliflower mushroom (Sparassis latifolia) have been magnified by various media and internal and external research papers, recently. So, optimum condition of wood chip particle size and cultivation method of high ${\beta}$-glucan content for bulk cultivation generalization of cauliflower mushroom farms researched. As a result, T7 (1~2 mm 25%, 2~4 mm 50%, over 4 mm 25%) media as mixed media of certain ratio of particle size, showed excellent growth at $11.5{\pm}1.0$ cm / 44 days. Also, production of fruit body found higher than control and marketable pileus part took 85% ratio. The ${\beta}$-glucan content at media composition condition showed 1.4~2.4 times higher content in stipe part than pileus part. Also, PCF300 medium found 59.5% highest ${\beta}$-glucan content in stipe part. While ${\beta}$-glucan content showed 33.0% low content in pileus part. Therefore it needed additional study that ${\beta}$-glucan content improved in pileus part. In conclusion, production of high ${\beta}$-glucan content cauliflower mushroom was possible by T7 condition (wood chip particle size: 1~2 mm 25%, 2~4 mm 50% and over 4 mm 25%, composition: corn powder, flour and 300 ppm yeast).

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.87-92
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• 2024

'Miha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2019. The 'Miha' cultivar originates from a 2014 cross between 'Monterey' and 'Saebong No. 3', both of which exhibited excellent ever-bearing characteristics, including continuous flowering and large fruits under long-day and high temperature conditions. This new cultivar was initially named 'Saebong No. 12' after examining its characteristics and productivity during summer cultivation between 2015 and 2019. After regional adaptability tests, 'Miha' was selected from 'Saebong No. 12' as an elite cultivar. The general characteristics of 'Miha' include intermediate, elliptic leaves, and strong growth. The fruits are conical and of a dark-red color. The number of leaves of 'Miha' was 21.9, which was 6.2 fewer than that of the control cultivar, 'Goha' with 28.1. The number of flower clusters of 'Miha' was similar to that of 'Goha'. The average fruit weight of 'Miha' was 13.4 g, which was 4.3 g heavier than that of 'Goha'. The fruit hardness of 'Miha' was 36.2 g·mm^-2, which was 10.1 g·mm^-2 harder than that of 'Goha'. The marketable yield of 'Miha' was 37,393 kg·ha^-1, 156% more than that of 'Goha' with 23,970 kg·ha^-1. Therefore, the new cultivar of ever-bearing strawberry 'Miha' is expected to be very popular in the export or bakery market because it is hard.