• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.69-75
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• 2005

The storability of chicon was compared by packing it with PE box, wrap, LDPE (low density polyethylene) film that was 25 and 50um thickness, respectively and storing at 1 and $10^{\circ}C$ under light and dark conditions. The visual quality depending on dehydration was deteriorated at more than $2\%$ weight loss during storage. In packing treatments, chicon packed with PE box lost fresh weight to $3\%\;at\;10^{\circ}C\;and\;2\%\;at\;1^{\circ}C$, while non- penetrated film treatment, wrap, 25 and 50um thickness LDPE film, showed less than $1\%$ weight loss. The carbon dioxide concentration in package was $3\~4\%\;in\;50{\mu}m$ LDPE film at $1^{\circ}C\; and\;25um$ LDPE film at $10^{\circ}C$. The ethylene concentration in 50um LDPE film at $1^{\circ}C\;and\;25{\mu}m$ LDPE film at $10^{\circ}C$ was approximately 0.3 ppm and 0.5 ppm, respectively. Chiton stored in dark condition didn't turn to green, but it fumed green only in 3 days at $10^{\circ}C$ and in 6 days at $1^{\circ}C$ under light condition. The greening of chicon was less, the packing materials was thicker. The chlorophyll content represented the degree of greening showed less at $1^{\circ}C$ then at $10^{\circ}C$. The coefficient of correlation(r) between chlorophyll content and carbon dioxide concentration in package was 0.926 at $1^{\circ}C$ and 0.997 at $10^{\circ}C$. The visual quality except greening of packed chicon was maintained at $1^{\circ}C$ better than $10^{\circ}C$, and it was shown highest grade packed with $50{\mu}m$ LDPE film at $1^{\circ}C$ and packed with 25um LDPE film at $10^{\circ}C$. The vitamin C content in packed chicon was kept higher at $1^{\circ}C$ on storage temperatures, and 25um and 50um LDPE film on packing materials. According to these results, it can be proper condition for storage and marketing of chicon that 50um LDPE film at $1^{\circ}C$ and 25um LDPE film at $10^{\circ}C$. And dark condition is necessary to store chicon because it should turn green under tiny light condition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.223-231
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• 2017

This study was conducted to determine the impact of elevated temperature based on climate change scenario on growth and bulb quality of extremely early-maturing onion (Allium cepa L. cv. Singsingball) in the temperature gradient tunnels. There were treated with 3 groups, one is a control group (ambient temperature, mean temperature at $9.8^{\circ}C$), another ambient temperature $+2^{\circ}C$ (mean temperature at $12.0^{\circ}C$), and the other ambient temperature $+5^{\circ}C$ (mean temperature at $14.3^{\circ}C$). Compared with the control, plant height, neck diameter, leaf area, top fresh weight and dry weight were significantly increased at ambient $+2^{\circ}C$ temperature. Bulb diameter and bulb weight was highest at ambient $+2^{\circ}C$ temperature (mean temperature at $12.0^{\circ}C$) during the growth period. Bulb/neck diameter ratio, over 2.0 a good indicator of development of bulb, increased rapidly at ambient $+2^{\circ}C$ temperature. This result suggests that extremely early-maturing onion (Allium cepa L. cv. Singsingball) could maintain the higher productivity and bulb quality at ambient $+2^{\circ}C$ temperature. On the contrary, $5^{\circ}C$ higher than atmospheric temperature shows negative effects on yields under a future climate change scenario.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.110-116
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• 2019

This study was conducted to determine the effects of a pre-planting fertilizers with various $NH_4{^+}:NO_3{^-}$ ratios in a coir dust:peatmoss:perlite (3.5:3.5:3.0, v/v/v) medium on the growth of hot pepper (Capsicum annuum L. cv. Nokkwang) plug seedling. Nitrogen levels were fixed to $300mg{\cdot}L^{-1}$ and the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, and 100:0. The 50-cell trays were filled with treatment media containing pre-plant fertilizers, then seeds were sown. After seeds were germinated, the trays were moved to greenhouse and seedlings were feed with 13-2-13 and 20-9-20 fertilizers, alternatively. The changes in pH and EC were measured every week and soil solution for nutrient concentrations were analyzed in week 0, 3, and 7. The measurements of seedling growths as well as analysis of tissue nutrient contents were also conducted in week 7. The varied $NH_4{^+}:NO_3{^-}$ ratios did not influence on the pHs of root media after incorporation of pre-planting fertilizers, but the ECs were heightened as proportion of $NH_4{^+}$ to $NO_3{^-}$ were elevated. During the raising of seedlings, the pHs rose over time in the treatments of 0:100 and 27:73 ($NH_4{^+}:NO_3{^-}$). The concentrations of all macro-elements in root media decreased gradually as seedlings grew in all treatments. The seedling growths 7 weeks after seed sowing were the highest in the treatments of 27:73 and 50:50 ($NH_4{^+}:NO_3{^-}$) and those became worse in the treatments of higher $NH_4{^+}$ ratios than 73%. In terms of inorganic element contents based on the dry weight of above ground tissue, the treatment of 0:100 showed the lowest content of Ca, Mg, Na, Cu, Mn, and Zn. Based on the results, it is desired that $NH_4{^+}$ ratio in pre-planting fertilization is maintained to be 50% or less for the raising of hot pepper plug seedlings.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.148-156
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• 2023

This study was conducted in an indoor cultivation room and chamber where environmental control is possible to investigate the effect of temperature and irrigation interval on photosynthesis, growth and growth analysis of potted seedling cucumber. The light intensity (70 W·m^-2) and humidity (65%) were set to be the same. The experimental treatments were six combinations of three different temperatures, 15/10℃, 25/20℃, and 35/25℃, and two irrigation intervals, 100 mL per day (S) and 200 mL every 2 days (L). The treatments were named 15S, 15L, 25S, 25L, 35S, and 35L. Seedlings at 0.5 cm in height were planted in pots (volume:1 L) filled with sandy loam and treated for 21 days. Photosynthesis, transpiration rate and stomatal conductance at 14 days after treatment were highest in 25S. These were higher in S treatments with a shorter irrigation interval than L treatments. Total amount of irrigation water was supplied evenly at 2 L, but the soil moisture content was highest at 15S and lowest at 25S > 15L > 25L, 35S and 35L in that order. Humidity showed a similar trend at 15/10℃ (61.1%) and 25/20℃ (67.2%), but it was as high at 35/25℃ (80.5%). Cucumber growth (plant height, leaf length, leaf width, chlorophyll content, leaf area, fresh weight and dry weight) on day 21 was the highest in 25S. Growth parameters were higher in S with shorter irrigation intervals. Yellow symptom of leaf was occurred in 89.9% at 35S and 35L, where the temperature was high. Relative growth rate (RGR) and specific leaf weight (SLA) were high at 25/20℃ (25S, 25L), RGR tended to be high in the S treatment, and SLA in the L treatment. Water use efficiency (WUE) was high in the order of 25S, 25L > 15S > 15L, 35S, and 35L. As a result of the above, the growth and WUE were high at the temperature of 25/20℃.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.385-391
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• 2013

In this study, the availability of slurry composting and biofiltration (SCB) solution as an alternative for synthetic nutrient solution was determined by monitoring the growth, fruit yield, and fruit quality of cherry tomato (Solanum lycopersicum L. 'Unicon'). Treatments for nutrient solution were consist of SCB 1/2N, 1N, 2N, and commercial nutrient solution 1N (CNS 1N) based on nitrogen concentration (218.32 $mg{\cdot}L^{-1}$) of cherry tomato nutrient solution (control 1N). All nutrient solution including SCB solution (440~520 mL per day) was supplied to rock wool medium using a timer. After 31 days of transplanting, fresh and dry weights of shoots, leaf area, plant height, stem diameter, SPAD value and number of node were measured. After measuring growth characteristics of tomato plants, total fruit yield, ratio of marketable fruit yield, fruit weight, total soluble solids content, total acidity, total phenolic concentration, and antioxidant capacity were determined once a week for 7 weeks. As a result, among the SCB treatments, SCB 1/2N was similar to control 1N and CNS 1N in terms of fresh and dry weights of shoots, leaf area, stem diameter, number of node, and SPAD value. Increased N concentration of SCB inhibited the growth of tomato plants. Total fruit yield of SCB 1/2N was 47% of that of control 1N which showed the best result. Percentage of marketable fruit yield in SCB 1/2N was about 58%. Soluble solids contents, total acidity, total phenolic concentration and antioxidant capacity was the highest in SCB 2N and the other treatments were not shown any difference. Blossom-end rot rarely occurred in control 1N and CNS 1N while SCB treatments without Ca induced the physiological disorder of 7~19%. In conclusion, SCB 1/2N was good for the vegetative growth of cherry tomato plants but reduced yield and quality of fruit compared with control 1N and CNS 1N. Thus, it is possible to apply SCB solution to grow cherry tomato plants hydroponically but in the consideration of fruits yield and quality additional supply of several minerals would be required.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.447-455
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• 2011

To investigate the effects of the improvement of postharvest quality on fresh tomato, antimicrobial microperforated (AMP) films were prepared and their antimicrobial abilities were observed. AMP films were made by coating different types of natural antimicrobial agents such as cinnamon, clove, and clary sage essential oils into microperforated (MP) films. Cinnamon essential oil of 10% (v/v) has proven to be very effective as inhibitor of the mold growth on tomato, compared to the clove and clary sage essential oils. Quality changes of fresh tomatoes packed using the natural AMP films (AMP10 and AMP30) and MP films (MP10 and MP30) during storage were evaluated. Total microbial growth, weight loss, firmness, lycopene content, and decay rate as the major quality parameters were monitored over 9 days at $15^{\circ}C$. The oxygen transmission rates and mechanical properties between the natural AMP and MP films were also compared. There was no significant difference in change of oxygen transmission rate, tensile strength and elongation between the AMP and MP films. For storage studies, the freshness of tomato packaged in AMP30 film was higher than that in OPP film (the control), MP10, MP30, and AMP10 films. Especially, AMP30 film exhibited high efficiency compared to the control for tomato decay during storage periods. Based on the results, the microperforation and antimicrobial properties of the packaged films may significantly affect the maintenance of an optimum gas composition within the package atmosphere for increasing the storage life and quality of produce. They were also effective on the inhibition of microbial growth by controlled release of antimicrobial agent at an appropriate rate from the package into the tomato. Natural antimicrobial agent coating microperforated films could use potential functional package as a method of extending the freshness of postharvest tomato for storage.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.81-86
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• 2000

The objective was to develop herbicides for liquorice (Glycyrrhiza uralensis), one of most important ingredients of herbal medicine in Korea. Soil-applied herbicides, pendimethalin at 1,585 g a.i. $ha^{-1}$, simazine at 1,000 g a.i. $ha^{-1}$, alachlor at 5 g a.i. $ha^{-1}$, metolachlor at 1,600 g a.i. $ha^{-1}$, and ethalfluralin at 1,050 g a.i. $ha^{-1}$ provided greater control of hairy crabgrass and barnyardgrass (> 60%) but less control of Abutilon avicennae and Fagopyrum esculentum under growth chamber conditions. Of tested soil-applied herbicides, pendimethalin and simazine showed slight injury to liquorice (<17%). In the field experiment conducted in Chunchon, pendimethalin and simazine provided greater control of weeds: total fresh weight of weeds in control plots was 187 g $m^{-2}$, while those in both herbicides-treated plots were nil. Fresh weights of liquorice seedlings in pendimethalin- and simazine-applied plots, however, were not different from those in control plots. Foliar-applied herbicides, such as dicamba at 964 g a.i. $ha^{-1}$, 2,4-D at 280 g a.i. $ha^{-1}$, mecoprop at 2,500 g a.i. $ha^{-1}$, flazasulfuron at 75 g a.i. $ha^{-1}$, imazaquin at 800 g a.i. $ha^{-1}$, bentazon at 1,600 g a.i. $ha^{-1}$, and pyribenzoxim at 30 g a.i. $ha^{-1}$ reduced the growth of liquorice seedlings and provided moderate to total damage. Overall results show that pendimethalin and simazine appears to be effective herbicide candidates for liquorice.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.13-20
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• 2015

This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.27-32
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• 1994

These studies were Conducted to survey cultivation methods, and to analyze soil chemical properties for stable production of Aralia continentalis K., a promising medicinal crop, in the main producting districts. Aralia continentalis K. was cultivated with planting budstocks in distances of $90cm{\times}60cm$ for 3~4 years in the same field, and application rates were N 10~31 kg/10a and P, K 8~17/10a using inorganic fertilizer, that is compound fertilizer(21-17-17) for basal dressings and urea for topdressings. Most of all, the soil surveyed was coarse loamy class which was well drained and soil depth is 50~150cm in the valleys. Soil pH was low, and content of organic matters and av. $P_2O_5$ was abundant but that of exchangeable cation such as Ca, Mg, K was deficient. The relationship between growth characteristics and weight of fresh root was positive correlation in the order of No. of root, stem width, No. of node and branch, plant height and root width. On the path coefficiant analysis, the relationship between content of soil K, Ca and root yield was more apparent than other chemical properties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.129-136
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• 1990

In the present report, two experiments were carried out with the purposes of knowing the differences of response among forage species to growing period and potassium level in culture solution, and investigating possible relation of the responses with occurence of grass tetany on grazing pasture. The results were as follows; (1) At 25 days after germination, fresh weight of top part as well as the sum of top and root parts of the forages increased rapidly. (2) Italian ryegrass was the highest in potassium (K) content but the lowest in magnesiurn(Mg) content among the three gramineous forages, while tall fescue showed the opposite result to it. And orchardgrass was intermediate of the two forage species (Experiment 1). (3) The K contents of forages generally increased, while Mg content became lower with the increase of K level in culture solution. The highest K contents of Italian ryegrass and orchardgrass were more than 3 times of the lowest values. The K contents of alfalfa and tall fescue increased in the narrower range. The decreases of Mg content of Italian ryegrass and orchardgrass were significant in the ranges of 5ppm to 25 or 50ppm KzO, while the content of the leguminous forages and tall fescue decreased up to 1000 level. (4) Fresh yield, water content and K content of the forages were significantly increased with the increase of K20 application levels up to 25 or 50ppm. (5) The K concentration of forage on a tissue water basis was higher at 50ppm than that at 5ppm $K_20$ level, especially for Italian ryegrass and orchardgrass with the value of 2.6times and 2.5times, respectively. However, the K concentration (tissue water) of leguminous forages increased gradually up to the level of lOOOppm (Experiment 2). It is suggested from the results that rapid changes of water content, Mg content and K concentration (tissue water) may occur to forage on a grazing pasture, when both growing period and K level in the soil affect the changes simultaneously. Under such conditions, plant water especially in Italian reyegrass and orchardgrass can function as toxic material to grazing ruminants.