• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.27-33
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• 2015

High temperature stress in summer season at plastic house is a limiting factor for tomato fruit set and yield. This study was performed to assess the effects of gibberellic acid ($GA_3$) and 2,4-Dichlophenoxy acetic acid (2,4-D) spray on fruit set, yield, and quality of tomato cv. 'Adoration'(Enza Zaden Co., Ltd.) under the plastic house in Hwacheon, 2011. Four concentrations (0-, 5-, 10- and $15mg{\cdot}L^{-1}$) of $GA_3$, and three concentrations (0-, 5- and $10mg{\cdot}L^{-1}$) 2,4-D were sprayed in early flowering of tomato in the plastic house, and fruit set, yield and quality characters were observed. The results showed that spray of $10mg{\cdot}L^{-1}$ $GA_3$ significantly increased the fruit set by 14.2% than unsprayed. The spray of $GA_3$ significantly increased the marketable fruit number, fruit weight, and yield. The spray of 2,4-D on blossoms significantly affected the fruit set percentage, fruit weight, marketable fruit weight and yield, and the highest fruit set observed as 62.5% in combined spray of $GA_3$ and 2,4-D at each $5mg{\cdot}L^{-1}$. Fruit size and total soluble solids significantly varied with the concentrations of $GA_3$ sprayed. The result indicates that the spray of $10mg{\cdot}L^{-1}$ $GA_3$ and $5mg{\cdot}L^{-1}$ 2,4-D can be more economic and effective to increase the fruit set, and yield in tomato under high temperature condition in plastic house.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.73-80
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• 2014

Postharvest insect pest control is necessary for agricultural industry including domestic consumer markets and exporting products to meet quarantine issue. Especially, the organic or environmentally friendly agricultural products do not fit to the traditional chemical postharvest treatments mostly using methyl bromide. As an alternative, a physical treatment called CATTS (controlled atmosphere and temperature treatment) has been developed to control various insect and mite pests on apple and several stone fruits. This study was designed to determine the CATTS conditions to control the oriental fruit moth, Grapholita molesta, which is restricted in exporting the infested apples. To apply CATTS on this insect pest, the most heat-tolerant stage was determined. Among the immature stages locating on the fruits, the fifth instar larvae were the most tolerant to $44^{\circ}C$ for 20 min. The ramping rate (the time to increase chamber temperature from $25^{\circ}C$ to $46^{\circ}C$) was positively correlated with the CATTS efficiency under 15% $CO_2$ and 1% $O_2$. After the ramping step, the duration of CATTS was positively correlated with CATTS efficiency. In addition, the CATTS efficiency was highly dependent on the fruit internal temperature at $44^{\circ}C$. From all these parameters, we developed a standard protocol yielding 100% control efficiency of CATTS against apples infested by 4,378 larvae including 2,104 fifth instar individuals.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.349-355
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• 2018

This study was aimed at predicting the yield of paprika (Capsicum annuum L.) through analyzing the growth characteristics, yield pattern and greenhouse environment. In the greenhouse of the Gyeongnam area (667 m above sea level), the red paprika 'Cupra' and the yellow paprika 'Fiesta' were grown from July 5, 2016 to July 15, 2017. The planting density was $3.66plants/m^2$ and attracted 2 stems. During the cultivation period, the average external radiation of the glasshouse was $14.36MJ/m^2/day$ and the internal average temperature was controlled as $20.1^{\circ}C$. After 42 weeks of planting, the growth rate of 'Cupra' was 7.3 cm/week and that of 'Fiesta' was 6.9 cm/week. The first fruit setting of 'Cupra' appeared at 1.0th node and 'Fiesta' at 2.7th node. The first harvest of 'Fiesta' was 11 weeks after planting and 'Fiesta' was 14 weeks. Comparing the yield per 10 a until the end of the cultivation in July, 'Fiesta' was 19,307 kg, which was 2.4% higher than that of 'Cupra'. And the fruit weight ratio of over 200 g of 'Cupra' was 27.7% which was 7.7% higher than that of 'Fiesta'. The average required days to harvest after fruit setting of 'Cupra' was 72.6 days and 'Fiesta' was 63.8 days. According to the relationship between the average required days to harvest and the cumulative radiation (during from fruit setting to harvest), the more radiation increases the less required days to harvest increases after February. In terms of yield, 'Cupra' increased in yield as the cumulative radiation increased, while 'Fiesta' showed an irregular pattern. Cumulative radiation from fruit setting to harvest was negatively correlated with required days to harvest after February in both cultivars. But in relation to yield, there were difference between 'Cupra' and 'Fiesta'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.203-209
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• 2009

Yield monitoring is one of a precision agriculture technology that is used most widely. It is spatial variability analysis of yield information that should be attained with yield monitoring system development. This experiment was conducted to evaluate spatial variability of yield and grain moisture content in rice paddy field, and their relationships to rice productivity. It is necessary to minimize sampling interval for accurate yield map making or to control cutting width of rice combine. Considering small rice plots such as $0.2{\sim}0.4$ ha, optimum size of sampling plot was below 15 m more than 5 m in with and length. In variable rate treatment field, average yield was similar, but yield variation was reduced than conventional field. Gap of yield by another plot in same field was bigger than half of average yield than yield variation was significantly big. Therefore yield measuring flow sensor must be able to measure at least 300 kg/10a more than 1000 kg/10a. Variation of moisture content in same field was not big and spatial dependance did not appear greatly. But, variation between different field is appeared difference according to weather circumstance before harvesting. Change of spatial dependence of yield was not big, because of field variation of moisture content is not big.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.12-17
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• 2002

Tn establish the criteria for appropriate seedling production method in the summer, the effect of container size and seedling age on the growth and yield were evaluated with tomato. The seedling quality was higher when seedlings were grown polyethylene in 9cm pots than in 72 cell plugs. Seedling quality increased with increase in seedling age in polyethylene pots, whereas seedling age did not affect seedling quality in plug trays. Fruits matured earlier on plants started from pot-grown transplants for a long duration than with plug tray-grown transplants for a shorter duration. Not only total yield in 4 months, but the early yield in the first 2 months, was higher with pot-nursed transplants than with plug tray-nursed transplants. With pot-grown transplants, The early yield in initial 2 months was the lowest in 25 day-old transplants, whereas there was no significant differences between 35- and 45-day-old transplants. Seedling age did not affect the cumulative yield for 3 months after the first harvest. With plug tray-grown transplants, the cumulative yield tar initial 3 months was the highest in plants grown for 35 days in the nursery, followed by 25 day and 45 day. However, there were no significant differences among seedling ages in the total yield.

• Food Science and Preservation
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• v.9 no.4
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• pp.357-361
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• 2002

This study was carried out to understand the problems, and find out the solution of post - Harvest related procedures for barley in Korea. Consecutive post - harvest procedures in harvesting, drying, milling, packaging and marketing methods were collaborately surveyed at Bujeok (Chungchongnamdo) and Kunsuh (Cholanamdo) agricultural cooperative federation where Chalssalbori (waxy barley) and Ssalbori (non waxy barley) were collectively cultivated in a group farming area, respectively. An early harvesting and relatively short harvesting period within 15 to 20 days to transplanting rice plants as a succeeding crop lead to produce undergrade barley and 2 to 3％ harvesting loss were considered as the problem that should be improved. In drying of barley, wide moisture content range of harvested barley among the different farmers and cultivation land was made difficult barley drying unifomly when they were dried in same dryer and drying temperature was slightely higher with 50 to 70$\^{C}$ than that of optimum temperature (under 50$\^{C}$) fer barley drying for producing the high quality barley. Dried barley packaged in ton-bag or 3P bag and put into the rectangular grain bin were stored in ambient temperature warehouse and milled for marketing through whole you. The physico-chemical properties and taste of stored barley were fairly maintained until May next year.

• Korean journal of applied entomology
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• v.49 no.1
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• pp.37-42
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• 2010

As an environment-friendly phytosanitary measure, CATTS (controlled atmosphere temperature treatment system) has been developed to kill several quarantine insect pests infesting subtropical agricultural commodities. This study tested any possibility to apply CATTS to apples to effectively eliminate the peach fruit moth, Carposina sasakii, which has been regarded as a quarantine insect from the imported countries. When the larvae of C. sasakii were directly exposed to $46^{\circ}C$ (an installed lethal temperature of CATTS), they showed a median lethal time at 14.66 min. Addition of high carbon dioxide to the temperature treatment enhanced the thermal limit susceptibility of C. sasakii to $46^{\circ}C$. CATTS device was constructed to automatically control $CO_2$ concentration and temperature with real-time monitoring both in the chamber and in the fruit. The larvae internally infesting apples were tested using the CATTS device and showed 100% lethality after 60 min exposure to a treatment of $46^{\circ}C$ under 15% $CO_2$ in the chamber. Relatively long exposure may be due to the deviation between the ramping temperature ($0.35^{\circ}C$/min) of the chamber and the ramping temperature (0.12-$0.23^{\circ}C$/min) inside apple fruit, where the tested larvae were located. This study suggests a possibility that CATTS can be applied as a quarantine measure to kill the larvae of C. sasakii locating inside the apples.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.404-410
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• 2012

This study was conducted to examine effects of harvest time (09:00 vs. 14:00), precooling at $4^{\circ}C$ vs. no precooling, and storage temperature (4 vs. $8^{\circ}C$) on the storage life of 'Maehyang' strawberry fruits for export. Fruits at a 60% ripe stage were harvested from a commercial greenhouse in Gyeongsangnamdo, Jinju on May 4, 2010. Fruits were precooled by a forced draft cooling for three hours, transported for about 30 minutes and then stored, immediately. Small precoolers set in the farm were used for precooling. Fruits were placed in constant temperature chamber (4 or $8^{\circ}C$) after packaging using PVC wrap and a cardboard box. Fruits were examined for their changes in weight, hardness, Hunter color values, soluble solids content (SSC), and incidence of gray mold (Botrytis cinerea) during storage at a two days interval from May 6 to May 14, 2010. Hardness and SSC decreased as the ripening stage progressed. The Hunter's 'L' and 'a' value of fruit color decreased as time passed. Also, fresh weight decreased during storage at all temperatures. Soft rot appeared on epidermal tissues and followed by gray mold. Incidence of gray mold was greater at $8^{\circ}C$ storage temperature than in $4^{\circ}C$ storage temperature. However, no difference by the harvested time and precooling. The results indicate that effectiveness for keeping the freshness was best achieved by precooling at $4^{\circ}C$ and storage at $4^{\circ}C$, respectively.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.183-187
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• 2021

Appropriate pruning is very important for southern highbush blueberries cultivated in a heated plastic house to control their severe crowding within the bush canopy after harvest. Pruning treatments at different times were evaluated to find out an appropriate pruning time to southern highbush 'Scintilla' cultivation with heating. Seven-year-old (2018) bushes, grown in 180-L containers, were summer-pruned on May 20 (35-39 days after harvest) and June 20, or dormant-pruned on December 20 (5 days before flowering), consecutively in both 2018 and 2019 removing 30% of the total woods. May pruning activated occurrence of shoots the following years, increasing number of shoot by 17 to 49% and total shoot length by 18 to 32% compared with those of the dormant pruning. Fruit characteristic was not significantly affected by different pruning times the previous year. The first year pruning treatment did not influence the yield the following year, but the second year consecutive May pruning significantly increased yield per bush by 7% compared with the dormant pruning. The results indicated that summer pruning in May could be favorable to promote shoot growth and to maintain stable yield.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.324-332
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• 2010

This experiment was carrid out to develop a culture method by sequential highland-lowland cultivation for year-round production of fresh leaves in Ligularia stenocephala. Rootstocks of Ligularia stenocephala cultivated in Daegwallyeong openfield were digged up on late October 2007 and then stored in $-2^{\circ}C$ refrigerator. The rootstocks were monthly transplanted in protected greenhouse in Gangneung from November 2007 to June 2008 for lowland cultivation, and also they were monthly transplanted in rainshelter in Daegwallyeong from June to August 2008 for highland cultivation. The early growth of Ligularia stenocephala transplanted on January 2008 was faster. Most plant of Ligularia stenocephala regardless of transplanting time of rootstock grew over 30cm at the time of first harvesting of leaves till May, while the yield decreased during the summer season. The average plant height of Ligularia stenocephala transplanted on July and August in Daegwallyeong highland was lower than that cultivated in Gangneung lowland during spring season. Using of rootstock stored made it possible to produce in highland from Apr. to Oct. during summer season, and also to produce in lowland from Nov. to May next year. Therefore, the results indicates that sequential highland-lowland cutivation by using of stored rootstock will be capable of yearround production of fresh leaves in Ligularia stenocephala.