• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.58-63
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• 2000

Changes of yield and paeoniflorin content according to chemical control and harvest time were investigated. Peonies were harvested after four years from planting. Disease and pest control method was applied normally in first year. From second year to forth year we set two blocks and controlled them differently. In one, peonies were withered early under non-control condition. In the other which was controlled by spraying chemicals four time a year, top part withering was delayed. Harvest was taken four times top part withering was delayed. Harvest was taken four times: Jul. 25, Aug. 25, Sep. 25, and Oct. 25. In non-chemical, at harvest of Jul. 25, paeoniflorin content was highest and dry root weight was 1,126kg/10a which was little less than 1,177kg/10a of Aug. 25. In chemical control, dry root yield of Oct. 25. showed an increase of 33% over that of Jul. But paeoniflorin content in root at Oct. was lower than at Jul. or Aug. For high qualities and harvest yields of peony root, chemical control is necessary to maintain top part to late in Oct.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.427-435
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• 1991

Linear programming(LP) is a well-known method in optimizing timber harvest schedules. This paper describes a linear programming formulation of korean pine stands for timber harvest scheduling problems. Simulation technique and LP were applied to optimize the time and space distribution of the sustained yield for the 10-year forest management planning horizon. Growthfunction of korean pine stands in study area was derived with the yield table. This growthfunction was contained to the simulation model in estimating of changing stand volume conditions for the planning horizon. These estimated values were served as the basic data of LP model, and LP model was formulated with the maximum of periodical harvest volume calculated by the classical yield regulation method (Paulsen-Hundeshagen formula) and the maximum of periodical harvest area calculated for the normal age distribution. The timber harvest schedule was established periodically for each subcompartment of korean pine stands in experiment forest of College of Forestry in Kangweon National University with the here developed LP model.

• Proceedings of the Korean Society of Crop Science Conference
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• 1983.05a
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• pp.4-5
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• 1983

• Journal of the Korean Society of Tobacco Science
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• v.15 no.1
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• pp.75-89
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• 1993

Effect of the amount of fertilizer, plant density, and harvesting time on the production of tobacco leaf protein and fresh biomass was investigated. Flue-cured tobacco(M tabacum, L., cv. NC 82) seedlings were transplanted in the field dressed 200kg N per ha at 1$\times$105, 3$\times$105, 5$\times$105, 7$\times$105 plants per ha, and were harvested at the time when 6 and 10 weeks after transplanting, respectively. Harvest at 10 weeks after transplanting increased greatly number of leaves per plant and fresh weight of a plant, Precentage of senescent leaf weight, but significantly decreased fresh weight of a leaf and total protein contents g-1 fresh weight of leaf and stalk over the amount obtained from the harvest at 6 weeks after transplanting. Also, fresh leaf numbers of a plant, fresh weight of a leaf and of a plant, and total protein contents g-1 fresh weight of biomass were more decreased, but percentage of senescent leaf weight were remarkably increased under higher plant density. Therefore, it was seemed that harvesting at 6 weeks after transplanting under 1$\times$105 plant density per ha is more effective for producing higher yield of biomass and protein per plant than 10 weeks harvesting with 7$\times$105 population per ha. A trend was observed that biomass and protein yields per ha are positively correlated with plant population. Biomass yield per ha was the greatest at 7$\times$105 density(80.5t), but the peak of protein yield was at the near of 5$\times$105 population(2454kg as total protein) per ha on the regression curve. It was assumed that if tobacco plants are transplanted under 5$\times$105 plant density at the mid of May, and thereafter harvest at 6 weeks repeatedly during the growing season, it is possible to harvest 2~3 times per year, and to yield more 6.024kg of protein and over 140me1ric tons of fresh biomass ha 1 year 1 statistically in the korea tobacco growing regions.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.136-141
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• 2020

Background: The leaves of the goji berry (Lycium chinense Mill.) are used as raw materials in processing and by replace fruits to some extent. The reason is that the leaves are cheaper, however, betaine content is higher than in the fruits. These experiments were conducted to determine the planting density and cutting height for producing a large number of leaves. Methods and Results: The cultivar 'Myeongan' with many branches was used. When the shoot height reached 50 cm - 70 cm, harvesting was possible four times a year. The time to next harvest was approximately 38 days after regeneration of new shoots. Leaf quantity was in the order of 1st > 2nd > 4th > 3rd harvest. Insect damage occurred during the third harvest in late July and early August, therefore, eco-friendly control was necessary. The total yield was higher at the planting density 60 cm × 30 cm than that of 60 cm × 20 cm or 60 cm × 40 cm. The yield at cutting for shoot height of 60 cm was increased by 6.3 percent compared to that of 50 cm, At the cutting height of 70 cm, harvest was difficult owing to hardening of stems and thorns. Betaine content, an indicator component of goji berry, was not significantly different according to planting densities and cutting height. Conclusions: The ideal cutting period to produce leaves of goji berry for processing is when the shoots grow to approximately 60 cm, and the leaves can be harvested 4 times a year. The dried-leaf yield was highest at the planting density of 60 cm × 30 cm.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.2
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• pp.12-17
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• 2002

Since 1985, the growth rate of population of the world is over that of the food production. The cultivated land and the grain production rate are decreasing every year. Therefore, the most serious crisis which we will meet in the 21st century will be food shortage. In order to solve this desperate shortage of food, besides trying to produce more food, the technology of post-harvest, food processing, and food packaging should be developed to reduce and make the best use of the amount of the already produced agricultural products for which a lots of cost and labors were invested, but are being wasted during food distribution channel due to their undeveloped technology.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.25-30
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• 2010

This experiment was carried out to investigate the effect of planting times on the growth and yield of artichoke (Cynara scolymus L.) in non-heated greenhouse in Jeju Island ($33^{\circ}28.110N,\;126^{\circ}31.076E$), Korea. Five transplanting dates (from Feb. 25 to Apr. 30) of the first half of the year and six transplanting dates (from July 30 to Dec. 15) of the second half of the year were compared. In the spring cycle, most of the flower buds emerged from May to June, and the emergence was slightly earlier in 'Imperial Star' than in 'Green Globe'. The earliest harvest on June 16 was 'Imperial Star' which was planted on Feb. 25. The highest yield of 856 kg/10a was observed in 'Imperial Star' which was planted on Feb. 25. Transplanting of the first half of the year, it was impossible to harvest in the same year when the planting was done after April 15 since the flower buds were not emerged. The flower buds emerged from late Feb. to middle April of the following year in the all planting times of the second half of the year. It was possible to harvest the first time in early April. The highest yield was 2,127 kg/10a in 'Green Globe' which was planted on July 30, and the yields decreased as the planting times were delayed. In the comparisons of planting times of artichoke, it would be recommendable to plant artichoke on Feb. 25 for the same year harvest and in July 30~Oct. 15 for the following year harvest in Jeju Island non-heated greenhouse cultivation.

• 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 Ginseng Research
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• v.13 no.1
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• pp.14-18
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• 1989

The graminicides fluazifop-p-butyl and sethoxydim effectively controlled annual grass weeds in 1,2 and year old ginseng crops during a 2 year study. Ginseng plants in the graminicide treated plots showed an early senescence of the shoots ; and at harvest the average root weight (g/root) and yield (kg/m) were slightly lower in these plants than in the untreated check plots. Roots of the graminicide treated plots remained viable to regenerate shoots. The greenhouse study indicated that shoot growth and seed development in ginseng plants were more sensitive to the graminicide treatment than the roots.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.510-517
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• 2014

The purpose of this study was to analyze microbial hazards for cultivation environments and personal hygiene of strawberry and tomato farms at the growth and harvesting stage. Samples were collected from thirty strawberry farms and forty tomato farms located in Korea and tested for Staphylococcus aureus and Bacillus cereus. To investigate the change in the distribution of the S. aureus and B. cereus, a total of 4,284 samples including air born, soil or medium, mulching film, harvest basket, groves and irrigation water etc. were collected from eight strawberry farms and nine tomato farms for one year. As a result, total S. aureus and B. cereus in all samples were detected. Among the total bacteria of strawberry farms, S. aureus (glove: $0{\sim}2.1Log\;CFU/100cm^2$, harvest basket: $0{\sim}3.0Log\;CFU/100cm^2$, soil or culture media: 0~4.1 Log CFU/g, mulching film: $0{\sim}3.8Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}2.8Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.8Log\;CFU/100cm^2$, soil or culture media: 0~5.3 Log CFU/g, mulching film: $0{\sim}4.5Log\;CFU/100cm^2$) were detected in all samples. The total bacteria of tomato farms, S. aureus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}5.0Log\;CFU/100cm^2$, soil or culture media: 0~6.1 Log CFU/g, mulching film: $0{\sim}4.0Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.3Log\;CFU/100cm^2$, soil or culture media: 0~5.9 Log CFU/g, mulching film: $0{\sim}4.7Log\;CFU/100cm^2$) were detected in all samples. The contamination of S. aureus and B. cereus were detected in soil, mulching film and harvest basket from planting until harvest to processing, with the highest count recorded from the soil. But S. aureus and B. cereus were not detected in irrigation water samples. The incidence of S. aureus and B. cereus in hydroponics culture farm were less than those in soil culture. The amount of S. aureus and B. cereus detected in strawberry and tomato farms were less than the minimum amount required to produce a toxin that induces food poisoning. In this way, the degree of contamination of food poisoning bacteria was lower in the production environment of the Korea strawberry and tomato, but problems can be caused by post-harvest management method. These results will be used as fundamental data to create a manual for sanitary agricultural environment management, and post-harvest management should be performed to reduce the contamination of hazardous microorganisms.