• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.327-338
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• 2020

In recent years, the temperature of Korea has been rapidly increasing due to global warming. Over the past 40 years, the temperature of Korea has risen by about 1.26℃ compared to that in the early 1980s. By region, the west region of the Gangwon Province was the highest at 1.76℃ and the Jeonnam Province was the lowest at 0.96℃. As the temperature continues to rise, it is expected that the rice yield will decrease in the future using the current standard cultivation method. As a result of global warming, the periods in which rice cultivation could be possible in regions each year has increased compared those to the past, showing a wide variety from 110 days in Taebaek to 180 days in Busan and Gwangyang. In addition, the transplanting time was delayed by 3-5 days in all regions. The average annual yield of rice showed an increasing trend when we analyzed the average productivities of developed varieties for cooked rice since the 1980s, especially in the early 1990s, which showed a rapid increase in productivity. The relationship between the average temperature at the time of development and the rice yield was divided into the periods before and after 1996. The higher the average temperature, the lower the yield of the developed varieties until 1996. However, since 1996, the increase in the average temperature did not show a trend in the productivity of the developed varieties. The climate change adaptability of developed rice varieties was investigated by analyzing the results of growing crops nationwide from 1999 to 2016 and the change in the annual yields of developed varieties and recently developed varieties as basic data to investigate the growth status of the crops in the country. As a result of annual comparisons of the yields of Taebongbyeo (2000) and Ungwangbyeo (2004) developed in the early 2000s for Odaebyeo, which was developed in the 1980s, the annual yields were relatively higher in varieties in the 2000s despite the increase in temperature. The annual yields of Samgwangbyeo (2003) and Saenuribyeo (2007), which were recently developed as mid-late-type varieties, were higher than those of an earlier developed variety called Chucheongbyeo, which was developed in the 1970s. Despite the rapid increase in temperature, rice cultivation technology and variety development are well adapted to climate change. However, since the biological potential of rice could reach its limit, it is necessary to develop continuous response technology.

• Research in Plant Disease
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• v.16 no.1
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• pp.106-108
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• 2010

This survey was conducted to investigate effect of covering with polyvinyl ($120{\times}90cm$) on incidence of Phytophthora blight and anthracnose and growth. Early growth of pepper plant was superior when was covered with polyvinyl after planting. Incidence of anthracnose and Phytophthora blight was lower 26.9% and 60.3% in covering system than those in conventional culture system, respectively. A yield of dried red pepper was more 48.5% in cultured with covering system than that in conventional culture system.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.304-310
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• 1997

In greenhouse, a mixed solution of Mn-54, Co-60, Sr-85 and Cs-137 was applied to the soil of culture boxes 2 days before sowing cucumber and at 4 different times during its growth for measuring their transfer factors (TFs) for fruit and migration in soil. TFs varied with radionuclide, application time and harvest time by factor of up to about 60. Variations in TFs with application time showed different patterns among radionuclides. TFs decreased on the whole in the order of Sr-85 > Mn-54 > Co-60 > Cs-137. TFs of Mn-54, Co-60 and Cs-137 mixed with topsoil before sowing were a little higher than those for the soil-surface application made at an early growth stage while no difference in Sr-85 TF was found. After harvest, soil concentrations of the radionuclides applied at an early growth stage were examined. They decreased with increasing soil depth and 80${\sim}$99% of the radioactivity remained in the top 3cm. Soil pemeation of the radionuclides migration decreased in the order of Sr-85 > Mn-54 > Co-60 > Cs-137. The present data can be utilized in estimating radionuclide concentration in cucumber fruit, taking proper measures for its harvest and consumption and designing the best way of soil decontamination following an radioactive deposition during the cucummber growing season.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.72-72
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• 2020

곤달비(Ligularia stenocephala)는 쌍떡잎식물, 국화과의 다년생 초본식물로서 한국·일본·타이완·중국 등에 분포하며, 우리나라에는 전남 홍도가 특산 자생지라고 하며 주로 강원도, 경북 경주, 전북 남원 등지에서 재배되고 있다. 곤달비는 어린 부분을 생채, 데친 나물, 국거리, 튀김, 묵나물로 식용한다. 특수 성분으로는 Isopropenyl, dimethoxybenzofuran, Liguhodgsonal, Ligujapon, Ligularinone A, Ligularinone B 등이며 신경을 안정시키는 진정작용, 진통억제, 정기를 보익하고 허약함을 보하는 기능이 있고, 한방에서는 뿌리가 신경통, 유종(乳腫) 등에 쓰인다. 곤달비는 주로 시설하우스나 노동력이 많이 드는 임간에서 재배되어 생산 단가가 높아 소비활성화를 위한 가공제품을 생산하기가 힘들다. 본 연구는 곤달비를 저비용 대량 생산을 위한 노지재배 생력화 재배기술을 확립하고자 시험을 수행하였다. 2019년 4월부터 2020년 11월까지 전라북도 농업기술원 허브산채시험장(해발 500m)에서 곤달비 노지재배를 대상으로 이랑폭 90cm, 120cm, 180cm 3처리구로 하여 시기별 생육특성, 수량성, 생리장해 등을 조사하였다. 2019년 4월 정식 후 활착률은 180cm 처리구에서 92.1%로 가장 높았고 120cm 처리에서 90.2%로 가장 낮았으며, 생존율 또한 180cm 처리구에서 87.2%로 가장 높았고 120cm 처리에서 84.4%로 가장 낮았다. 생육특성 결과 1차년도에는 초장, 엽장, 엽폭은 생육 초기부터 후기까지 90cm 처리구에서 가장 높았고, 엽수는 120cm 처리구에서 가장 많았다. 2차년에는 180cm 처리구에서 초장 61.2cm, 엽장 32.6cm, 엽폭 31.3cm, 엽수 12.7개/주로 다른 처리구에 비해 좋은 생육상태를 보였다. 이랑폭별 수확량은 180cm에서 1,073.7kg/10a로 120cm 955.7kg/10a, 90cm 923.3/kg/10a 비해 높은 수량성을 보였다. 생리장해는 2020년 3월 저온으로 인한 냉해를 출현 초기에 모든 처리구에서 받았다. 곤달비 노지재배 발생하는 병해충은 나비·나방류, 노린재류 3종류이며 그 중 점무늬병은 모든 처리구에서 30% 이상 피해가 나타났다.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.25-32
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• 1985

Low-temperature in-bin paddy drying has been examined to study the limitations of this drying method under Korean weather conditions, the initial moisture content of the paddy, the bulk depth and the airflow rate. The results are reported and discussed with regard to drying time, energy requirements and costs, uniformity in the moisture content of the dried kernels and, finally, the quality of the paddy. The tests carried out during the paddy-drying period in 1981 and 1982 have shown that under Korean weather conditions paddy can be dried to safe storage conditions by continuous aeration with ambient air. Depending upon the initial moisture content of the kernels(19.2%-25.5% w.b.), the bulk depth(1.1-3.5m) and the airflow $(3.0-6.9m^3\;air/m^3\;paddy/min)$ the paddy could be dried within 5 to 17 days. The energy requirements and energy costs are shown to be considerably lower than for conventional high-temperature drying. No significant changes in the quality in terms of milling yield, cracking ratio, acid value and germination were observed.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.434-441
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• 1996

This study was conducted to clarify the degradation pattern, safety evaluation and penetration ratio of benomyl and bitertanol to apple used as postharvest fungicides during CA(controlled atmosphere) and cold storage. In CA storage, the degradation of benomyl and bitertanol in stored apple was slow at the early stage, while that in cold storage was, on the contrary, faster at the early stage. The initial concentrations of benomyl and bitertanol in apples applied at the standard application concentrations were 2.24 and 1.54mg/kg, respectively, and their residual amounts were below the maximum residue limits, 1mg/kg at 135 and 96 days in CA storage, 115 and 70 days in cold storage, respectively. The half-lives of benomyl and bitertanol in stored apples were 124 and 130 days in CA storage, 101 and 111 days in the cold storage, respectively, indicating that the degradation was faster in cold storage than in CA storage. The residual amount of benomyl and bitertanol in stored apples was retained more in peels than in pulps of apples.

• Applied Biological Chemistry
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• v.11
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• pp.185-188
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• 1969

This experiment was carried out to investigate on the growth, yield behavior of phosphorus at different stage of growth under the different cultivating conditions in rice plants. The results obtained were as follows; 1) The phosphorous contents was increased in the direct-sowing plots of the rooting time and the early stage of tillering, while in the middle and the later stage of growth, the transplanting plots was increased. 2) In the moisture contents, the direct-sowing plots was more increased than the transplanting plot in the rooting time and the early stage of tillering, while in the later stage of growth, the transplanting plots was increased. 3) The plant height and the weight of dry matter were also increased in the direct-sowing plots of the early stage of tillering, on the other hand, after that the transplanting plots was increased. 4) In the yield of grain, the transplanting plots was increased about 15% compared with the direct-sowing plots.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.448-454
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• 2021

This study was conducted to the effect of low air temperature and light intensity conditions on yield and quality of tomato at the early stage of growth in Korea. Inplastic greenhouses, low temperature and low temperature with shade treatments were performed from 17 to 42 days after plant. Tomato growing degree days were decreased 5.5% due to cold treatment during the treatment period. Light intensity decreased 74.7% of growing degree days due to shade. After commencing treatments, the plant growth decreased by low temperature and low radiation except for height. Analysis of the yield showed that the first harvest date was the same, but the yield of the control was 3.3 times higher than low temperature with shade treatment. The cumulative yields at 87 days after transplanting were 1734, 1131, and 854 g per plant for control, low temperature, and low temperature with shade, respectively. The sugar and acidity of tomatoes did not differ between treatment and harvesting season. To investigate the photosynthetic characteristics according to the treatment, the carbon dioxide reaction curve was analyzed using the biochemical model of the photosynthetic rate. The results showed that the maximum photosynthetic rate, J (electric transportation rate), TPU (triose phosphate utilization), and R_d (dark respiration rate) did not show any difference with temperature, but were reduced by shading. Vcmax (maximum carboxylation rate) was decreased depending on the low temperature and the shade. Results indicated that low temperature and light intensity at the early growth stage can be inhibited the growth in the early stage but this phenomenon might be recovered afterward. The yield was reduced by low temperature and low intensity and there was no difference in quality.

• Research in Plant Disease
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• v.16 no.1
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• pp.66-73
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• 2010

Field trials were conducted in Suwon, Andong, Bongwha and Taean to evaluate an anthracnose forecaster in the integrated pest management system (IPM) including anthracnose, Phytophthora blight and tobacco budworm for hot pepper in 2008-2009. Percentage of diseased fruits by pepper anthracnose and yield were compared among three treatments, no-fungicide, forecaster and conventional. The incidence and yield of the forecaster at Bongwha on two varieties were 3.1-3.5% and 30-33 kg/40 plants. These were little less than those of the conventional's 0.3-0.8% and 35-36 kg/40 plants and much higher than those of the no-fungicide's 23-27% and 18-24 kg/40 plants. The number of spray at the forecaster was 5 times, whereas those at the conventional was 11-19 times depending on the farmers. In addition, the results of an anthracnose forecaster at the other three field trials allowed in protecting hot pepper from anthracnose while reducing the amount of pesticides used and the total cost of the pathogen control. However, it is needed to improve for anthracnose forecaster when anthracnose pressure was high such as Taean where 60-80% of the incidence. Because the control values of the forecaster at Taean were between those of no-pesticide and conventional treatment at best. If anthracnose is severe early in the season, additional preventive control should be considered when the fruits were fully grown yet.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.166-172
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• 2019

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.