• Research in Plant Disease
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• v.21 no.2
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• pp.89-93
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• 2015

This study was carried out to develop the economic thresholds for the control of bacterial spot of red pepper. The correlation between diseased leaf rate and yield in field was Y=-0.724X+281.58, $R^2=0.78$, $r=-0.88^{**}$. The correlation between diseased leaf rate and yield loss in field was Y=0.813X+15.95, $R^2=0.78$, $r=0.88^*$.We found that control thresholds was below 30.3% diseased leaves rate per plant in field. The economic control thresholds for bacterial spot of red pepper was below 16.3%.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.149-154
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• 2008

Pyrausta panopealis is the major pest in green perilla. The larva weaves a web on the shoot of green perilla and damages. In case of extreme, The larva cuts the main branch of green perilla and the leaf of green perilla isn't harvested anymore. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for P. panopealis injuring green perilla in green-houses. Different densities of P. panopealis ranged from 1 to 20 crops (2 units per crop) per 100 crops on 13. June, early inoculation. The number of injured leaf and the rate of injured crop were increased by 23. June, on the other hand were decreased after that day. Also, the amount of yield sow the same result above. The economic loss time calculated by the ratio of cost managing this moth to market price (C/V) (C: cost managing a moth, V: Market price) was 4.0%. The economic injury level was 5.1 larval per 100 crops. The control thresholds calculated by 80% level of economic injury level was 4.1 larval per 100 crops.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.317-325
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• 2006

According to the preceding survey on insect pests of the green perilla, Perilla frutescens var. japonica HARA, The major pests were Aphis egomae Shinji, Pyrausta panopealis (Walker), Tetranychus urticae Koch, Polyphagotarsonemus lotus Banks, Tetranychus kanzawai Kishida at Guemsan, Chungnam, 2004. Aphis egomae causes nearly 100% injury of the green perilla in uncontrolled green houses. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for A. egomae injuring green perilla in green houses. Different densities of A. egomae ranged from 1 to 80 aphids per 100 plants in early inoculation. The mean injurying rate of plant was 2.4% to 40.5% at the end of June at differently inoculated levels. The economic loss time calculated by the ratio of cost managing aphid to market price (C/V) (C: cost managing aphid, V: Market price) in early season (from May to 13. June) was 5.8% and in peak season (from 13. June to 30. June) was 9.3%. Economic injury level in early and peak season was 5.3 aphids per plant and economic injury levels in peak season were 0.6 aphids per plant and 7.6% injured rate of plant. The control thresholds calculated by 80% level of economic injury level in peak season were 0.5aphids per plant and 6.1% injury rate of plant, respectively.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.409-414
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• 2007

Economic injury levels and economic thresholds were estimated for the american serpentine leafminer (Liriomyza trifolii) on greenhouse eggplant. Liriomyza trifolii density was increased until the late June and decreased after the July in innoculation on may 17. Growth of an aerial plants and fruits were not different in treatment respectively. But total number of fruits and yields were decreased on higher inoculation density. Whereas the rate of yield loss was increased. The rates of damaged leaf by L. trifolii were increased on higher inoculation density and the peak was 65%. The number of commodity fruits and the rates of commodity fruit were become lower than non-treatment (72.2%). The rates of damaged leaf area were 5.3, 11.7, 19.7, 25.7% on inoculation densities and the rates of yield loss were 0.6, 4.8, 9.8, 14.7%, respectively. There existed close correlation between rate of yield loss and inoculation density (Y = 0.76779X + 0.298354, $R^2\;=\;0.9599$). Considerated of the results, the economic injury levels of L. trifolii on eggplant greenhouse was 6.1 adults per 4 plant and the economic thresholds was 4.9 adults per 4 plant.

• Research in Plant Disease
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• v.16 no.3
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• pp.285-289
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• 2010

The experiments were carried out in fields for two years from 2008 to assess yield losses of squash due to powdery mildew caused by Sphaerotheca fuliginea and to determine its economic thresholds. Powdery mildew disease was first observed in late June, about 50 days after field-transplanting, progressed rapidly during late July to early August, and began to reduce from late August. Powdery mildew severity was negatively correlated with squash yields. A positive correlation was observed between fruit weight and % marketable fruits. A simple linear regression model was obtained as Y=-10.399 X + 6607.5 with $R^2$ = 0.9700 when squash yields (Y) was predicted using powdery mildew severity as an independent variable(X). Spray threshold for maximizing squash yields without economic considerations was estimated as 6.5% in terms of leaf lesion area with powdery mildew. Economic threshold and economic spray threshold able to compensate the costs of fungicide sprays were determined as 21.6% and 17.3% in leaf lesion area, respectively.

• KDI Journal of Economic Policy
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• v.42 no.1
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• pp.31-56
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• 2020

Does financial development contribute to economic growth? The literature finds that an expansion in financial resources is useful for economic growth if the degree of financial development is under a certain threshold; otherwise, the expansion is detrimental to growth. Almost every published study, however, considers country-panel data. Accordingly, the results are not directly applicable to the Korean economy. By examining Korean time-series data, this paper finds that there is an inverse U-shaped relationship between the per capita real GDP growth rate and private credit (as a percentage of nominal GDP)-a well-known measure of quantitative financial development, where the threshold is 171.5%. This paper also finds that private credit is positively associated with economic growth if the share of household credit out of private credit is less than 46.9%; otherwise, private credit is negatively associated with economic growth. As of 2016, the ratio of private credit to GDP and the ratio of household credit to private credit are both higher than the corresponding thresholds, which implies that policymakers should place more emphasis on qualitative financial development than on a quantitative expansion of financial resources.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.113-118
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• 2015

This study was carried out to develop the economic thresholds for powdery mildew on pepper. To investigate the relationship between powdery mildew incidence degree and yield, experimental plots with ten treatments as initial disease degree were established. Disease intensity exhibited negative and significant correlation with fruit characters like fruit length, fruit diameter, fruit weight. The adverse effect of the disease on these characteristics was low yield, exhibiting significant negative correlation with disease intensity. There existed close correlation between rate of infected leaf area and yields in the plastic house (Chonhatongil: Y = -3.44X+291.09 $R^2=0.73$, Buchon: Y = -2.14X+327.9 $R^2=0.78$). There existed close correlation between rate of infected leaf area and yield loss in the plastic house (Chonhatongil: Y = 2.14X+15.45 $R^2=0.76$ $r=0.87^{**}$, Buchon: Y = 3.44X+114.21 $R^2=0.73$ $r=0.85^{**}$). Control thresholds diseased rate on powdery mildew of pepper was below 3.2 to 7.3% rate of infected leaf area per plant in the plastic house. The economic thresholds for powdery mildew of pepper was below 3.8 to 6.2% rate of infected leaf area per plant in the plastic house.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.81-86
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• 2009

Economic injury level and control thresholds for the management of beet army worm, Spodoptera exigua (Lepidoptera: Noctuidae) were evaluated on chinese cabbage of two different planting time. Two inoculation times were tested for each planting and the number of inoculated larva was 10, 20, 40, 80, respectively. Damages of leaves by first inoculation were 63.2% after eight days planting on 80 larva inoculation plot. By the second inoculation, those were below 50% after 20 days planting on the end of September. The linear relationships between population density and yield reduction were as following; Y = -10.62x + 867.9 ($R^2\;=\;0.643$) for 5 days and Y=-6.432x + 1074 ($R^2\;=\;0.720$) for 20 days. Based on these results the economic injury level was 5.4 larva for five days and 9.0 larva for 20 days per 20 chinese cabbage. The control thresholds calculated by 80% level of economic injury level were 4.3 and 7.2 larva, respectively.

• East Asian Economic Review
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• v.16 no.4
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• pp.363-394
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• 2012

WTO Government Procurement Agreement (GPA) was designed to liberalize and expand trade in government procurement. Revised GPA was implemented in 1996 and the latest revision was completed (but not yet implemented) in 2012, but as a plurilateral agreement. Since the end of the UR, there has been attempts by various WTO members to liberalize trade in the government procurement market - through an expansion of Parties who are signatories to GPA, and through a negotiated agreement on transparency in government procurement. The attempt to expand the Parties who are signatories to the GPA - attempt to increase the width of the coverage of the agreement - has been somewhat successful, but I argue that the goal should be to further liberate the government procurement markets of the current Party members - to reduce thresholds and other barriers which limit market access even to other GPA members, in other words, to increase the depth of coverage. Taking cue from Korea's FTA, I propose a two-level liberalization of the government procurement market under the GPA: A "light" level which would be the same as the current level of liberalization; and a "deep" level with lower thresholds and less exemptions. I argue that, as seen in Korea, with FTAs, many GPA Parties already have multiple levels of liberalization (i.e, spaghetti-bowl effect of FTAs), but by limiting the levels of liberalization to two, we can seek the best of deep liberalization but reduce the spaghetti-bowl effect.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.71-77
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• 2011

This study was conducted to predict the yield loss of red pepper and to determine the economic weed thresholds levels for red pepper cultivation field from competition with the most serious weeds, Echinochlor crus-galli (L.) P. beauv. (barnyard grass) and Chenopodium album L. (goosefoot) in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=317.0 kg/ (1+0.1707x), $R^2$=0.895 in E. crus-galli and y=323.2 kg/(1+0.2900x), $R^2$=0.896 in C. album L.. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 6.5 plant $100m^{-2}$ in E. crus-galli, and 3.7 plant $100m^{-2}$ in C. album L..