• Weed & Turfgrass Science
• /
• v.6 no.4
• /
• pp.350-354
• /
• 2017

Conyza canadensis is the weed species which most frequently develops resistance to glyphosate in many agricultural crop fields. The continuous use of glyphosate has resulted in the spontaneous occurrences of resistant biotypes. This research was conducted to investigate the response of suspected C. canadensis biotypes to glyphosate. Seeds of C. canadensis were collected from 18 sites in tangerine orchards in Jeju province of Korea. In the preliminary screening, 6 resistant and 12 susceptible biotypes were found at the recommended glyphosate rate ($3.28kga.i.ha^{-1}$). The susceptible biotypes were completely killed at the field application rate whereas the resistant biotypes were initially injured but recovered 14 days after glyphosate application. This is the first case of glyphosate resistance found in Korea despite the national ban on genetically modified glyphosate tolerant crops cultivation. Extended monitoring should be conducted to understand how widely spread the glyphosate resistant C. canadensis is and to estimate the severity of this weed problem in the tangerine orchards of Korea.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.7
• /
• pp.214-221
• /
• 2018

The purpose of this study is to analyze the shipbuilding structure of field tangerine by ten days and by month. By estimating and analyzing the price flexibility function of field tangerines, this study determines whether the shipment control can stabilize and increase the income of field tangerine farmers and provides policy implication. Considering the overall market, a 1% increase in shipment volume indicates that the coefficient of price flexibility varies with ten days and month. The greatest decline is from late October to early January. Therefore, a greater necessity of shipment control is required during late October and early January. The coefficient of the dummy variable (DUM_Q) indicates the year in which the quality declines is statistically significant and sign. The coefficient of the dummy variable (DUM02) represents the year in which more than 7 days after the New Year holidays are in February is statistically significant and sign from early October to late January. Therefore, it can be seen that the necessity of shipment control is more required when New Year holidays are in February. The greatest decline in the coefficient of price flexibility is from October to December. Therefore, a greater necessity of shipment control is required during October and December. The signs of coefficients of DUM01 and DUM_Q dummy variable of the price flexibility function suggest that the need for shipment control is more important when quality is worse than better quality and that the necessity of shipment control is more required when New Year holidays are in February, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.303-311
• /
• 2020

The acreage of tangerines in the U.S. sharply rose from 19,000 ha in 2009 to 27,000 ha in 2016, an increase of 42% in 7 years. Considering the recent surge in tangerine exports to Japan, the export volume of 6-7 thousand tons is highly likely to increase in the future. Therefore, the purpose of this study was to analyze the economic impact of U.S. tangerine imports on the Korean citrus industry under various scenarios. In order to examine the possibility of imports of U.S. tangerines, the unit price of U.S. exports to Japan was used since U.S. tangerines are not imported to South Korea. Citrus fruits are divided into field citrus, house citrus, and late-maturing citrus (including winter season citrus) based on the cultivation method and variety used to analyze. Considering both the field and house seasons, the import volume of U.S. tangerines can be expected to rise from roughly 4,700 tons in 2021 to 10,000 tons in 2027. Imports of U.S. tangerines may be pushed up or delayed depending not only on the harvest method and quality of domestic field and house citrus but also on the harvest of U.S. tangerines. However, it is necessary to note that tangerines could be imported after 2021, when the tariff rate on U.S. tangerines will fall below 50%.

• Journal of Convergence for Information Technology
• /
• v.11 no.11
• /
• pp.288-295
• /
• 2021

This study was conducted to investigate the effect of end paper adsorbed with mask pack active ingredients on hair during permanent wave treatment. Permanent wave was performed with purchasing mask packs containing green tangerine, collagen, and Houttuynia cordate active ingredients among commercially available mask packs and adsorbing them to the end paper. As experimental methods, hair thickness, hair moisturizing power, tensile strength, hair epidermis observation using SEM, and hair constituent element analysis using EDS were performed. As a result of the experiment, it was confirmed that the experimental group treated with Houttuynia cordate active ingredient on the end paper had a hair protection effect as a result of hair thickness, tensile strength, hair epidermis observation, and hair component analysis. In addition, it was confirmed that the experimental group treated with green tangerine active ingredient on the end paper contained a relatively large amount of moisture in the hair moisturizing power test result. It is hoped that the development and research of various materials and tools will proceed so that basic cosmetic products containing active ingredients can be developed and used as hair cosmetics, and applied during chemical treatment in the industrial field.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.108-114
• /
• 2021

Green colored citrus is the immature fruit of the field citrus crop in Jeju, and its demand has been growing recently as it is known to contain a large amount of carotinoid, pectin, and vitamin C. It differs from the traditional varieties of blue tangerine, which are green in February and turn in yellow in March-April. This study analyzed the effects of the increased demand in green citrus on the field citrus industry. For our analysis, a partial equilibrium supply-demand model was established with a dynamic recursive structure using data from 1989-2017. Model calibration was also conducted to determine the best supply-demand model and then, the impacts of increasing demand for green immature citrus in Jeju for 2018-2030 was simulated. The simulation results show that there is no significant impact on the producing area prior to 2022, but there is a distinguishable increase of 18ha in 2023, 52ha in 2025, and 142ha in 2030. It was also predicted that revenue would increase by KRW 7.75 billion on average from 2021-2030.