• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.130-140
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• 2014

Recently, some of the previous studies reported that tolclofos-methyl is still exist in ginseng cultivated soil, even though it is has been banned for ginseng. Therefore, the current study was aimed to examine the levels of absorption and translocation of tolclofos-methyl from ginseng cultivated soil to ginseng root and leaf stem for the period of 1 year. For this study, ginseng plants were transplanted in pots and treated with $5.0mg\;kg^{-1}$ of tolclofos-methyl (50% WP). At the end of each interval periods (every three months) the samples (soil, roots and leaf stems) were collected and analyzed the absorption and translocation levels of tolclofos-methyl using gas chromatography and mass spectrometry (GC-MS). The limit of quantitation of tolclofos-methyl was found to be $0.02mg\;kg^{-1}$ and 70.0~120.0% recovery was obtained with coefficient of variation of less than 10% regardless of sample types. In this study, a considerable amount of translocation of tolclofos-methyl residues were found in soil (4.28 to $0.06mg\;kg^{-1}$), root (7.09 to $1.54mg\;kg^{-1}$) and leaf stem (0.79 to $0.69mg\;kg^{-1}$). The results show that the tolclofos-methyl was absorbted and translocated from ginseng cultivated soil to ginseng root and ginseng leaf stem and found to be decreased time-coursely. Secondly, we were also analyzed soil, root and leaf stems samples from Hongcheon, Cheorwon, Punggi and Geumsan by GC-MS/MS (172 pesticides), LC-MS/MS (74 pesticides). In this study, 43 different pesticides were detected ($0.01{\sim}7.56mg\;kg^{-1}$) in soil, root and leaf stem. Further, tolclofos-methyl was detected 4 times separately in root sample alone which is less ($0.01{\sim}0.05mg\;kg^{-1}$) than their maximum residual limit (MRL) in ginseng. Consequently, the results from both studies indicate the residues of tolclofos-methyl found in ginseng cultivated soil and ginseng ensuring their safety level. Moreover, long-term evaluations are needed in order to protect the soil as well as ginseng free from tolclofos-methyl residues.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.1-9
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• 2006

Regardless of the recent observed warmer winters in Korea, more freeze injuries and associated economic losses are reported in fruit industry than ever before. Existing freeze-frost forecasting systems employ only daily minimum temperature for judging the potential damage on dormant flowering buds but cannot accommodate potential biological responses such as short-term acclimation of plants to severe weather episodes as well as annual variation in climate. We introduce 'dormancy depth', in addition to daily minimum temperature, as a complementary criterion for judging the potential damage of freezing temperatures on dormant flowering buds of grape vines. Dormancy depth can be estimated by a phonology model driven by daily maximum and minimum temperature and is expected to make a reasonable proxy for physiological tolerance of buds to low temperature. Dormancy depth at a selected site was estimated for a climatological normal year by this model, and we found a close similarity in time course change pattern between the estimated dormancy depth and the known cold tolerance of fruit trees. Inter-annual and spatial variation in dormancy depth were identified by this method, showing the feasibility of using dormancy depth as a proxy indicator for tolerance to low temperature during the winter season. The model was applied to 10 vineyards which were recently damaged by a cold spell, and a temperature-dormancy depth-freeze injury relationship was formulated into an exponential-saturation model which can be used for judging freeze risk under a given set of temperature and dormancy depth. Based on this model and the expected lowest temperature with a 10-year recurrence interval, a freeze risk probability map was produced for Hwaseong County, Korea. The results seemed to explain why the vineyards in the warmer part of Hwaseong County have been hit by more freeBe damage than those in the cooler part of the county. A dormancy depth-minimum temperature dual engine freeze warning system was designed for vineyards in major production counties in Korea by combining the site-specific dormancy depth and minimum temperature forecasts with the freeze risk model. In this system, daily accumulation of thermal time since last fall leads to the dormancy state (depth) for today. The regional minimum temperature forecast for tomorrow by the Korea Meteorological Administration is converted to the site specific forecast at a 30m resolution. These data are input to the freeze risk model and the percent damage probability is calculated for each grid cell and mapped for the entire county. Similar approaches may be used to develop freeze warning systems for other deciduous fruit trees.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.347-366
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• 2023

In the present study, the vegetation was classified using the phytosociological method and canonical-correlation analysis (CCA) was implemented to analyze correlation between community structure and environmental factors in the natural habitats of forest byproducts, especially medicinal plants, such as Cudrania tricuspidata, Sorbus commixta, and Hovenia dulcis, in 2021-2022 to provide primary ecological data to establish environmental conditions for wild vegetable cultivation. A total of 11 plots in five regions, 8 plots in three regions, and 17 plots in 5 regions were selected for the natural habitats of C. tricuspidata in southern Korea, S. commixta in high mountains, and H. dulcis in valleys of central Korea, respectively. The importance value in each community was respectively analyzed as follows, in C. tricuspidata community, the importance value of C. tricuspidata (61.10) was the highest, followed by Celtis sinensis, Pinus thunbergii, Neolitsea aciculata, Styrax japonica, Carpinus coreana, Quercus serrata, and Q. acutissima. In Sorbus commixta community, Q. mongolica (57.21) was the highest, followed by, S. commixta (42.58), Betula ermani, Tilia amurensis, A. pseudosieboldianum, A. tschonoskii var. rubripes, Cornus controversa, Magnolia sieboldii, and Taxus cuspidata. In H. dulcis community, H. dulcis (64.58) was the highest, followed by Zelkova serrata, Cornus controversa, A. mono, Q. serrata, C. cordata, and Juglans mandshurica. As the result of the analysis on DBH of the major species having the high importance value, in C. tricuspidata community, C. tricuspidata, C. sinensis, Neolitsea aciculata, and C. coreana show the density of normal distribution, so the dominant status of these species is likely to continue. In S. commixta community, S. commixta show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and Q. mongolica, B. ermani and T. amurensis, show the density of normal distribution, so the dominant status of these species is likely to continue. In H. dulcis community, C. cordata, and J. mandshurica show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and H. dulcis, Z. serrata, C. controversa and A. mono had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. The results of CCA ordination analysis using 11 environmental factors and 30 communities of three taxa classified by TWINSPAN analysis revealed that the altitude showed the strongest correlation with the vegetation. C. tricuspidata community was distributed on the moderate and gentle northeastern slope at low altitude with the highest pH, C.E.C, Ca²⁺, and Mg² and various P₂O₅, whereas S. commixta community was distributed on the steep slope at high altitude with the highest O.M and T-N and lower P₂O₅, Ca²⁺, Mg²⁺, C.E.C and pH, which is the opposite tendency of the environment of C. tricuspidata community. H. dulcis community was distributed on the gentle northern slope at lower altitude with an average pH, O.M, T-N, Ca²⁺, Mg²⁺, and C.E.C, except higher P₂O₅.