• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.359-367
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• 2023

Grapes are one of the most important fruit trees both domestically and globally. Recently, changes in plant phenology and frequent low temperatures due to climate change are increasing the possibility of damage to grape shoots in spring, which is a serious threat to grape production. This study was conducted to investigated the severity of shoots damage and the change of free sugar content in the plant organs by phenological stage, especially, from germination to leafing period. Furthermore, in order to compare the cold hardiness among grape varieties including 'Campbell Early', 'Kyoho' and 'Shine Muscat' widely grown in Korea, lethal temperature (LT₅₀) and free sugar content by grape variety were analyzed. Shoot damage by low temperatures continued to increase as the phenological stage progressed gradually, from the bud burst to the fourth leafing stage. On the other hand, the free sugar content of each organ except leaves continued to decrease, showing pattern to similar to cold hardiness. This indicates a close relationship between free sugar content and cold hardiness. In terms of cold hardiness comparison among grape varieties, 'Shine Muscat' showed the highest cold resistance in the leafing stage with the lowest LT₅₀ and the highest total free sugar content. Next was 'Kyoho' and 'Campbell Early'. There are clear differences in cold hardiness depending on the variety. However, it is not the same at all growth stage. It may change according to phenological stage and influenced by free sugar content at that time.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.339-346
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• 2018

This study was conducted to monitor the current status of pesticide residues in a total of 297 agricultural products for raw juice from January 2017 to September 2017. Pesticide residues in samples were analyzed by multiresidue method for the determination of multiclass pesticide with an aim to detect 220 pesticides using GC/ECD, GC/NPD, TOF/MS, LC/PDA, LC/FLD, and LC/MS-MS. The analysis revealed the presence of nine pesticides in 14 samples. The detected pesticides were chlorpyrifos, cyflufenamid, chlorothalonil, pendimethalin, azoxystrobin, pyridalyl, imazalil, fludioxonil and procymidone. The kinds of detected crops were mandarin, carrot, apple, celery, chicory, orange and grape. Risk assessment evaluated human health exposure with the ratio of EDI (Estimated daily intake) to ADI (Acceptable daily intake) of pesticides detected and the range of %ADI (the ratio of EDI to ADI) values was 0.0011~6.7087% and safety level.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.391-402
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• 2013

Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.295-303
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• 2021

We analyzed berry skin coloration, anthocyanin accumulation, and plant hormone contents in berry skins to determine the effect of night temperature at veraison on berry skin coloration in 'Kyoho' grapevines (Vitis labruscana L.). Vines were grown under 21, 24, and 27℃ at night for 20 days at veraison, from 40 to 60 days after full bloom (DAFB). Berry skin coloration of 'Kyoho' grapes was more suppressed in 27℃ treated vines, followed by that in 24℃ treated vines, than that in 21℃ treated vines. Cluster and berry weight and soluble solids content was lower in 24 and 27℃ treated vines than in 21℃ treated vines. Anthocyanin started to accumulate from 60 DAFB in berry skin of 21℃ treated vines, and malvidin and total anthocyanin content increased until 100 DAFB. The total and most of the individual anthocyanins decreased in 24 and 27℃ treated vines; however, peonidin did not decrease in 24℃ treated vines compared to that in 21℃ treated vines. Abscisic acid (ABA) peaked at veraison in berry skins of 21℃ treated vines and decreased thereafter until 100 DAFB. The increase in ABA content was inhibited in berry skins of 24 and 27℃ treated vines. Gibberellin (GA) content in berry skins decreased rapidly at veraison, with the decrease being slower under 27℃ than under 21℃. ABA/GA in berry skins of 21℃ treated vines peaked at 60 DAFB and decreased thereafter until 100 DAFB. However, ABA/GA decreased in berry skins of 24 and 27℃ treated vines, with reduced anthocyanin accumulation. Therefore, high night temperature (above 24℃) at veraison suppressed the berry skin coloration of 'Kyoho' grapes with changes in anthocyanin contents and composition due to the decrease in ABA/GA ratio and fruit soluble solids contents.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.234-242
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• 2019

We analyzed the anthocyanin accumulation, abscisic acid (ABA), gibberellic acid (GA) contents and metabolic genes expression in berry skins under high temperature (High T) at veraison, in order to investigate the cause of bad coloration of 'Kyoho' grape due to High T in summer season. The coloration of 'Kyoho' grapes was stopped by High T for 10 days from veraison, and the fruit quality was not affected except skin color. Total anthocyanin of skins was decreased by High T treatment and malvidin and peonidin were decreased compared to control. In berry skins, ABA content did not decrease by High T treatment, but it was rather higher than that of control. GA content was increased about two times compared to the control after 10 days of High T treatment, which caused decreased ratio of ABA/GA. Analysis of expression of anthocyanin biosynthetic genes showed that the early biosynthetic genes were not affected by High T and the expression of UFGT was decreased by temperature treatment. ABA biosynthetic gene expressions were not affected by High T and the expression of GA20ox1 and GA2ox1/2, which are known to regulate the biosynthesis and inactivation of GA, were increased and decreased by High T, respectively. Therefore, the bad coloration of 'Kyoho' grapes under the High T at veraison was due to inhibition of anthocyanin biosynthesis of skin, and it was suggested that the anthocyanin biosynthesis was controlled by the ratio of ABA and GA rather than ABA content.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.233-246
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• 2012

In this study, we investigated the applicability of the photostimulated luminescence(PSL), thermoluminescence(TL) and electron spin resonance(ESR) methods for various foods which are not allowed to be irradiated in Korea. All 15 foods including sesame, almond, peanut, cocoa powder etc. were analyzed. Samples were irradiated at 1~10 kGy using a $^{60}Co$ gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative(lower than 700). The photon counts irradiated(1 kGy) dried shrimp, roasted peanut and seasoned peanut showed positive(higher than 5,000) and the other samples were negative or intermediate(> 700 and < 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal(single-line) intensity of irradiated foods was higher than non-irradiated foods. In particular, the specific ESR signals of irradiation-induced crystalline sugar, cellulose and bone radical were detected in dried plum, raisin, dried cherry, mango(dried, frozen), rambutan, cocoa(powder), cinnamon, parsley, carrot, broccoli, dried arrow squid, dried pollack and dried shrimp. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods because TL method is not able to detect the irradiated foods rarely composed of minerals. ESR is also a difficult method to detect the changes of ESR signal patterns of food. It is concluded that TL analysis or ESR assay is suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.279-285
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• 2002

Pesticide residues in some fruits collected at Noeun wholesale market, Daejeon were surveyed and assessed its risk. In 120 samples, the detection rate of pesticide was 70.8% and the rate exceed MRL was 1.67%. Highly detection rate of commodities was apple, peach and grape. Organophosphorus, organochlorine and pyrethroid insecticide were found with similar rate relatively, but most of fungicides were procymidone(dicarboximides) and chlorothalonil(organochlorine). The order of detected pesticide were chlorothalonil, chlorpyrifos, fenvalerate, procymidone, deltamethrin and EPN. In order to assess risk estimated intake amount of each pesticide was compared to ADI. Although some peach were exceed MRL the total amount and uptake pesticides was less than 1.22% comparing to ADI.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.782-788
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• 2010

Detail management standard on soil conditions in 'Kyoho' grapes were not yet made. Therefore, this study was carried out to investigate the optimum soil environmental conditions on production of high fruit quality in 'Kyoho' grapes. We established using correlation between fruit quality and soil condition. These results were used to develop soil management guideline with promoting efficiency and minuteness in grape vineyard. Soil conditions were analyzed at total 80 vineyards in major grape producing areas such as Ansung, and Cheonan (40 orchards an area). The soil environmental factors affected fruit weight were soil pH of 36.6%, cultivation layer depth of 23.3%, and cation of 17.8%. The soil condition factors affected sugar content were soil hardness of 24.4%, cation of 24.1% and organic matter content of 22.1%. Cultivation layer depth, soil texture, and phosphate content were low as relative contribution. Coloring was involved with organic matter content, CEC (cation exchange capacity), and saturated hydraulic conductivity. while soil pH, cultivation layer depth, and phosphate content showed low contribution. Finally, relative contribution on fruit quality related with sugar content, fruit weight, and coloring were soil hardness of 28.0%, organic matter content of 25.0%, soil pH of 12.9%.

• Journal of The Korean Association For Science Education
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• v.35 no.4
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• pp.537-548
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• 2015

This study aims to identify and compare the patterns of scientific questions generation among elementary science-gifted and general students when conducting observational tasks. The pattern in generating scientific questions, which is distinguished from other types of scientific questions, is the manner that students generate a variety of types of questions in an inquiry process. To analyze the patterns in generating scientific questions, the task of observing dry grapes in soda pop, candlelight, and dyed celery were selected as suitable tasks. The subjects were 26 science-gifted students participating in a gifted education program and 27 general students in an elementary school in the same city. They were all sixth graders. The results of this study are as follows: First, the patterns of scientific questions generation among gifted students and general students during observational tasks were classified into five patterns: [Pattern 1] single, [Pattern 2] sequential, [Pattern 3] repetitive, [Pattern 4] circulative, [Pattern 5] repetitive, and circulative. Second, gifted students and general students presented all of the five patterns, but the frequency of the patterns indicated differences between the two groups. The gifted students primarily presented [Pattern 3] and [Pattern 5]. On the other hand, the general students mainly presented [Pattern 1], [Pattern 2], and [Pattern 3]. These results suggest that the ways of generating scientific questions are very much as important as the types of questions. Teachers can establish teaching-learning strategies for generating scientific questions appropriate to learner's characteristics.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.277-281
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• 2011

A rapid and very sensitive high-performance liquid chromatography/atmospheric-pressure chemical-ionization mass spectrometry method to detect ethylenethiourea (ETU) fungicide residues in fruits was developed. Methylene chloride was used as the surface extraction solvent for the target component. Recovery rates improved when cysteine hydrochloride and sodium carbonate were added to product prior to fortification. The limits of detection and quantification were approximately 0.006 and 0.02 mg/kg, respectively, from mandarin oranges. Recoveries from mandarin oranges, oranges, bananas, and pears, spiked in the range of 0.05-0.5 mg/kg, averaged 80-100%. The proposed method was used to monitor the presence of ETU in commercial fruits purchased from different markets in Seoul, Korea. ETU was found in four orange peels and in three mandarin orange peel samples. The highest ETU residue levels were $73.6{\mu}g/kg$ and $29.8{\mu}g/kg$.