• Food Science and Preservation
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• v.24 no.2
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• pp.181-186
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• 2017

This study was conducted to investigate the weight loss, firmness, external color and vitamin C (VC) content of tomatoes (Lycopersicon esculentum) using non-destructive method to measure identical tomato samples during 15 days storage at low temperature and high humidity. Tomatoes were harvested at the light red stage, sorted, box packed and then stored in thermo-hygrostat ($10{\pm}1^{\circ}C$, $90{\pm}10%RH$). The quality changes in weight loss, firmness and external color were measured every 3 day interval. Weight loss was increased by $1.13{\pm}0.15%$, but it may not be considered to affect quality. Surface color of fruit was changed, especially in lightness and hue angle value. The color values were analyzed by analysis of variance (ANOVA), and the results were significant (p<0.001). Firmness of fruit declined during storage, but it did not decrease in direct proportion. On the storage of day 15, firmness was decreased to 40% of initial state. At last, all the experiment data are summarized and the relationship between firmness and weight loss is analyzed to construct a linear regression mathematical model that can predict the weight loss with the firmness value measured by non-destructive method. This research result could be useful in helping tomato exporters and suppliers to get real-time quality factor by using proposed method and regression model.

• Korean Journal of Medicinal Crop Science
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• v.19 no.3
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• pp.157-161
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• 2011

Growth characteristics, root yield and ginsenoside contents of 3-year-old ginseng in greenhouse shaded by $30^{\circ}$ sloped-curtain made of aluminum were compared to traditional shade facility in order to develop cultural practice for organic ginseng. Light transmittance ratio in greenhouse with $30^{\circ}$ sloped-curtain shade was distinctly lower than that of traditional shade from sunrise to 9 a.m., while its ratio in greenhouse was higher than traditional shade since 9 a.m. due to the reflection of light. Air temperature of greenhouse was $1.3^{\circ}C$ higher than that of traditional shade on the first ten days of August due to more reflected light. Root yield of greenhouse was 44% higher than that of traditional cultivation because of the inflow of reflected light and the decrease of disease of Alternaria and Anthracnose by blocking rainfall. Dry matter partitioning ratio of rhizome and lateral root were increased in ginseng cultivated at greenhouse due to longer survival time in leaf than traditional cultivation. Total ginsenoside contents cultivated at greenhouse was decreased in the part of taproot, while it was increased in the part of lateral and fine root compare to traditional cultivation. Individual ginsenoside contents between greenhouse and traditional cultivation showed significant difference more frequent in fine root than taproot and lateral root. Total ginsenoside contents including $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, and $Rg_2$ in whole root of 3-year-old ginseng did not showed significant difference by greenhouse and traditional cultivation.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.198-206
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• 2015

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, and thinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in a blue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the rest were thinned out at the foliation stage. $NO_3$-N, $P_2O_5$, and organic matter content differed significantly between growth conditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conventional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowing density and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment was conducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seeds sown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by the number of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plot than the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Disease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiological disorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.325-330
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• 2007

Among various food base baiting materials, beer and macerated cucumber were the most effective to induce slug that is a troublesome pest on leafy vegetables, especially on lettuce. However, the baits attracted only but did not kill the pest. When the baits were combined with various insecticidal organic materials, a few combinations such as beer and cigarette mixture successfully induced and killed the slug in the field test. The most effective combination of beer 50ml and a cigarette contained in a small plastic box killed 25 slugs per night. While macerated cucumber 50ml and a cigarette mixture killed only 4.3 slugs. The bait of beer and cigarette mixture revealed 68.4% control value against slug damage when treated for 3 consecutive days in a lettuce cultivation greenhouse. The bait also effectively reduced the slug damage in a lettuce nursery showing 58.3% control value. The method seemed highly useful for the control of slug in the organic farming system in which application of pesticides are strictly prohibited.

• Food Science and Preservation
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• v.20 no.2
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• pp.151-157
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• 2013

This study was conducted to investigate the effect of mature stages on quality of Rafito tomatoes (Lycopersicon esculentum Mill.) during storage at low temperature. Tomatoes grown in greenhouse were harvested at three different mature stages (turning, pink, and red), packaged with a 30-${\mu}m$-thick polyethylene film, and then stored at 5 and $10^{\circ}C$, respectively. The changes in firmness, soluble solids content (SSC), titratable acidity (TA), colour, lycopene content, decay, and chilling injury were measured on a weekly basis. After three weeks of storage, chilling injury and decay were found to have individually occurred at 5 and $10^{\circ}C$, respectively. As there was little change in quality at $5^{\circ}C$, it was concluded that red tomatoes could maintain their good quality for two weeks. The normal postharvest ripening was inhibited in the turning and pink tomatoes during storage at $5^{\circ}C$. The turning and pink tomatoes showed improved quality after two-week storage at $10^{\circ}C$. In particular, the turning fruits showed the highest firmness throughout the storage period. Furthermore, the red colour, SSC/TA, and lycopene content of the turning fruits reached the same levels as with the red fruits after two-week storage at $10^{\circ}C$. These results suggest that red tomatoes should be stored at $5^{\circ}C$ to inhibit decay, and that the optimum temperature for early-harvested tomato (turning and pink) is $10^{\circ}C$ for the ripening process after harvest.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.380-390
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• 2005

This study was carried out for looking into the status of susceptibility of vinyl house insect pests to insecticides. The Thrips (Thrips palmi and Frankliniela occidentalis), Mites (Tetranychus urticae), Aphids (Aphis gossypii) and Whitefly (Trialeurodes vaporariorum) were captured at various areas where the host crop was being cultivated and the susceptibility level of each pest insect was investigated. The susceptibility of each pest insect varied by insect species and areas where they were caught. The tested insecticides showed good control effect to palm thrips in 2000, but in 2003 showed decrease of effect to them. Western flower thrips showed low susceptibility to neonicotinoids, imidacloprid and thiamethoxam, but high to chlorfenapyr, spinosad, emamectinbenzoate and fipronil. Antibiotic insecticides, abamectin and milbemectin, and chlorfenapyr were very effective on mite control and dicofol still had good effectiveness to it despite of long year use. No aphid species showed resistance to pyrethroid and carbamate insecticides. Relatively new insecticides such as imidacloprid, spinosad, pymetrozine were effective to whitefly, but not were organophosphates, carbamates and pyrethroids.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.306-312
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• 2006

The objective of this study was to compare the reduction of residues in/on mini-tomato by washing methods and to evaluate the relation of reduction rates in different pesticides. Mini-tomato was sprayed with three commercial pesticides, oxadixyl, thiophanate-methyl and chlorothalonil, and harvested for washing test as 0, 5 and 7 days elapsed. The reduction rates of oxadixyl in/on mini-tomato were 61, 11 and 4%, those of thiophanate-methyl were 89, 89 and 79%, and in case of chlorothlaonil, reduction rates were 84, 84 and 88%, respectively When mini-tomato at 0 day and 5 days after spray was washed by 0.02% of $Sur-ten^{(R)}$ solution, its pesticide residues were reduced by 81 and 55% on oxadixyl, 95 and 91% on thiophanate-methyl, and 97 and 98% on chlorothlaonil. When three wettable powdered pesticides with the same recipe were sprayed, their reduction rates in/on mini-tomato by washing with water at 0, 5 and 7 days were 76, 66 and 43% on oxadixyl, 91, 83 and 82% on thiophanate-methyl, and 65, 68 and 82% on chlorothlaonil, suggesting that the washing effect may be dependent on the amounts of active ingredients and inert types of the pesticides used.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.140-144
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• 2001

Field investigations were initiated to determine possible new 'ssam' vegetable that could be grown during the summer season in highland. Korean 'ssam' means cooked rice in vegetables. The 'ssam' vegetable is called that those leaves has been used for wrapping at meal. Seventeen leafy vegetables were studied, including chard (Beta vulgaris L. var. flavescens DC.), leaf broccoli (Brassica oleracea L. var. italica), Chinese leek (Allium tuberosum Rottl.), Japanese hornwort (Cryptotaenia japonica Hassk), red leaf mustard (Brassica juncea L.), green leaf mustard (Brassica juncea L.), leaf parsley (Petroselinum crispum Nijim), pakchoi (Brassica campestris L. ssp. chinensis Jusl.) tatsoi (Brassica campestris var. narisoma), kale (Brassica oleracea var. acephala), collard (Brassica oleracea var. acephala), Korean mint (Agastache rugosa O. Kuntze), romaine lettuce (Lactuca sativa L. var. longifolia Lam.), red leaf chicory (Cichorium intybus L. var. folisum), red chicory (Cichorium intybus L. var. folisum), green leaf chicory (Cichorium intybus L. var. folisum), and sprouting broccoli (Brassica oleracea L. var. italica). Date of the first harvest in 1999 was July 10th in chard, leaf broccoli, red mustard, mustard, leaf parsley, pakchoi, tatsoi, kale, collard, Korean mint, red leaf chicory, red chicory, green leaf chicory, and sprouting broccoli. Date of the first harvest for Chinese leek, Japanese hornwort, and romaine lettuce was from the middle of June to the late of August. Based on ratings on marketable yield, we found good leaf shape, taste and yield in chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory. Even though the most of all these vegetables were obtained high scores by test panels in shape, taste and quality, but some of them revealed inadequate leaf size as a 'ssam' vegetable. That problem will be solved by control of harvesting time. On the basis of this observation, chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory were rated as promising 'ssam' vegetable by analysis of profits, adaptation, and quality.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.180-183
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• 2011

'Yeomyeong', a new welsh onion (Allium fistulosum L.) variety, is developed by the Bioenergy Crop Research Center, NICS, RDA in 2004. This variety, as interspecific $F_1$ hybrid, is developed by a cross between onion (Allium. cepa L.) and welsh onion (A. fistulosum L). The first cross was conducted in 2003 between MOS8, onion male sterile line and G2, welsh onion inbred line. Horticultural and yield characteristics of this hybrid $F_1$ line was investigated in greenhouse for 2 years from 2004 to 2005 with fall cropping cultivation. It has a single pseudostem plant type, anthocyanin-colored pseudostem, and male sterile umbel. It showed intermediate plant type of the maternal parents in overall plant characteristics. 'Yeomyeong' is fall sawing variety and has higher plant height and pseudostem length than that of check variety 'Gumjang'. The yield potential of this variety was about 130.1MT/ha in greenhouse in spring harvseting season. This variety would be adaptable to the fall sowing cultivation in green house.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.173-181
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• 2022

This study was carried out to investigate the residual characteristics of flubendiamide in kale to establish pre-harvest residue limits (PHRL) and the removal efficiency according to the washing solvent and method. Field tests were conducted at two different greenhouses, field 1 (Anseong-si, Gyeonggi-do) and field 2 (Incheon-si, Gyeonggi-do). According to the safe use guidelines kale was sprayed with flubendiamide twice every 10 days and harvested 0 (after 2 h), 1, 2, 3, 5, 7 and 10 days after the final application. The biological half-live of flubendiamide in kale was calculated based on dissipation curves of the pesticide in samples analyzed by liquid chromatography coupled with tandem mass spectrometry. In the analysis, method limits of quantitation (MLOQ) were 0.01 mg/kg, and recoveries performed with two different fortification levels of 10 MLOQ and maximum residue limit (0.7 mg/kg) were 104.2±3.6 and 101.9±10.2%, respectively. The dissipation rate constant of flubendiamide in kales were 0.2437 at field 1 and 0.1981 at field 2. PHRL calculation equations obtained using the dissipation constants estimated as follows: if the residual concentration of flubendiamide in kale on 10 days before harvest is less than 8.0 mg/kg, the residual concentration on the harvest would be under MRL. The removal of flubendiamide from kale was the greatest when it was washed with vinegar (39.8%), followed by baking soda (31.7%), calcium powder (30.2%), neutral detergent (27.2%), and tap water (15.9%). The results of this study would be useful for both farmers and consumers to produce or consume safe agricultural products.