• Research in Plant Disease
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• v.10 no.1
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• pp.25-29
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• 2004

Over 98％ of Dendranthema x grandiflorum plants growing under a glasshouse in Gumi, Korea were infested with Meloidogyne hapla. Dendranthema x grandiflorum cv, 'Ardilo' had fewer eggmass (3.3/g root), followed by cv. 'Euro' (6.5), and cv. 'Monarisa' had the most eggmasses(17). The coefficient correlation between plant growth and nematode reproduction(number of eggmass per plant) indicated that nematode reduced chlorophyll content in leaf (r = -0.418, p = 0.059; r = -0.463, p = 0.040). Number of flowers, number of leaves and stem height to flower were positively correlated with flower weight(p < 0.05).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.452-458
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• 2021

Roots are the most important organs in plants that absorb nutrients and moisture from the soil. However, owing to difficulties in root data collection, root research is still poorly conducted as compared to shoot research. Recent advancements in crop phenotyping, through advanced imagery data, are rapidly increasing, and artificial intelligence has been applied in various crop root research. Depending on the purpose, different root analysis methods have been developed that measure roots directly in soil or after separation from the soil. Each method has its advantages and disadvantages; therefore, it can be used in accordance with the research interest. Therefore, this review introduces root analysis methods that use imagery systems to help domestic researchers precisely study plant roots or root architecture.

• Transactions of Materials Processing
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• v.31 no.2
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• pp.57-63
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• 2022

The current study performed formability analysis of a heat exchanger separator for an electric vehicle to apply a high-strength aluminum sheet based on parametric analysis. Mechanical properties for sheet metal forming simulation were evaluated by tensile test, bulge test, and Nakajima test. Two-stage crash forming was established by considering the mass production process using conventional low-strength aluminum sheets. In this study, FEM for the two-stage forming process was conducted to optimize the corner radius and height for improving the formability. In addition, the possibility of a one-stage forming process application was confirmed through FEM. The prototype of the sample was manufactured as FEM results to validate the parametric analysis. Finally, this result can provide a one-stage forming process design method using the high-strength aluminum sheet for weight reduction of a heat exchanger separator for an electric vehicle.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.99-108
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• 1995

The experiment was carried out to define the effect of the boron in nutrient solution on the development of mulberry root and cold damage. The length of shoots only attained about 50cm and then stopped in case of boron deficiency, while the mulberry trees developed vigorous and attained over 190cm long under boron supply condition. When boron is deficient, the measles appeared on surface of the stem and the necrosis appeared on the petiole, midribs and veins of leaves. At 70 days after planting, almost all new roots and old roots changed to brown, the lateral roots became necrosis by boron deficiency. After three days of stopping boron supply, many new roots changed to brown and after two days of boron resupply, new roots began to grow out and then new roots normally developed. Content of boron in leaves and barks increased by the increase of boron concentration in nutrient solution and maximum boron content in leaves and barks was obtained with boron-sufficient treatment of 0.5ppm. Treatment of 0.5ppm boron supply indicated that the leaves and barks contained more phospholipid, protein, sugar, RNA and proline than treatment of 0.01ppm boron supply in nutrient solution. The cuttings grown in boron supply nutrition have a sufficient tolerance at -10$^{\circ}C$ and -15$^{\circ}C$ for 24 hours while cuttings grown in boron-deficient nutrition have a weak tolerance at the same condition. As mentioned above, we can conclude that the effect of boron deficiency on root development is much severe and the relationship between the lack of boron and cold damage is very closely related.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.101-105
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• 2015

Efficacy of novel nematicide, imicyafos GR was evaluated against two species of the root-knot nematodes in pot and greenhouse conditions. When tested in pots, the population of Meloidogyne incognita and M. hapla was reduced sixty days after treatment, with mortality rate of 91.5% and 90.6%, respectively. Suppression effect of imicyafos GR on root galling in tomato was tested. The number of root galls caused by M. incognita and M. hapla was reduced 60 days after nematode inoculation, with the efficacy of 94.2% and 95.1%, respectively. Under greenhouse conditions planted with watermelon, melon, cucumber, and tomato, the efficacy of imicyafos GR on M. incognita persisted up to 60 days after treatment, showing 90% of control efficacy. Moreover, the number of root galling was more reduced than fosthiazate treatment, with the potential as a control agent.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.610-616
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• 2011

Clubroot disease caused by Plasmodiophora brassicae, induces damage to cruciferous vegetables worldwide. For control of the disease, many CR (clubroot resistant) $F_1$ hybrid cultivars of Chinese cabbage have been bred and released in Korea. In this study, we determined the race of 10 field isolates of P. brassicae collected from ten regions in Korea using Williams' differential varieties and investigated the degree of resistance of 25 commercial CR cultivars of Chinese cabbage to the isolates. The clubroot pathogens were assigned into two (HS and YC), two (HN1 and HN2), two (DJ and SS) and four (GS, GN, JS, and PC) isolates for race 2, race 4, race 5, race 9, respectively. All CR cultivars showed similar response, resistant or susceptible, to each isolate and the P. brassicae isolates were divided into two groups. Among them, the DJ, GS, GN, HS, and JS isolates could not infect the CR cultivars. In contrast, the SS, HN1, HN2, PC, and YC isolates caused severe clubroot disease on the CR cultivars like susceptible cultivars. Even though they belong to the same race, the CR cultivars showed a different response to the pathogens. The results suggest that the breakdown of CR in Chinese cabbage has already occurred in cultivation areas of Korea and resistance source introduced in CR cultivars may be very limited. In addition, it is likely that resistance genes of Williams' differential varieties to P. brassicae are different from the gene of CR cultivars of Chinese cabbage used in the study.

• Journal of Korean Society of Rural Planning
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• v.5 no.1 s.9
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• pp.95-103
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• 1999

The purpose of this study is to find out the distribution of underground biomass and its soil stabilizing effects. Bamboo and grass were examined and compared. 1. Thirty 'soil & root' samples were collected to the depth of 30cm with Impact-corer, and then divided into three sections(0-10cm, 10-20cm, 20-30cm). Each piece had a volume of $950cm^3$ and the underground biomass was separated from the soil particles by washing with flowing water. The average underground biomass rates of bamboo and grass were 10.8% and 4% of each sample, respectively. The rate of grass root biomass declined with depth, but the bamboo root biomass was at peak at around 20cm depth. 2. The shear strength was measured with con-penetration tester at each sample collecting site. Three measurements were made at each depth(0-10cm, 10-20cm, 20-30cm) and were compared with the impact counts needed to insert the corer to the depth of 30cm. The shear strength has clear correlations with underground biomass. The more underground biomass, the higher shear strength. The shear strength of bamboo was about three times larger than the grass.

• The Korean Journal of Soil Zoology
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• v.8 no.1_2
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• pp.23-26
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• 2003

A neem based product, Suneem-G (granules) alone as well as in combination with urea was tested against root-knot nematode, Meloidogyne incognita, on okra (Abelmoschus esculentum) in clay pots of 20-cm-diameter, containing 2 kg sterilized soil, inoculated with 2,000 freshly hatched second stage juveniles (J$_2$) of M. incognita. Application of different dosages of Suneem-G with or without urea significantly reduced nematode population and incidence of galling on okra roots and increased vegetative plant growth compared with the untreated control. Suneem-G with urea was the most effective and its effect increased with the increase of dosage. Suneem-G 6 g＋urea 25 g per pot gave maximum plant growth and root gall reduction, as plants shoot and root lengths were increased by 84 and 58% and root galling was reduced by 58%, respectively. The lowest dosage of Suneem-G alone, 2 g per pot increased shoot and root lengths of plants by 25.7 and 17%, respectively, and reduced root galling by 24%. The lowest effect was recorded in the pots treated with 25 g urea alone; shoot and root lengths were increased and root galling was decreased by 14% each.

• Food Science and Preservation
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• v.17 no.1
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• pp.123-130
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• 2010

We compared physiological activities in reflux extracts from Liriope platyphylla leaves and roots. The water extract of roots had the highest solid extraction yield of 53.96%. The greatest level of total polyphenols was 186.88 mg/g in methanol extracts from leaves, whereas water extract from leaves showed the highest concentration of flavonoid compounds, at 159.29 mg/g. The leaf extract had 97.42% of the electron-donating ability (EDA) of the positive control, at 0.5 mg/mL. The superoxide dismutase (SOD)-like activity of water extract of leaves was 9.75% of the positive control value, at 1.0 mg/mL. The nitrite scavenging ability of methanolic extract from leaves was highest, at 40.56% of the positive control level at pH 1.2 and a concentration of 1.0 mg/mL, whereas root extracts were ineffective in this regard. Inhibition of xanthine oxidase by leaf extracts was more than 99% of the positive control value at 1.0 mg/mL, whereas water and methanolic root extracts had activities of 93.75% and 68.47%, respectively. When tyrosinase inhibition was examined, the water extract of leaves had 22.80% of positive control activity but methanolic extracts were inactive. These results indicate that leaves of L. platyphylla will be more useful for development of functional products than the roots, which are used to make medicinal preparations.

• Research in Plant Disease
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• v.17 no.2
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• pp.161-168
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• 2011

To establish simple and reliable screening method for resistant radish to Plasmodiophora brassicae Woron. using soil-drenching inoculation, the development of clubroot on radish seedlings inoculated with P. brassicae GN-1 isolate according to several conditions such as inoculum concentration, plant growth stage and incubation period after inoculation was studied. To select resistant radish against clubroot, 10-day-old seedlings were inoculated with P. brassicae by drenching the roots with the spore suspension of the pathogen to give $1{\times}10^9$ spores/pot. The inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days then cultivated in a greenhouse ($20{\pm}5^{\circ}C$) for 6 weeks. Under the optimum conditions, 46 commercial cultivars of radish were tested for resistance to YC-1 (infecting 15 clubroot-resistant cultivars of Chinese cabbage) and GN-1 (wild type) isolates of P. brassicae. Among them, thirty-five cultivars showed resistance to both isolates and one cultivar represented susceptible response to the pathogens. On the other hand, the other cultivars showed different responses against the tested P. brassicae pathogens. The results suggest that this method is an efficient system for screening radish with resistance to clubroot.