• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.504-508
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• 1983

To define the effects of synthetic auxins on rooting from the ginseng stern cutting and the root growth in diameter after the rooting of the cuttings, stern cuttings with palmate leaves obtained from seedlings and 2-year old ginseng plants were planted in rooting media treated with solutions of the synthetic auxins. All the roots induced from the cuttings were adventitious fibrous roots at first, but a few adventitious roots of the cutting were thickened in diameter to over 2 to 3mm at 120 days after cutting and the rest of them disappeared. IBA was the most effective auxin for rooting and root growth in diameter after rooting from the cuttings. The shape of the roots that thickened in diameter could be divided into two types. Both types of thickened roots were fully lignified at 120 days after cutting and those thickened roots did not dry up or die by July of the next year, however no rhyzomes or shoot primodia were induced from them.

• Restorative Dentistry and Endodontics
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• v.31 no.2
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• pp.79-85
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• 2006

To evaluate the effect of vital tooth bleaching agent and alcohol pretreatment on dentin bonding, flat dentin windows were produced on the buccal side of the crowns of fifty-five extracted, human premolars. A bleaching gel, $Opalescence^{(R)}$ with 10% of carbamide peroxide (Ultradent Product, USA) was daily applied on the teeth of three experimental groups for six hours for 10 consecutive days, while teeth of a control group were not bleached. After 6 hours of bleaching gel application the specimens were washed and stored in saline until the next day application. After application of $One-step^{(R)}$ dentin bonding agent (Bisco, USA), $Z-250^{(R)}$ resin (3M-ESPE, USA) was bonded to dentin with a mount jig. Shear bond strength was measured with an Instron machine (Type 4202, Instron Corp., USA) after 24 hours. The results were analyzed using one-way ANOVA and Duncan's multiple range test at p < 0.05. Immediate bonding group showed significantly lower bond strength than un-bleached control group (p < 0.05). Ethanol-treated group showed significantly higher bond strength compared to immediate bonding group (p < 0.05). However, the bond strength of the ethanol treatment group was lower than that of the un-bleached control group (p < 0.05). There were no significant difference in shear bond strength between the 2-week delayed bonding group and the ethanol-treated group (p > 0.05) and between delayed bonding group and un-bleached control group (p > 0.05). In the condition of the present study. it seems that alcohol pretreatment after bleaching procedure can reduce the adverse effect of vital bleaching agent on dentin bonding.

• Research in Plant Disease
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• v.17 no.2
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• pp.148-154
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• 2011

This study was conducted to control the seed borne pathogens (Alternaria spp.) of carrot and to examine the seed germination rate by using 13 environment friendly agricultural materials instead of conventional chemicals for organic cultivation. The growth inhibiting effects on pathogens showed the different responses according to each agricultural material and effective 7 materials against seed borne pathogens were selected. Among 7 materials, the carrot seeds sterilized with plant extracts, Tanger Stop and Land Saver were not germinated at all. The germination rate of seeds sterilized with other materials showed the similar levels with reference chemical (Benlate-T) and non-treated seeds. Infection rates of seeds sterilized with seaweed extract, Bellopper for controlling A. radicina and plant extract, Ssial-100 for A. dauci were similar or low infection rate compared with reference chemical. The germination rate and root length of seeds sterilized with Bellopper and Ssial-100 was similar or superior to those of chemical sterilized seeds. The optimal condition seemed to be a little bit different depending on the concentration of materials. As a result, the sterilization of carrot seeds by using the environment friendly materials could be effectively utilized as a technology to inhibit the infection of seed-borne pathogens.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.26-32
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• 2014

We investigate the effect of post-conditioning periods and seed orientation on the vigor of cucurbit seeds with dry heat treatment (DHT). All the dry-heat treated seeds exhibited varying degree of seed vigor decreases. In general, pumpkin seeds showed less vigor decreases than the bottle gourd seeds. When the dry heat treated seeds were germinated after post-conditioning for 0, 30, and 120 days, the percentage of germination was enhanced by increasing the period of post-conditioning and the efficiency of post-conditioning differed by crop and cultivar. In both bottle gourd and pumpkin, the vigor of seeds placed in vertically upward and horizontal orientations was higher than that of the seeds placed in the vertically downward orientation. The results suggested that the vigor of dry-heat treated seeds could be improved by applying the proper post-conditioning and seed orientation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.201-210
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• 1990

This study was carried out to determine the effect of mixture of hymexazole and metalaxyl(Tachigarace) on the growth and reducing low temperature injury in rice seedlings. The amount of mixture of hymexazole and metalaxyl (Tachigarace) applied to reduce low temperature injury was 0, 9, 18 and 36mgr per pot (5${\times}$15${\times}$10cm) by soil incorperation befor sowing. Aging seedling was investigated on the growth responses by the application of 0.36gr mixture of hymexazole and metalaxyl (Tachigarace) per tray (30${\times}$60${\times}$3cm) after cutting of leaf at 35 day-old seedling. Rice seedlings treated with mixture of hymexazole and metalaxyl (Tachigarace) were better in the growth of top and roots, dry weight, erecting and rooting abilities than untreated seedlings. The effective amount of mixture of hymexazole and metalaxyl (Tachigarace) to increase erecting and rooting abilities was 18 mgr per pot. Under low temperature treatment, 12$^{\circ}C$, the leaf discoloration and dead leaf percent of rice seedlings were markedly decreased in the seedlings treated with mixture of hymexazole and metalaxyl (Tachigarace) as compared with untreated seedlings. The more amount of mixture of hymexazole and metalaxyl (Tachigarace) upto 36mgr per pot, the more effective on the low temperature injury in the seedling. The effect of mixture of hymexazole and metalaxyl (Tachigarace) to reduce low temperature damage in rice seedlings was mainly due to decreasing less physiological activities on the expanding leaf area and rooting, transpiration, stomatal diffusion and chlorophyll content of the leaves and oxygen consumption of the roots. Plant height, top dry weight and leaf area of aging seedlings were increased with mixture of hymexazole and metalaxyl (Tachigarace) treatment and leaf cutting as compared with untreated seedling and intact leaf, respectively. The ratio of missing hill of aging seedling was increased with increasing the period of growing seedling and was decreased due to leaf cutting, whereas the effect of mixture of hymexazole and metalaxyl (Tachigarace) application was not observed. Rooting ability of aging seedlings was decreased with lengthening of the period of raised seedling and was increased with mixture of hymexazole and metalaxyl (Tachigarace) treatment and leaf cutting.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.351-358
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• 2006

This study was conducted to evaluate herbicidal properties of picolinafen in terms of crop safety, weed control spectrum, application window, residual efficacy and resistant weed control. Herbicidal phytotoxicity of picolinafen to wheat and barley was greatest when applied at 0 days after sowing (DAS), but decreased significantly as plant growth advanced. Picolinafen showed greater activity against broadleaved weeds than grass weeds. Picolinafen showed highest activity when it was applied at early post emergence timing (5 to 15 DAS), and showed significantly decreased activity at 20 DAS application. The $LT_{50}$ values (the period from application required for residual control by 50%) was 9.3 and 6.5 days against Digitaria ciliaris and Brasica naus at 60 g ai $ha^{-1}$, respectively. Picolinafen showed similar activities against both triazine resistant and sensitive Amaranthus retroflexus. Collectively, picolinafen appeared to have a good fitness to control resistant broad leaved weeds control by early post emergence application.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.63-69
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• 2000

In order to establish a micropropagation system for buffalo gourd (Cucurbita foetidissima ) and common milkweed (Asclepias syriaca), the effects of several plant growth regulators and culture temperature on shoot multiplication and rooting were investigated. In buffalo gourd, the greatest number of shoot from shoot tip culture and well growth of formed shoot were obtained on the MIS medium supplemented with 1.0 mg/L BA and 0.3 or 0.6 mg/L IAA. Whereas kinetin and 2iP were not effective for shoot multiplication in vitro. It was found that 22$^{\circ}C$ and $25^{\circ}C$ were suitable for shoot multiplication. Roots were easily formed by the addition of auxins, especially 1.0 or 2.0 mg/L IBA and 2.0 mg/L IAA. Over 90% of plants survived successfully after being transferred into the field. In common milkweed, BA was more effective than kinetin or 2iP for its micropropagation in vitro. The increased shoot weight and number of nodes per shoot were obtained on the medium containing 3.0 mg/L BA and 0.3 or 0.6 mg/L IAA. But 2iP promoted the shoot elongation. In addition. common milkweed was sensitive to culture temperature in vitro. Temperature around 22$^{\circ}C$ was favorable for shoot multiplication and growth, whereas temperature higher than $25^{\circ}C$ usually reduced the rate of shoot survival rate.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.116-122
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• 2001

An isolate of the prospective hyperparasite, Ampelomyces quisqualis 94013 (AQ94013) was selected for the use of biological control of cucumber powdery mildew caused by Sphaerotheca fuliginea. Examination for the parasitism processes by scanning electron microscopy and light microscopy showed that conidia of AQ49013 germinated on conidia, conidiophores and hyphae of Sphaerotheca fuliginea four hours after inoculation. Appressorium-like structures were developed and attached to the hyphae of S. fuliginea seventeen hours after inoculation. Hyphae of AQ94013 penetrated into hyphae of S. fuliginea twenty-four hours after inoculation. Pycnidia of AQ94013 were produced in the hyphae and the basal part of conidiophores of S. fuliginea fourty four hours after inoculation. The pycnidia of AQ94013 matured foully eight hours after inoculation, and the conidia were discharged from the ostioles of the pycnidia fifty two hours after the inoculation. At the same time, hyphae and conidiophores of S. fuliginea were distorted and died. Also, concentrated culture filtrate and culture filtrate of AQ94013 had not suppressed the cucumber powdery mildew fungus as water treatment. Therefore, mode of action of AQ94013 was assumed to be parasitism on powdery mildew fungi.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.536-538
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• 2023

수출의존도가 높은 한국은 코로나19 팬데믹, 우크라이나-러시아 전쟁 등 대외환경의 변화에 따른 수출 여건에 민감할 수 밖에 없는 환경이다. 이에 발 빠르게 대응하기 위해 정확한 수출증감률 예측이 필요하며 이를 가장 잘 수행할 수 있는 예측모델을 찾고자 한다. 수출에 영향을 끼치는 주요변수 선정 후, min-max 정규화를 시행하고 변수간 상관계수와 다중공선성 확인을 통해 변수를 축소했다. 그리고 머신러닝 예측모델로 많이 사용되는 Linear Regression, Decision Tree, Gradient Boost Regressor, Random Forest 4가지 모델에 대입하여 수출 증감률 예측 정확도를 비교했다. 그 결과, Linear Regression의 MSE가 0.087로 가장 낮아 제일 우수한 모델이라는 결론에 도달했다.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.27-31
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• 1965

The aim of this work was to investigate how the mulberry shoots grew well when the mulberry branches were cut down, in hight, 1/3, $\frac{1}{2}$ and 2/3 of them, respectively, just before the Spring budding. The results obtained are as follows: 1. The rate of un-sprouted buds decreased sharply down as much as half of the control if the mulberry branches were cut off. The treatment, 1/3, was best one of various cut down sizes and the un-sprouted buds concentrated on the lower parts of the branches. 2. Even though the branches were cut down, at first it seemed flat to accelerate the sprouting of buds, but rather to have a tendency to become late. The speed of leaf growth, however, became faster after the sprouting. It took 7~9 days from the beginning of buddings to the 5th full grown leaf, and.7 days for the shortest one in the treatment, 2/3, when compared with 16 days of the control. 3. If the branches were cut down, the growth of the new sprouts was accelerated. For 45 days (on 5th of May to on 10th of June), therefore. the shoots had grown up to 1.6～2.5 times of the control, 34cm long. The shoots of which the branches were cut down at 2/3 of them were longest (83cm). Furthermore. the speed of shoot growth of cut-down branches was faster than that of the control. 4. In the increased rate of the number of the mulberry leaves, there was not significant difference between the control and the treatments. 5. The total amount of shoot growth showed considerably much more in the treatments than in the control. The successing growing shoots of treatment, 2/3 were little in a number but longest per one shoot in mean shoot length. 6. It seems to be much available that we may cut down branches at 2/3 of them in order to get the scions for the cutting as soon as possible.