• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.141-154
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• 2012

This study was launched to verify the effective composition of plant species and its management program most suited for the dredged soiled area near Nakdong River Site 14. The improvement methods of planting base and the composition of plants such as silver grass, reed, and some colonies in aesthetic effect were studied. To search the management methods to decrease the confining pressure risen from the burried seeds which would consequently harm the previously seeded plants, experimental construction process was measured on the site. The purpose of this experiment was to figure out which part of the improvement on the plant base has the most significant effect for the revegetation of infertile, dredged soil, to verify the easily seeded, developing plants among seeded plants, and finally, to find the restoration model using plants near the dredged soil around riverside. 8 seeded plants and 23 invaded species were appeared which among the emerged plants, development of Aster yomena MAKINO, Lotus corniculatus var. japonica Regel, Trifolium repens L, and Dianthus longicalyx Miq were proved to be brought up well. Difference risen from the seed composition were not noticeable until 150day since the germination was proceeded mainly by Aster yomena MAKINO. The experimental plot with dredging sand+organic fertilizer method of construction and dredging sand+soil conditioner method showed most development while the effect of the plot with only the soil base of dredging sand stayed low. Another important method for the management of infertile, dredged soil base would be the removal of disturbing species which the experiment showed the tied relationship between the removal of disturbing species and development of seeding plants. Although this study was carried out focused on the Nakdong River Project, the study suggests the general management program that the removal of disturbing species such as Humulus japonicus Sieboid & Zucc. and Pueraria lobata (Willd.) Ohwi in times around rainy season(60days after seedling) would be effective for the easy growth of revegetation plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.35-42
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• 1976

In Korea, two types of rice varieties are being cultivated widely, Japonica and Japonica-Indica cross. Generally speaking, the latter shows weak cold tolerance than the former and so brought about many problems in cultural practices. This study was conducted to investigate the effect . of various temperature conditions on rice seedlings growth, especially the contents of chlorophyll and the percentage of nitrogen. And the result obtained indicated the varieties of Japonica-Indica intend to weak cold tolerance than Japonica varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.353-358
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• 2008

The purpose of this study was to examine the effects of black polyethylene film mulching and soil conditioners on the growth, yield, and flavonoids biosynthesis of mungbeans. The seedling stand rate, plant height, and pods per plant were 98%, 61 cm, and 15.1, respectively, when the mungbean grown black polyethylene film mulches. They were greater than these results when the without mulches was applied by 13%, 9 cm, and 1.8, respectively. Mungbean grown with black polyethylene film mulches ($243\;kg{\cdot}10a^{-1}$) exhibited 38% more seed yield than without mulches ($176\;kg{\cdot}10a^{-1}$). However, no significant difference in contents of vitexin and isovitexin of mungbeans between with black polyethylene film mulches and without mulches was observed. Among soil conditioners, standard fertilizer+oil cake and standard fertilizer+mineral powders increased number of pods. The standard fertilizer+oil cake showed the highest seed yield (119%) of mungbean when it mixed with standard fertilizers, and followed by mineral powders (115%). The mixed combinations of oil cake or mineral powders also seem to have affected the biosynthesis of vitexin and isovitexin, whose content in mungbeans was significantly more.

• Research in Plant Disease
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• v.24 no.3
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• pp.193-201
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• 2018

Pectobacterium carotovorum subsp. carotovorum (Pcc) causes bacterial soft rot on a wide range of crops worldwide, especially in countries with warm and humid climates. This study was conducted to establish an efficient screening method for resistant cultivars of radish (Raphanus sativus) to bacterial soft rot. Resistance degrees of 60 commercial radish cultivars to the Pcc KACC 10421 isolate were investigated. For further study, six radish cultivars (Awooriwoldong, YR Championyeolmu, Jeonmuhumu, Bitgoeunyeolmu, Sunbongaltari, Housecheongok) showing different level of resistance to the bacterium were selected. The development of bacterial soft rot on the cultivars was tested according to several conditions such as incubation temperature, seedling stage of radish, inoculum concentration to develop the disease. On the basis of the results, we suggest that an efficient screening method for resistant radish to Pcc is to inoculate twenty-day-old seedlings with a bacterial suspension of Pcc at a concentration of $8{\times}10^5cfu/ml$ and then to cultivate the plants in a growth room at $25^{\circ}C$ and 80% RH with 12-hour light per day.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.106-115
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• 1998

This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.784-788
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• 2015

A new cultivar 'Picnic' originated from an artificial cross between 'Fuji' and 'Sansa' at National Institute of Horticultural & Herbal Science in 1994. The cultivar was preliminarily selected among the elite siblings for its high fruit quality in 2003. After regional adaptability tests in five districts for four subsequent years as 'Wonkyo Ga-34', it was ultimately selected in 2008. Optimum harvest time is late September. Mature fruit has mean weight of 233 g and is conic with light red skin on a greenish yellow ground and yellowish white flesh. The fruit contains a favorable total soluble solids content at $13.8^{\circ}Brix$ and titratable acidity at 0.43%, which results in gustatory harmony between sugars and acids. It is not resistant to bitter rot or Marssonina blotch. 'Picnic' exhibits a physiological cross compatibility with leading cultivars such as 'Fuji', 'Hongro' and 'Tsugaru'. Tree topology is semi-spreading with a weak growth habit.

• Journal of Korean Society of Forest Science
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• v.25 no.1
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• pp.80-84
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• 1975

The seeds, scions and plants of chestnut tree (Castanea. crenata) and Chinese chestnut tree (C. bungeana) were irradiated by gamma ray in order to know their biological effects on germination, plant growth and mutation at several accumulative doses and dose rates. The results of this study could be summarized as follows: 1. In general, the radio-sensitivity of scions was more sensitive to irradiation, showing 50% reduction dose of the control for grafting percentage at 3.1 kR as compared with 4.6 kR for the above reduction dose in germination rates of seeds. 2. The seeds treated by 5 kR dose resulted in some albino mutants at a rate of 0.84%. There was a general tendency that the seedling height reduced significantly as the irradiation dose increased. 3. The scions treated by an acute irradiation showed their 50% reduction dose in grafting at 3.2 kR for Chinese chestnut and at 3.1 kR for chestnut, respectively, while their irradiation doses increased three times, having 10.2 kR for the 50% reduction dose in the case of semi-acute irradiation. 4. When Chinese chestnut trees were irradiated during their dormant period with a total dose of 7.5 kR to 4.9 kR at a dose rate of 150 R to 98 R per day, there were induced giant leaf bud-sports at a frequency of 16.6%. The averag leaf area of the giant leaf bud-sports were measured at 96.36 square centimeters, while the area of normal leaf was only 26.28 square centimeters.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.724-732
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• 2020

Phytophthora capsici is the organism that causes Phytophthora blight which infects red pepper plants prolifically, ultimately leading to crop loss. A previous study revealed that Enterobacter asburiae ObRS-5 suppresses Phytophthora blight in both red pepper and Ligularia fischeri plants. In order to determine whether the induced systemic resistance (ISR) was triggered by pre-infection with the ObRS-5 strain, we conducted quantitative PCR using primers for PR1, PR4, and PR10, which correlate with systemic resistance in red-pepper plants. In our results, red pepper plants treated with the ObRS-5 strain demonstrated increased expression of all three systemic resistance genes when compared to controls in the glasshouse seedling assay. In addition, treatment of red peppers with the ObRS-5 strain led to reduced Phytophthora blight symptoms caused by P. capsici, whereas all control seedlings were severely affected. Perhaps most importantly, E. asburiae ObRS-5 was shown to induce the ISR response in red peppers without inhibiting growth. These results support that the defense mechanisms are triggered by ObRS-5 strain prior to infection by P. capsici and ObRS-5 strain-mediated ISR action are linked events for protection to Phytophthora blight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.283-288
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• 1982

This experiment was carried out to improve the cultural practices of seedlings and to investigate the proper planting density in aromatic tobacco, Sohang. Two different cultural practices of seedling were employed; Temporary transplanting (TT; Conventional practices) and non temporary transplanting (N.T.). Vinyl pot sizes were $3.5cm{\times}3.5cm, \;4cm{\times}4cm$ and $5cm{\times}5cm$ Plants per hole were 1, 3, 5, 7 and 9. There were little difference among the vinyl pot sizes in all characters except the survival ratio. But it may be little problem on cultural practices by 7 plants per hole in $5cm\times$5cm vinyl pot. There were not significant in price per kg, yield per 10a and value per 10a between two cultural practices of seedlings and among three pot sizes. Mildness and filling power were increased by increasing the plants per hole. Combustibility of 5-9 plants were better than those of 1-3 plants per hole. The growing of 6 seedlings per hole in $5cm\times$5cm vinyl pot by non temporary transplanting resulted the best cultural practices for an aromatic tobacco, Sohyang.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.383-393
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• 1991

Lodging of rice plant is the most important damage by unfavourable weather conditions in rice cultivation. High levels of nitrogen application and growing of Japonica rice variety is one factor to increase the lodging damage. Lodging of rice plant decreasing grain yield; 34% at milky. 21% at dough. 20% at yellow stage. decreasing grain Quality. increasing green rice. and increasing labor cost to harvest. To decrease lodging damage. the lodging resistant varieties will be selected and cultural practices such as amount and time of nitrogen application. planting density. water management. and disease and pest control methods have to be study for the short and strong culm. and good rooting system. Also. application methods such amount and time of plant growth regulators and new types of chemicals will be develop for the reducing lodging of rice plant. To decrease the lodging damage in direct seeding cultivation. first identifying the differences of lodging mechanisms between hand transplanting and direct seeding, second establish the suitable direct seeding methods such as seedling establishement. fertilization. and water menagement.