• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.253-259
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• 2008

Soil environmental conditions can affect nutrient availability during growth stage of tree fruit. We investigated the cause of disorderd fruit by the influence of soil chemical properties in orchard soil, composition of mineral nutrient in leaves and fruit to occur physiological disorderd fruit at four locations (Ulsan, Gyeongju, Pyeongtaek, Ansung) compared to healthy. There were significantly different (P=0.05) in exchangeable Ca, K, Mg and total nitrogen content in orchard soil between physiological disordered fruit and healthy fruit. The exchangeable Ca content in orchard soil caused by physiological disordered fruit was statistically lower than that of healthy fruit. However, exchangeable K, Mg and total nitrogen contents were higher than that healthy (P=0.05). There was a significant difference (P=0.05) in Ca content between physiological disordered fruit and healthy. Ca content in fruit flesh of physiological disorderedfruit was statistically lower than that of healthy. The physiological disordered fruit was a higher ratio of Mg/Ca in fruit flesh and peel compared to healthy fruit and also the ratios of N/Ca and K/Ca in a leaf were higher. The negative correlation between Ca and K, and Ca and Mg was detected in the fruit flesh of physiological disordered fruit. Therefore, we concluded that insufficient Ca content in fruit may cause 'the physiological disorder' pomelo disease and high content of N, exchangeable K and Mg ion in the soil solution might be disturbs exchangeable Ca ion to be absorbed in fruit.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.40-45
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• 2018

Potassium in vegetables is known to have an adverse impact on a patient with chronic kidney desease. However, since vegetables also contain many other nutrient, consumption of vegetables by these patients is inevitable. The objective of this study was conducted to develop a fresh lettuce which contains low level of potassium for nephropathy in a closed-type plant factory system. Lettuce of "Charles" was used for experiment. The plants were cultivated in hydroponic system with a 16-h photoperiod at $15-21^{\circ}C$, 65% RH, $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(LED W:R, 9:1) and $600-650mg{\cdot}L^{-1}$ $CO_2$ during 28 days. Nutrient solution which contains 1%, 5% and 10% potassium compared to conventional composition were supplied at 1 week and 2 weeks before harvest. The content of potassium and macro elements in leafy vegetables were analyzed by ICP emission spectroscopy after harvest. The potassium content in leaf of the 2 weeks before harvest treatment was significantly lower at than control. There were no significant differences between control and treatments in fresh weight and number of leaves. But there were differences among treatments. Considering the vegetable amounts consumed by nephropathy patients, the supply of nutrient which contain 1% and 5% potassium at 2 weeks before harvest was suitable for low potassium lettuce production. This study indicated that low potassium lettuce could be produced by developed nutrient composition and supply method.

• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.305-312
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• 2010

During a last decade, the introduced traits in commercialized GM crops have been diversified from a simple trait such as herbicide resistance gene or insectresistance gene which are related to the crop production into more complicated traits such as modification of fatty acid or essential amino acid composition, modified coloring pattern of flower. In addition, it was investigated that several other GM crops bearing more refined traits expected to lead next generation are also awaiting for risk assessment (RA) or under field test for the preparation of RA in the near future. These GM crops include abiotic stress resistance including drought or cold, increased biomass, production of bioethanol or diesel, production of pharmaceuticals or functional materials for industrial. In particular, in 2008 and 2009, it was reported that the highest number of GM crops for molecular farming are under developed in laboratory or green house level in all the world. Likewise, in Korea, 171 events from 49 plant species are under developed to introduce several important traits. At present, about 10 events are under field test to select elite lines for RA application. For the first time, herbicide resistance turfgrass developed by Korean research team has been submitted for RA and currently under requested for additional data. Moreover, GM rice resistant to leaf roll (folder) disease is expected as a next event to be submitted for RA application.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.38-43
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• 2000

As the first step of a research on the establishment of control strategy for grapevine diseases and insects, the current status of pest control and yield losses by them were surveyed from grapevine growers of Korea. For insects, the most difficult to control was a grapevine stem borer and a grapevine clearwing moth was the next. On the other hand, several diseases including anthracnose, downy mildew, powdery mildew, bird's eye rot, leaf blight, were answered by the growers. The occurrence of the pests varied to the cultural practices. Yield loss was more serious in rainfall intercept culture than in plastic film house culture and diseases caused more loss in yield than insects did. However, the grapevine grower's potential for the identification of the kinds of pests was not high enough. When the pest was observed, the growers consulted mainly with local pesticide dealers or neighbouring growers and usually applied the pesticides prescribed by the dealer. More than half of the growers did not use pest control calendar, and most of the growers applied pesticides before any symptom appeared. Also, more than half of the growers applied mixture of at least more than 1 kind of pesticide and nutrients. Insecticides were applied less than 5 times during the season, but it was more than 6 times for fungicides. In the pesticide selection, the growers checked control effect first, regardless of the registration, and the pest control cost per unit area varied very much depending on the growers.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.376-382
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• 2014

The soluble loess-sulfur mixture allowed standing to remove insoluble component materials for five weeks after manufacturing. We decreased the pH level of soluble loess-sulfur mixture at pH 1.0 modified with decreasing 25% sodium hydroxide than original content. The pH ranges of soluble loess-sulfur mixture solutions were adjusted to pH 5.0-pH 11.0 (pH 1 unit) with brown rice vinegar (pH 2.8). The pH of original loess-sulfur mixture was about pH 13 and damaged the foliar parts and young leaves of tomato after twice application. These stock solutions can be diluted 500:1 with tap water to make a 0.05% working solution and were sprayed two times with 7 days interval to the leaf and stem of tomato, which were spontaneously infected with E. cichoracearum. Control efficacy of powdery mildew ranged from 85% to 90% at 7 days after first application. After second application, each loess-sulfur mixture solutions adjusted pH level significantly suppressed the powdery mildew disease in tomato. Consequently, loess-sulfur complex adjusted pH level with brown rice vinegar was suggested to be low in acute toxicity at all different pH values and suggested to use an agent for control of tomato powdery mildew in organic farming.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.1
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• pp.53-56
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• 2007

A new orchardgrass (Dactylis glomerata L.) variety named "Kordione" has developed by the National Livestock Research Institute (NLRI) in 2005. To develope a new variety of orchardgrass, 5 superior clones were selected and polycrossed for seed production. Various agronomic growth paramaters and forage production of "Kordione" were examined at Suwon from 2001 to 2002. During 2003-2005, regional trials were conducted at Suwon, Pyungchang, Youngju, Iksan, and Jeju. "Kordione" showed a medium type growth habit in fall and spring, and short in length of flag leaf and upper internode. Plant height of "Kordione" was similar to that of standard variety, "Ambassador" and heading date was 2 days later than 10th May compared to Ambassador. "Kordione" showed enhanced winter hardiness, lodging tolerance and disease resistance compared to Ambassador. In addition, dry matter yield (12,081 kg/ha) of "Kordione" was also higher (11%) than that of the Amabassador. However, nutritive value was similar in both varieties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.1-6
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• 2008

Korditwo is a new orchardgrass(Dactylis glomerata L.) variety developed by the National Institute of Animal Science(NIAS) in 2005. To develope the new variety of orchardgrass, 5 superior clones, Dg8533, Dg9518, EDg9133, U8504 and U8519, were selected and polycrossed for seed production. That synthetic variety was designated newly as "Korditwo", and it's agronomic growth characteristics and forage productivity were examined at Suwon from 2001 to 2002, and regional yield trials were conducted in Suwon, Pyungchang, Youngju, Iksan, and Jeju from 2003 to 2005, respectively. "Korditwo" showed medium type growth habit in fall and spring and short in length of flag leaf and upper internode. Plant height of "Korditwo" was similar to that of standard variety, "Ambassador" and heading date was 4 days later than 14th May compared to Ambassador. Characteristics such as winter hardiness, lodging tolerance, disease resistance of "Korditwo" were stronger or better than those of Ambassador, specially in winter hardiness and lodging tolerance. "Korditwo" showed 10% higher dry matter yield(11.3 ton/ha) compared to Amabassador. Nutritive value was appeared to be similar in both varieties.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.80-80
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• 2018

Hosta is a genus of the family Asparagaceae and distributed in East Asia. There are six Hosta species (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) native to Korea and among them, four species (H. minor, H. jonesii, H. venusta and H. yingeri) are endemic to the Korea peninsula. Hosta is generally propagated by seed, crown division or tissue culture. However, tissue culture is a more efficient method to mass proliferation, a new cultivar development and disease-free plantlet production in a limit time. Hence, we conducted this study to evaluate the influence of various plant growth regulators (PGRs) treatments on the induction of callus and somatic embryo of the six Hosta species. Leaf, petiole and root were used to select optimum tissue culture explants. Petiole explants thus only were used for callus induction and somatic embryogenesis with TDZ (0.1, 0.5 or 1.0mg/L) and NAA (0.1 or 0.5 mg/L) combinations. After 12 weeks of culture, the highest rate of somatic embryogenesis was achieved on modificated MS medium containing 1.0 mg/L TDZ and 0.1 mg/L NAA in H. capitata and H. minor (15.5%, respectively), 0.1 or 0.5 mg/L TDZ and 0.1 mg/L NAA in H. jonesii (22.2%), 1.0 mg/L TDZ and 0.5 mg/L NAA in H. yingeri (26.7%), and 0.1 mg/L TDZ and 0.5 mg/L NAA in H. venusta (53.3%). H. clausa showed very low effect on somatic embryogenesis by PGRs; 2.2%. There was interspecies difference to PGRs respond for callus and somatic embryo induction. Regenerated multiple shoots and plantlet of H. minor, H. jonesii, H. venusta and H. yingeri were obtained via somatic embryogenesis.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.43-47
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• 1987

Effect of percent penetration and hyphal growth on lesion formation was evaluated at 23/15C (day/night), 29/21C regimes and greenhouse condition (33-23C) using three rice cultivars, Aichi-asahi, Toyotama and Yamabiko with 6 isolates of Pyricularia oryzae. Percent penetration at 72hr and 96hr after inoculation was highly significant with lesion formation at any temperature regime. At the same time, number of appressoria that exceeded hyphal growth value 11 was also highly significant with lesion formation. However, number of appressoria that exceeded hyphal growth value 30 was significant only at 72hr after inoculation at 29/21C regime. In general, statistical fitness of the model was higher at 23/15C regime than at 29/21C regime or a greenhouse condition. These series of phenomenon were more apparent in a susceptible cultivar Aichi-asahi.

• 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.