• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.678-686
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• 1997

This experiment was carried out to develop the mass propagation system for producing plug plantlets using stem cuttings of virus-tree microtubers in potato. Cocopeat, vermiculite, perlite and peatmoss were combined and used as plug nursery media to find out the best combination suitable for the growth of seedlings derived from microtubers. Seedling growth was favored in high temperature (above 2$0^{\circ}C$) and a long-day photoperiod(above 16 hours) condition, while stolons and microtubers formed in outdoor condition. Shoot and root multiplication was not affected by NAA 10mg /1 or IAA 10mg /1 treatment. At the early growth stage of plug plantlets, the number of leaves and roots and the length of root increased significantly when nodes from the upper (near to apex) part of shoots rather than from basal part were taken. But after transplanting, these differences among these characters were not observed. At ninety days after transplanting the plug plantlets in spring time, plant was around 70 to 80cm in height, and the number of stolons and tubers were ten and seven, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.145-154
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• 2022

Due to abnormal weather conditions caused by climate change, natural disasters and damages are gradually increasing around the world. Global climate change as accompanied by warming is projected to exert adverse impact on production of potato, which is known as cool season crop. Even though, role of potato as a food security crop is expected to increase in the future, the climate change impacts on potato and adaption strategies are not sufficiently established. Therefore, this study was conducted to analyze the damage pattern of potatoes due to high temperature treatment and to evaluate the response of cultivars. T he high temperature treatment (35~38℃) induced heat stress by sealing the plastic house in midsummer (July), and the quantity and quality characteristics of potatoes were compared with the control group. T otal yield, marketable yield (>80 g) and the number of tubers per plants decreased when heat treatment was performed, and statistical significance was evident. In the heat treatment, 'Jayoung' cultivar suffered a high heat damage with an 84% reduction in yield of >80 g compared to the control group. However, in Jopung cultivar, the decrease was relatively small at 26%. Tuber physiological disturbances (Secondary growth, Tuber cracking, Malformation) tended to increase in the heat stress. Under heat conditions, the tubers were elongated overall, which means that the marketability of potatoes was lowered. T he tuber firmness and dry matter content tended to decrease significantly in the heat-treated group. T herefore, the yield and quality of tubers were damaged when growing potatoes in heat conditions. T he cultivar with high heat adaptability was 'Jopung'. T his result can be used as basic data for potato growers and breeding of heat-resistant cultivars.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.115-126
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• 2004

The actinomycete strain PK-A41 was isolated from a soil sample from pepper fields in Ko-yang, Korea. The strain PK-A41 inhibited the mycelial growth of some plant pathogenic fungi and oomycete, Alternaria mali, Colletotrichum orbiculare, Fusarium oxysporum f.sp. lycopersici, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora capsici. The presence of LL-diaminopi-melic acid in the cell wall extract and the nucleotide sequence of the 16S rDNA region of the strain PK-A41 was assigned to Streptomyces scabiei. Further morpho-logical, biochemical, and pathological analyses also confirmed the strain PK-A41 to be S. scabiei, which is pathogenic to potato tubers. The maximum antibiotic production of the strain PK-A41 was achieved when grown on the glycerol peptone broth (GPB) medium for 9 days.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.79-88
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• 2008

Twenty-eight of 44 Indian Ceropegia species are endemic and their survival is threatened. As a step towards conservation, we implied in vitro methods for the sustainable propagule production in C. hirsuta, C. lawii, C. maccannii, C. oculata and C. sahyadrica. Effects of explant, growth regulators, sucrose and photoperiod were studied. High frequency microtuber production was achieved with the seedling-apical buds, grown on MS medium containing 4-6 mg $1^{-1}$ BAP, 3-8% (w/v) sucrose, under continuous illumination. Each microtuber, when subcultured proliferated to form a cluster of secondary microtubers. Every primary and secondary microtuber bore at least one shoot-bud and a root primordium. Each tuber (formed with any of the significantly effective treatments) weighed more than 500 mg, enough to plant directly in non-sterilized soils. Microtubers could be produced and proliferated round the year. Proliferation could be solely attributed to in vitro procedures as these plants bear solitary tubers in vivo. Microtubers could be sprouted in vitro to prepare ready to pot plantlets. As, this novel method succeeded for all five species, though they belong to different eco-physiological backgrounds, we recommend its implementation in the conservation programs for a broader range of Ceropegia species, supported by other integrated strategies.

• Research in Plant Disease
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• v.29 no.4
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• pp.399-404
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• 2023

Agricultural activities and the number of farms in the subarctic regions have been increasing annually after the coronavirus disease 2019 pandemic to achieve food self-sufficiency. Potatoes are vulnerable to soft rot bacteria at all stages of production, storage, and transportation. A novel bacterium, Pseudomonas sp. N3-W, isolated from Alaska tundra soil, grows at 5-25℃ and produces extracellular protease(s). N3-W caused necrotic spots (hypersensitivity) in hot pepper leaves and soft rot disease (pathogenicity) in potato tubers. The psychrotolerant N3-W caused significant soft rot symptoms on potatoes at a broad temperature range (5℃, 15℃, and 25℃). In contrast, mesophilic Pectobacterium carotovorum KACC 16999 induced severe rotting symptoms in potatoes at their optimal growth temperature of 15℃ and 25℃. However, it barely produced symptoms at 5℃, which is the appropriate storage and transportation temperature for potatoes. The results of pathogenicity testing imply that psychrotolerant soft rot pathogens from polar regions may cause severe soft rot not only during the crop growing season but also during storage and transportation. Our study indicates the possibility of new plant pathogen emergence and transmission due to the expansion of crop cultivation areas caused by permafrost thawing in response to recent polar warming.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.31-63
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• 1969

A series of experiment was carried out to study on the production of disease-free seed potatoes at the Alpine Experiment Station from 1960 to 1968, which initiated a study of comparison on degeneration of plain warm region and high altitude products and the effect of latent potato virus X (PVX) and potato leaf roll virus(PLRV) on degeneration. Particular observations were made on some aspect of the nature of potato virus disease and its control such as concentrations of PVX, range of host plants, physical properties such as concentrations of PYX, range of host plants, physical properties and carrying effect of insects, by investigating 9 different areas of the main potato producing regions (Kimhae, Taegu, Choongju, Taejoen, Suwon, Kwangju, Chonju, Cheju and Chinju). Highly purified anti-serum was separated and tested for control of the virus disease and also various method of prevention and control of PLRV were observed, using cultivation of sprouted seed tubers, early harvesting method, and systemic chemicals. The results obtained are summarized as follows; 1. Potato yield in the plain region decreased by 32.8~66.3% in the first year cultivation of seed potatoes from colder region, and the rate of virus infection was 92.9 to 95.4%. 2. Plants of three families including, 20 species were susceptible to the PVX, and among the plants Salvia officinalis of a habits only was the carrier while the symptom of Digitalis purpurea of Screphulariaceae was masked. Necrosis and ring spot was occurred in most pJants of the Solanaceae and ring spot symptom also was observed in Nicotiana tabacum L. var. White Burley and in N. glutinosa. 3. The 8$C_2$ strain of virus had the following physical properties; thermal inactivation point, 68-$72^{\circ}C$ : dilution inactivation point, above 1, 000, 000 dilution: ageing in vitro, 240-360 days: and ageing in dry plant tissue, 30 days. 4. Myzus persicae and Oxya spp. did not transmit the 8$C_2$ strain of potato virus. 5. Virus was purified through the ammonium sulphate isolating method, and higher titer value, 1/2048 was obtained through anti-serum test. 6. Inhibition Chenopodiacae on the virus infection of potato was remarkable, and inhibition of local lesion host also was observed. 7, By earlier planting of sprouted seed tubers, growth period could be prolonged by 10 to 12 days. 8. Earlier harvest decreased much the rate of virus infection of seed potatoes. 9. According to the results of aphid control trial using systemic soil insecticides at Kangnung and Taekwanlyung, PSP 204, Disyston and Thimet was effective to aphid control. In particular, control effect of twice treatments of PSP 204 was great. 10. Treatmental effect of those chemicals lasted about 60-70 days. However, single foliar application of emulsified chemicals was not effective to potato virus control. 11. The effect of PSP 204, Disyston, and Thimet on the control of potato leaf roll virus was great, particularly in the case of two treatments of PSP 204, at Kangnung as well as at Taekwanlyung. Higher negative correlationship between the control effect of potato leaf roll virus and potato yield was observed showing the value r=-0.85 at Kangnung, and r=-0.87 at Taekwanlyung. 12. Differences in the control effects among PSP 204, Disyston, and Thimet was not noticed.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.171-175
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• 1994

Physiological changes in Eleocharis kuroguwai Ohwi as affected by bensulfuron-methyl {Methyl 2-[[[[[(4, 6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino] sulfonyl]methyl]benzoate} was determined to relate the characteristics with regrowth behavior. There were no changes in relative growth rate(RGR) during the period of growth cessation after application of bensulfuron-methyl. RGR's of the growth ceseased plants caused at 39 and 51 g/ha began to increase in between 25 and 30 days after application (DAA) and between 30 and 35 DAA, respectively. In untreated plant tuber carbohydrate rapidly decreased right after emergence and almost consumed within 40 days. There was no carbohydrate consumption during the period of growth cessation in bensulfuron-methyl-applied plant, but the content started to rapidly decrease with regrowth. Tuber viability lasted for 30 days in untreated plant, while tubers were viable for 60 and 70 days after application of bensulfuron-methyl at 39 and 51 g/ha, respectively. During the period of growth cessation the plants kept minimum respiration and photosynthesis, but with regrowth respiration and photosynthesis were resumed and rapidly increased.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.21-27
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• 1997

This experiments were conducted to determine the effect of thidiazuron on forming tuberlets and plant regeneration of Pinellia ternata T. by tissue culture. The addition of $5\;{\mu}M$ TDZ to the medium had better regeneration than that of any other treatments of NAA and TDZ. At the combination treatments of NAA and TDZ, as the level of thidiazuron increased, the rate of shoot regeneration was incresed while the increment of NAA concentration inhibited the rate of shoot regeneration. The supplement of $5\;{\mu}M$ thidiazuron produced the best number of micro-tubers per explant and the number of micro-tuber formed was 25 in MS medium and 29 in MG medium on 30 day culture, respectively. Microtuber formation was the best on MG medium with 1.0 mg/l NAA and $5\;{\mu}M$ thidiazuron. MG medium was superior to MS and B5 medium for the growth of tuberlets. Half strength of MS medium with NAA 2 mg/l was the most effective for root formation. Rooting ability on nursery soil of plantlets produced in in vjtro was good as a 80% after 3 weeks.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.8-14
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• 2011

The effect of flooding and soil salinity on the growth of yam (Dioscorea batatas) were studied on the experimantal site temporally established in the south-eastern part of Saemangeum Reclaimed Tidal Land (near Gwanghwal myun, Gimjae-gun, Jellabukdo, Korea). Yam seedlings planted by using aerial bulblet as alternative of sliced tubers, were grown for 20-days and transplanted in black-vinyl mulched ridges (about 20 cm in height) at 70cm interval by $20{\times}60cm$ spacing in the $4^{th}$ of May, 2010. Soil salinity was maintained at lower than 1.2 ds $m^{-1}$ during the growing period and did not result to salt injury in all plants. However, flooding injury very seriously led to plant death and plant mortality rates at $67{\pm}21$ and $82{\pm}9%$ of yam plants in the compost and no compost treatment, respectively, died by heavy flooding during the rainy summer season. The main reasons of the flooding injury included the decreased rainfall acceptable capacity (RAC) after the rising of water table and a slowdown of water infiltration rate after the formation of an impermeable soil crust in the furrow bottom with continuous and heavy downpour during the rainy summer season. The effect of compost treatment was not statistically observed because of the severe spatial difference caused by wet injury, although yam tuber yield was higher at 30 kg $10^{-1}$ in the compost treatment than in the no-compost treatment at 20 kg $10^{-1}$. However, the size of tuber ranged at 1.23 to 1.60 cm in diameter and 3.7 to 5.0 cm in length in all both treatment, which means they are still reproducible for the next cropping season. Conclusively, proper counter-flooding measure and soil salinity control critically important for successful yam production in Saemangeum Reclaimed Tidal Land.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.112-119
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• 1994

The experiment was conducted to investigate the cause of the continous increase of Sagittaria trifolia dominance and it's effective control methods in the paddy rice fields. Early physilogical response of S. trifolia caused by sulfonylurea three herbicides resulted in growth cessation. However, the growth-ceased plant regrew after the certain period of time. Pyrazolate{4-[2, 4-dichloro benzoyl]-1, 3-dimethylpyrazol-5-yl-ptoluene sulphonate} could control S. trifolia until 6-7 leaf stages. The herbicidal activity of S. trifolia by pyrazolate was not related to the size of tuber and the amount of carbohydrate consumption in the tuber. The production of S. trifolia tubers inhibited more than 95% by the systematic treatment of pyrazosulfuron-ethyl{Ethyl-5-(4, 6-dimethoxy pyrimidin-2-yl carbomoyl sulfamoyl)-2-chloro-2', 6'-diethyl acetanilide}, cinosulfuron and pyrazolate after the first treatment of pyrazosulfuron-ethyl and pyrazolate.