• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.79-87
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• 2010

Research was initiated to investigate the early establishment characteristics and germination patterns of perennial ryegrass (PR, Lolium perenne L.). Eight cultivars of PR were evaluated in the study. Experiment was conducted under a room temperature condition of $6^{\circ}C$ to $23^{\circ}C$ (natural conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and germination percentage with different environments and cultivars. Germination percentage was variable with cultivars at the end of study. It was 66.25 to 93.50% under natural conditions. There were considerable variations in the early germination characteristics and germination pattern among the entries according to different conditions. The first germination was initiated between 3 and 5 DAS (days after seeding) under ISTA (International Seed Testing Association) conditions. But it started between 6 and 8 DAS under natural conditions, being 2 to 4 days later as compared with that under ISTA conditions. It was 8 to 12 DAS that reached to days to the 50% germination, which was 2 to 5 days after the first germination. Days to the 75% germination were 10.08 to 13.70 DAS under natural conditions, being 2.07 to 5.70 days slower as compared with ISTA conditions. 'Pennant II' was the fastest cultivar. But the slowest was 'Catalina II' that was 3.62 days later than 'Pennant II' under natural conditions. Considering days to the first germination, days to 75% germination, and germination pattern etc, 'Pennant II' and 'Brightstar II' were regarded as excellent cultivars under both conditions. From this study, information on differences in germination characteristics and patterns would be usefully applied for golf course design and construction, when established with PR.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.21-29
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• 1999

This study was carried out to determine the promising method for the production of mother bulbs using garlic bulbs at the experimental field of Ange high school, Eusung in Korea from 1996 to 1998. The bulbs and bulbils were taken from a local cultivar 'Eusung' garlic. The growth of bulbil and yield potential were compared with different harvesting times and cultivation methods of bulbil. The harvesting time of bulbils which were capable of producing the mother bulbs was ranged from 15 days to 30 days after the emergence of flower stalks. The best results based on the yield and number of bulbs were obtained from the bulbils sampled at the just before garlic harvesting, 30 days after flower-stalk emergence. The mulching with transparent polyethylene(PE) film in bulbil cultivation was more effective for the plant growth and bulb formation than that with black PE film. The PE mulching from 30 days after seeding of bulbils to 30 days (late-April) before bulb harvesting was the moot effective for the increase of bulb yield. In the cultivation of garlic bulbils, application of lime (150 kg/10a) and compost (3,000 kg/10a) without any chemical fertilizers produced more bulbs in comparison with the standard level of fertilizer (N - $P_2O_5$ - $K_2O$ - compost - lime = 24.8 - 8.0 - 19.2 - 3,000 - 150 kg/10a). It was determined that the involucre seeding and assemble seeding of bulbils was effective and labour-saving methods for the production of mother bulbs from garlic bulbils. Input of labour force for the involucre seeding was decreased up to 61% as compared with the conventional drill seeding of bulbils. Mean yield from the cultivation of bulbil-derived single cloves was remarkably increased up to 95% in comparison with that of the common cloves. The larger size of single clove produced more yields, and the optimum planting density of single clove was $20{\times}10cm$. The cloves differentiated directly from bulbil showed to have higher yield potential than that from common cloves.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.1-10
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• 2011

This study was conducted to investigate early germination characteristics and germination pattern of new cultivars of creeping bentgrass (CB, Agrostis pall/stris Huds.) under natural room temperature conditions and to analyze differences between alternative and natural conditions. Seven cultivars of CB were tested in the study. Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 85% germination, and germination rate among cultivars under different environments. The first germination in all entries was initiated between 4 and 5 days after seeding (DAS) under alternative conditions, while between 6 and 8 DAS under natural conditions, being 2 to 3 days later as compared with that of alternative conditions. As for the first germination percentage, it was generally 5 to 25% under alternative conditions. However, 'Penn A-1', 'Penncross', and 'Penn A-4' cultivars showed a vigorous germination, producing 50 to 70%. Under natural room temperature conditions, it was 5 to 10% for the most entries, except 'Penncross', 'L-93', and 'Penn A-4' cultivars which vigorously produced 20 to 50%. Days to the 50% germination in CB resulted in 4 to 10 DAS under alternative conditions, while 6 to 15 DAS under natural conditions, being 2 to 5 days later than under alternative conditions. Days to the 85% germination were 5.90 to 11.75 DAS under alternative conditions and 7.95 to 12.50 DAS under natural conditions. 'Penn A-1' and 'L-93' were the fastest cultivars under alternative and natural conditions, respectively. Regardless of the temperature conditions, the longest cultivar in germination was 'T-1', being over 11 DAS. In-depth comparative data on germination characteristics and germination patterns among CB cultivars would be usefully applied for a practical CB turf establishment in golf course construction etc.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.309-314
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• 2009

Incidence of rice stripe disease, caused by Rice stripe tenuivirus (RSV), was surveyed during 2002 to 2004. The incidence area and ratio of diseased fields were decreased gradually during those period. Rate of diseased plants were 45.8%, 45.0% and 43.7% in the susceptible cultivars Chucheong, Saechucheong and Ilpum, respectively. However, the rate was 4.4% in resistant cultivar Hwaseong. In addition, breakdown rate was also significantly high in the susceptible cultivars in Chucheong, Saechucheong and Ilpum showing 33.6, 33.2 and 31.9%, respectively. In Hwaseong, the breakdown rate was 0.8%. Collection efficiency was compared between two insect vector collection methods. Insect-sucking machine method was much more efficient than sweeping net method in collecting small brown plant hopper (SBPH). According to the survey of the population density of the insect vector during 2002 to 2004, the national average population density was gradually decreased year by year, 3.6, 2.3, and 1.3%, respectively. This result was significantly related with the decrease of the incidence of rice stripe disease. Control efficiency of rice stripe disease by treating several seedling box and water surface with insecticides against SBPH resulted that imidacloprid GR, Fipronil FG, Clothianidin+Probenazole GR and Thiamethoxam GR showed over 80% of control efficiency at 28 days after treatment at the early stage in nursery.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 1993.12a
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• pp.6-9
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• 1993

According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. Thus. to prevent these undesirable changes , val'ious techniques such as controlled atmosphere (CA) storage, modified atmosphere OIA) storage, including vacuum packaging have been receiving considerable attention, Although milch research has been done to find optimal conditions for whole intact frui ts and vegetables, only limi ted information is avai lable on fresh cut. and other minimally processed products. 81 iced frui ts exhibi t increas~d ethylene production and respiration compal'ed to whole f, 'uits during distribution in response to tissue damage. As a result, accelerated senescence and enzymatic browning OCCUI', Recent l'esearch on minimally processed fl'uits and vegetables has mainly focused on methods to inhibit browning, due to ban on use of sulfur dioxide, In order to retard or prevent these physiological changes, val'ious al ternatives, reducing agents. acidulants, chelating agents and inol'ganic sal ts have been evaluated for use on fresh cut fl'ui ts. Al though some agents were effective replacement for sulfur dioxide. consum$\textregistered$I'S demandless use of chemical on such products. Shel~ life of minimally processed products has been extended by inhibition of metabolic reactions associated with loss of quality and by inhibition of aerobic spoilage caused by wide variety of microorganisms. Appl ication of ~I.-\ packaging, including vacuum packaging, retards the rate of respiration, prevents growth of aerobic spoilage organisms, inhibits oxidation and color deterioration. Tissue softening is another major problem in minimally processed products because enzymes re 1 a ted to ce 11 wa 11 degrada t i on are not inactivated. Various treatments have been investigated for retardation of the softening of sliced products. Some studies have concentrated on the application of an active packaging system with ~I, l. packaging and calcium infi 1 tration as possible measures to retain firmness of processed products. In my opinion, one important step for production of minimally processed frui ts wi th favorabl e color of cut surface and firm texture is the selection of better cultivar. As the view, changing tendency of fresh color by apple cultivars and relationship between the tendency and PPO activity will be discussed in the seminar. In addition to the topic, research result on quality enhancement of fresh apple slices by heat shock treatment will be introduced.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.252-252
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• 2017

Nowadays water shortage is becoming one of the biggest problems in the Korea. Many different methods are developed for conservation of water. Soil water management has become the most indispensable factor for augmenting the crop productivity especially on soybean (Glycine max L.) because of their high susceptibility to both water stress and water logging at various growth stages. The farmers have been using irrigation techniques through manual control which farmers irrigate lands at regular intervals. Automatic irrigation systems are convenient, especially for those who need to travel. If automatic irrigation systems are installed and programmed properly, they can even save you money and help in water conservation. Automatic irrigation systems can be programmed to provide automatic irrigation to the plants which helps in saving money and water and to discharge more precise amounts of water in a targeted area, which promotes water conservation. The objective of this study was to determine the possible effect of automatic irrigation systems based on soil moisture on soybean growth. This experiment was conducted on an upland field with sandy loam soils in Department of Southern Area Crop, NICS, RDA. The study had three different irrigation methods; sprinkle irrigation (SI), surface drip irrigation (SDI) and fountain irrigation (FI). SI was installed at spacing of $7{\times}7m$ and $1.8m^3/hr$ as square for per irrigation plot, a lateral pipe of SDI was laid down to 1.2 m row spacing with $2.3L\;h^{-1}$ discharge rate, the distance between laterals was 20 cm spacing between drippers and FI was laid down in 3m interval as square for per irrigation plot. Soybean (Daewon) cultivar was sown in the June $20^{th}$, 2016, planted in 2 rows of apart in 1.2 m wide rows and distance between hills was 20 cm. All agronomic practices were done as the recommended cultivation. This automatic irrigation system had valves to turn irrigation on/off easily by automated controller, solenoids and moisture sensor which were set the reference level as available soil moisture levels of 30% at 10cm depth. The efficiency of applied irrigation was obtained by dividing the total water stored in the effective root zone to the applied irrigation water. Results showed that seasonal applied irrigation water amounts were $60.4ton\;10a^{-1}$ (SI), $47.3ton\;10a^{-1}$ (SDI) and $92.6 ton\;10a^{-1}$ (FI), respectively. The most significant advantage of SDI system was that water was supplied near the root zone of plants drip by drip. This system saved a large quantity of water by 27.5% and 95.6% compared to SI, FI system. The average soybean yield was significantly affected by different irrigation methods. The soybean yield by different irrigation methods were $309.7kg\;10a^{-1}$ from SDI $282.2kg\;10a^{-1}$ from SI, $289.4kg\;10a^{-1}$ from FI, and $206.3kg\;10a^{-1}$ from control, respectively. SDI resulted in increase of soybean yield by 50.1%, 7.0% 9.8% compared to non-irrigation (control), FI and SI, respectively. Therefore, the automatic irrigation system supplied water only when the soil moisture in the soil went below the reference. Due to the direct transfer of water to the roots water conservation took place and also helped to maintain the moisture to soil ratio at the root zone constant. Thus the system is efficient and compatible to changing environment. The automatic irrigation system provides with several benefits and can operate with less manpower. In conclusion, improving automatic irrigation system can contribute greatly to reducing production costs of crops and making the industry more competitive and sustainable.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.427-433
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• 2014

Trellising is an important cultural practice that affects grape quality and yield. Some grape cultivars require different trellising under different climate and soil conditions. To find suitable trellis conditions for grape cultivar 'Cheongsoo', we measured growth and fruit characteristics with three different trellis systems: curtain, Geneva double curtain (GDC), and modified T. The maximum light exposure of clusters in the curtain, GDC, modified T trellis systems was 670, 1,654, and $1,649{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. However, there was no difference in air temperature among the three trellis systems. Net $CO_2$ assimilation rate at $1,500{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity was 13.4, 13.7, and $8.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in curtain, GDC, and modified T trellis systems, respectively. Trunk cross section area (TCSA) and bud burst rate were not significantly different among the three systems. Shoot number was 31.3, 47.0, and 37.0 in curtain, GDC, and modified T trellis systems, respectively. The shoot length was higher (243.9 cm) in the modified T trellis system than in the single curtain (171.1 cm) and GDC (151.5 cm) systems. Interior leaf number and leaf layer number were higher in the GDC system, in which there are two primary branches, in comparison to the modified T and curtain systems, which utilize one primary branch. Primary leaf area and lateral leaf area were significantly higher in the modified T trellis system in comparison to the GDC system. Berry weight, length and diameter, and total soluble solids were not significantly different among the three trellis systems. However, cluster weight and cluster number per tree were significantly higher in GDC. Titratable acidity was significantly lower in GDC. Collectively, our data suggest that the GDC trellis system is preferable for grape 'Cheongsoo' to maintain fruit quality and quantity in Korea.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.246-254
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• 2013

Five isolates of Tomato yellow leaf curl virus (TYLCV) collected from various regions of Korea were amplified using PCR and determined the sequences of full-length genome, respectively. The PCR-amplified DNA of each TYLCV isolate was introduced into a binary vector to construct infectious clone containing 1.9 copies of the corresponding viral genome. Various cultivars and breeding lines of tomato were inoculated with Agrobacterium tumefaciens harboring infectious clone of each TYLCV isolate to assess resistance against TYLCV. Susceptible cultivar 'Super-sunread' revealed typical yellowing and narrowing of the upper leaves. In contrast, breeding linesTY12, GC9, GC171, and GC173, which contained the TY-1 and/or TY-3 genes that confer resistance against TYLCV in nature, were completely symptomless, suggesting that the lines were resistant to challenging TYLCV isolates. Symptoms of TYLCV in susceptible tomato cultivars are significantly different from those of TYLCV in the resistant tomato cultivars at 30 days after agroinfiltration. Although genomic DNAs of TYLCV were detected from the breeding lines TY12, GC9, GC171, and GC173 using real-time PCR analysis with specific primers, levels of TYLCV DNA accumulation in the resistant breeding lines were much lower than those of TYLCV DNA accumulation in susceptible tomato cultivars. Similar symptom severity and levels of TYLCV DNA accumulation were observed from TYLCV infections mediated by Bemisia tabaci in the resistant and susceptible tomato cultivars. Concentration of agrobacterium did not affect the response of tomato cultivars against TYLCV inoculation. Taken together, these results suggest that TYLCV inoculation via agroinfiltration is as effective as inoculation through Bemisia tabaci and is useful for breeding programs of TYLCV-resistant tomato.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.271-279
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• 2012

Total twenty cultivars of potato (Solanum tuberosum L.) were grown at Gangneung where is located in low land of Korea. Their tubers were harvested from 100 to 120 days after planting, and over 150 g of tubers were selected for quality evaluation. Dry matter, starch, amylose in starch, ascorbic acid, protein, individual sugars and mineral were analyzed and mealiness of cooked potatoes were also evaluated by panel test. Dry mater content was the highest in 'Haryeong', 'Jayoung' and 'Shepody', and the biggest starch granules were observed in 'Jayoung' and 'Sinnamjak'. In addition, the content of amylose was highest in 'Haryeong', 'Chudong' and 'Goun'. Mineral content showed the slight difference between cultivars, but it's tendency was not clear. Vitamin C content was highest in 'Jayoung' as 62.5 $mg{\cdot}100g^{-1}$ FW, and 'Chugang' exhibited the highest content of protein. Sugar content was lower in cultivars for single one than double cropping. The lowest sugar content was observed in 'Atlantic' and 'Namseo' among cultivars for single cropping, and in 'Goun' for double cropping. As a result of analysis for quality factors, we could select nine cultivars ('Atlantic', 'Gahwang', 'Gawon', 'Goun', 'Hareong', 'Irish Cobbler', 'Jasim', 'Jayoung' and 'Shepody') with high dry matter content and low reducing sugar as a cultivar group for processing. Additionally, seven cultivars ('Chugang', 'Gawon', 'Goun', 'Hareong', 'Irish Cobbler', 'Jasim' and 'Seohong') with high mealiness and amylose content and five cultivars ('Atlantic', 'Chudong', 'Gahwang', 'Jopung' and 'Jowon') with low mealiness and amylose content were classified as groups for boiled or steam cooking and for soup or pot dishes, respectively.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.767-776
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• 2016

The aim of this study was to evaluate key properties of the prickly pear cactus (Opuntia ficus-indica var. saboten (OFI) ie, levels of key chemicals (carotenoids, flavonoids and polyphenolic compounds as well as phenolic acid) and its antioxidative potential, depending on where the plant had been cultivated in Korea. The levels of flavonoids and polyphenolic compounds in OFI were 55.45~65.32 mg (+)-catechin/g and 149.00~181.15 mg gallic acid/g, respectively. Protocatechuic acid was the most abundant phenolic acid in the ON1 and ON2 (161.90 and $196.25{\mu}g/g$ DW (dry weight)). Nineteen flavonoids were identified and analyzed by LC-ESI-MS in cladodes from OFI. Narcissin was the most abundant flavonoid in all of the samples ($1,241.89{\sim}1,775.10{\mu}g/g$ DW). Capxanthin and zeaxanthin were the most abundant carotenoids in OFI (64.88~128.08 and $48.10{\sim}93.82{\mu}g/g$ DW). The level of DPPH radical and ABTS radical scavenging activities in OFI were 10.78~25.35 and 16.85~34.16 mg AA eq/100 g, respectively. OFI by cultivar has different kind of phenolic acid, flavonoids, and carotenoids. Therefore, dietary intake of cladodes from OFI may be helpful for improving human health.