• Weed & Turfgrass Science
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• v.6 no.3
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• pp.179-188
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• 2017

In order to provide basic data for efficient control of weedy rice, we analyzed emergence rate of 100 weedy rice genetic resources collected in South Korea according to growth temperature and soil burial depth. Analyzing of emergence rate using low dormancy weedy rice genetic resources, emergence was increased at 12 and $14^{\circ}C$ of mean temperature condition. When calculating the effective accumulated temperature above $10^{\circ}C$, emergence rate increased 0.6% and 0.5% in 1 cm and 3 cm of soil depth, respectively according to increase of $1^{\circ}C$. However it reduced as 0.28% in 5 cm of soil depth condition. Analyzing of emergence rate using high dormancy weedy rice, red rice showed 55%, 46%, 41% of emergence rate in 1 cm, 3 cm and 5 cm of soil depth condition, respectively. However those of white rice decreased as 10%, 8% and 5.7% in 1 cm, 3 cm and 5 cm of soil depth condition, respectively. Relative emergence, assuming the final emergence rate as 100%, reached 80%, 90% and 100% when effective accumulated temperature was $83-112^{\circ}C$, $100-123^{\circ}C$, $148-160^{\circ}C$ respectively.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.123-126
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• 1999

Effects of garlic juice (GJ), ethanol- (GJAE) and ethyl ether extract of garlic juice (GJEE), onion juice (OJ) and ethanol extract of onion juice (OJAE), garlic juice+Merit Blue (GJ+MB), ethanol extract of garlic juice+Merit Blue (GJAE+MB), onion juice+Merit Blue (OJ+MB), ethanol extract of onion juice+Merit Blue (OJAE+MB), and Merit Blue (MB) on budbreak, flowering, and maturity of plastic house-grown 'Daebong' grapes (Vitis labruscana B.) were studied. MB alone and in combination with other formulae hastened the budbreak, and double application was more effective than single one. Most of the buds sprouted in early forcing, but percent budbreak in late forcing was very poor except for MB application. In early forcing, single application of MB in combination with other formulae was most effective for hastening flowering while the response to double application was not consistent, and even delayed the flowering except for OJAE, MB, and OJ+MB. In late forcing, single application of all dormancy-breaking agents, especially MB in combination with other formulae, hastened the flowering while flowering response to double application was inconsistent, and even delayed the flowering except for OJAE+MB and OJ. Although there were no significant differences in harvest date among treatments and the number of application in early forcing, single and double application of MB alone and in combination with other formulae, especially double application of OJAE+MB hastened the harvest date for 12 days in late forcing culture.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.3
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• pp.124-131
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• 2012

This study was carried out to evaluate a possible change in freeze risk for 'Changhowon Hwangdo' peach buds in three major peach growing areas under the future climate projected by RCP8.5 emission scenario. Mean values of the monthly temperature data for the present decade (2000s) and the future decades (2020s, 2050s, 2080s) were extracted for farm lands in Icheon, Chungju, and Yeongcheon-Gyeongsan region at 1km resolution and 30 sets of daily temperature data were generated randomly by a stochastic process for each decade. The daily data were used to calculate a thermal time-based dormancy depth index which is closely related to the cold tolerance of peach buds. Combined with daily minimum temperature, dormancy depth can be used to estimate the potential risk of freezing damage on peach buds. When the freeze risk was calculated daily for the winter period (from 1 November to 15 March) in the present decade, Icheon and Chungju regions had high values across the whole period, but Yeongcheon-Gyeongsan regions had low values from mid-December to the end of January. In the future decades, the frequency of freezing damage would be reduced in all 3 regions and the reduction rate could be as high as 75 to 90% by 2080's. However, the severe class risk (over 80% damage) will not disappear in the future and most occurrences will be limited to December to early January according to the calculation. This phenomenon might be explained by shortened cold hardiness period caused by winter warming as well as sudden cold waves resulting from the higher inter-annual climate variability projected by the RCP8.5 scenario.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.7-13
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• 1989

The present study was carried out to get the basic information for clarifying physiological mechanism of breaking dormancy and sprouting in Panax ginseng roots. Changes in Abscisic acid (ABA) content and Gibberellin (GA) activity were investigated in one-year-old root during stratification at 4$^{\circ}C$. 15$^{\circ}C$. and 15$^{\circ}C$ after 60day-treatment at 4$^{\circ}C$. Sprouting rate at 15$^{\circ}C$ was 35％ in 30days storage at 4$^{\circ}C$ and 100％ in longer than 60days, but there was no sprout in both the constant treatment at 4$^{\circ}C$ or 15$^{\circ}C$ regardless of the treatment period. The longer the period of low temperature treatment. number of days to the first and 50％ sprouting was shortened, and number of days to 50％ from first sprouting was also shortened. ABA content in the upper part of root(contained bud) was gradually increased at both 4$^{\circ}C$ and 15$^{\circ}C$ as the treatment period was extended. and the degree of increase was higher at 15$^{\circ}C$. In the lower part. it showed a slight increase at 15$^{\circ}C$. while showed little change at 4$^{\circ}C$ throughout the treatment period. In the 15$^{\circ}C$ treatment after 60days at 4$^{\circ}C$, it was greatly increased in the upper part. while rather slightly decreased in the lower part of root. GA activity in the upper part was gradually decreased at both 4$^{\circ}C$ and 15$^{\circ}C$, and the degree of decrease was higher at 15$^{\circ}C$. In the lower part. it was similar tendency to those in the upper part. In the 15$^{\circ}C$ treatment after 60days at 4$^{\circ}C$. it was remarkably increased in both the upper and lower part. The increase was great in the low Rf region, while the decrease appeared relatively in the high Rf region compared to those of 60day-treatment at 4$^{\circ}C$. The above results indicated that the breaking dormancy and sprouting of bud were closely associated with the degree of GA activities in response to temperature condition .during stratification rather than the direct effect associated with the changes in ABA content.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.157-164
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• 2023

Codonopsis lanceolata (S. et Z.) Trautv. is mainly cultivated in Korea and China as a medicinal crop. C. lanceolata is difficult to produce plug seedlings in the summer, because C. lanceolata has a low germination rate and is vulnerable to high temperatures. Cold treatment is effective in breaking dormancy of seeds and increasing the germination rate. Shading cultivation can control the solar irradiance received by plants and reduce the damage by high temperatures and strong light. This study was conducted to examine the appropriate cold treatment period for the improving germination of C. lanceolata, and shading level during the summer seedling period. Cold treatment experiments were conducted for 0 (control), 1, 2, 3, and 4 weeks at 4℃ before sowing. In the shading experiment, C. lanceolata was grown for 45 days with 0 (non-treatment), 45, 75% shading levels. Cold treatment for one week significantly improved the germination energy. The plant height, leaf area, and fresh and dry weights of C. lanceolata seedlings were significantly increased under the 45% shading level. Total root length, root surface area, and the number of root tips were significantly higher in shading treatment (45 and 75%) than in non-treatment. The C. lanceolata seedling's compactness and Dickson's quality index were the highest at 45% shading level. Therefore, these results recommended sowing C. lanceolata after cold treatment for one week at 4℃, and 45% shading level could stably culture C. lanceolata plug seedlings during the high temperature period.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.47-68
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• 1988

This study was conducted to define the optimal conditions for embryo growth during seed stratification and for breaking dormancy as well as seed germination of stratified ginseng seeds. The experiments were also carried out to detect some materials which were expected to induce seed dormancy in the ginseng seeds. The results summarized as follows; 1. The growth of embryo during seed stratification was significantly inhibited by the existence of endocarp. The fastest embryo growth was resulted at $15^{\circ}C$ and an estimated optimal temperature for embryo growth was about $18^{\circ}C$. 2. There was no significant difference between the embryo growth and germination ratio of ginseng seeds which were sown in seed bed at Aug-5 without seed stratification and that of artificial seed stratification. 3. Embryo growth and germination ratio was significantly inhibited by high temperature treatment at $30^{\circ}C$ for 24 hours or respiration stress by immersing seeds in water for 10 days or more. 4. When the seed stratification was started at $10^{\circ}C$, growth of embryo in the ginseng seeds were almost stopped. But, when the seeds were stratified first at $20^{\circ}C$ for 50 days and next at $10^{\circ}C$ for 50 days, the embryo growth was significantly promoted compared with the embryo growth in the seeds which were stratified at $20^{\circ}C$ for 100 days. 5. The successive embryo growth after seed stratification was significantly accelerated at $10^{\circ}C$ but the seeds chilled at $5^{\circ}C$ for 100 days were resulted in the highest germination ratio as well as the shortest days for germination. 6. The successive embryo growth during chilling treatment and seed germination were significantly inhibited by immersing seeds in water just before chilling treatment or during chilling treatment and by interruption of chilling treatment with raising temperature to $20^{\circ}C$ for 20 days during chilling treatment. 7. The germination ratio of ginseng seeds which finished chilling treatment was highest at $10^{\circ}C$ and 62.5% was the estimated soil moisture for the best germination of ginseng seeds. The ginseng seeds were found to require high amount of oxygen for germination. 8. Only water soluble material in homogenized ginseng seeds showed a significant inhibiting effect on the seed germination of sesame, millet and soybean. Water soluble material dissolved from undehisced ginseng seeds showed stronger inhibiting effect on the seedling growth of sesame than material from dehisced ginseng seeds. Extraction temperature did not influence the inhibiting effect of the material dissolved from ginseng seeds on the seedling growth of sesame. 9. Water soluble materials dissolved from the berry pulps, leaves, fresh roots and dried roots also showed a significant inhibiting effect on the seedling growth of sesame. 10. Water soluble materials dissolved from the ginseng seeds, leaves and fresh roots showed a significant inhibiting effect on the germination of true fungi and the growth of spawn but the growth of phytopathogenic bacteria was not. 11. Among the water soluble materials dissolved from ginseng seeds, the materials of low molecular weight less than 3,000 were resulted a significant inhibiting effect on the seedling growth of sesame and the materials of high molecular weight also showed an inhibiting effect.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.1-16
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• 2000

This study was carried out to examine the process of plant succession through vegetation invasion and to select appropriate endemic plant species for rapid stabilization and good visual effect on cut-slopes of forest roads. Establishing total of sixty $1m{\times}1m$ sample plots. fifteen for each forest road constructed in the year of '93 (six-year-old), '95(four-year-old), '97(two-year-old), and '98(one-year-old), the ecological attributes of invading vegetation on cut-slopes were analyzed. The results are summarized as follows: 1. The rate of vegetation coverage was highly associated with soil hardness and aspect of cut-slope. Higher rate of vegetation coverage was caused by larger number of invading plant species. 2. The dominant woody species were Rubus crataegifolius, Rhus chinensis, Lespedeza bicolor, Salix hulteni, Alnus hirsuta, and Pinus densiflora. The visual attractive for the fruit of Rubus crataegifolius and the autumn coloration of Rhus chinensis was noteworthy. The dominant herbaceous species were Youngia sonchifolia, Spodiopogon sibiricus, and Lysimachia clethroides in all study forest roads. Spring flower of Potentilla freyniana and Viola rossii: summer flower of Lysimachia clethroides, Commelina communis, Glycine soja. Persicaria sieboldi, and Oenothera odorata: and autumn flower of Artemisia stolonifera and Impatiens textori were abundant and remarkable. 3. The diversity index of woody species tended to be increased as years passed after construction, and that of herbaceous species were decreased. 4. The dominance of Th of dormancy form was early high in the first year of construction, getting decreased thereafter. And that of MM + M + N was increased as years passed after construction. but that of Ch+H+G+Th+HH was decreased. 5. The degrees of succession were estimated by 359, 111, 97, and 87 for the construction year of '93, '95, '97, and '98. respectively, increased as years passed after construction.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.162-169
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• 2016

The agrometeorological reference index means 'the agrometeorological damage possibility' or the possibility of the normal year climate condition to damage the crop cultivation in a certain region. It is a reference used to compare the cultivation risk of a crop by region. The global climate warming is expected to increase the winter temperature. At the same time, the frequency of extreme weather events will also increase. Therefore, people pay attention to the potential of low temperature-induced damages (e.g., frost damage and injury) to fruit trees under the future climate condition. However, simple damage projection based on climate conditions does not help the climate change adaptation in the practical aspect because the climate change affects the phenology of fruit trees as well. This study predicted the phenology of the pear, peach, and apple trees by using the climate change scenarios of major regions. Furthermore, low temperature induced agrometeorological reference indices were calculated based on the effects of temperature on each plant growth stage to predict the damage possibility. It was predicted that the breaking rest would delay more in the future while the bud-burst date and flowering date will be earlier. In Daegu, Jeonju, and Mokpo, the breaking rest delayed more as time passed. The bud-burst date and flowering date of Seoul and Incheon regions were later than other regions. Seoul and Incheon showed a similar pattern, while Daegu and Jeonju revealed a similar pattern. Busan and Mokpo also showed a similar pattern. All regions were safe from the frost damage during the dormancy period. However, plants were vulnerable to frost damage between the breaking rest and the bud-burst period. Regions showed different frost damage patterns between the bud-burst period and the flowering period. During the bud-burst and flowering period, the risk level decreased in general, although the risk of some areas tended to increase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.388-393
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• 2015

Buckwheat sprouts are a vegetable; a functional food should provide health benefit and enhance performance as high nutritionally important substances. Buckwheat noodles are the major buckwheat food in Japan, Korea and China. In addition, Buckwheat as preventive medicine has undergone a great advancement in the last decade. Comparison of the functional properties distribution and utilization in tatary buckwheat is required of understanding the metabolites. The study was conducted to identify the sorts of phenolic compounds and metabolites in tatary buckwheat seedling at 4, 7, and 10 days seedling under the different combinations of light-emitting diode (LED) such as blue, red, mix (red, blue, and white), dark, and natural lights in stem and leaves. After breaking the dormancy, buckwheat seeds were grown in culture room under lights for 14 hrs and the dark condition for 10 hrs, at $25^{\circ}C$ for 10 days. Length of buckwheat was gradually increased under all of the conditions. Using HPLC, rutin was highest at 7 days under mix and natural light in stem and leaf, respectively. Quercetin was highest at 4 and 7 days under natural light in both. Chlorogenic acid was highest at 7 days under mix and natural in stem and leaf, respectively. Taken Together, this study indicates that phenolic compounds and metabolites present in those plants could be helpful for the human health and nutritional additive.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.308-319
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• 2016

The purpose of this study is to identify distribution patterns of hydrophytes in the Mokpo wetland in relation to the depth of water. Sample surveys were conducted based on plant species distribution status and water depths at 274 spots. This study also developed a detailed depth distribution map for Mokpo wetland, which was never done in any previous studies. Through this study, it was found that the average depth of the wetland was 77cm (${\pm}29cm$) and the maximal depth was 157cm. The outer edge was no deeper than 60cm and the center approximately 120~130cm in depth, forming a concave bowl-like shape. This research confirmed inhabitation of 6 types of submerged plants (Verticillate hydrilla, Vallisneria natans, Najas graminea, Potamogeton cripus, Ceratophyllum demersum, and Potamogeton brechtoldi), and three types of floating leaved plants (Euryale ferox, Hydrocharis dubia and Trapa japonica) in the surveyed areas of the wetland. The distribution of these hydrophytes showed a statistically significant difference (${\chi}^2=982.2$, df = 8, p < 0.01), which confirms the fact that distribution varies based on environmental conditions. The most frequently observed species was Trapa japonicas at 244 times, and it showed a distribution pattern by which coverage increased with greater depth, as was also seen in the case of Potamogeton cripus. Five species-Euryale ferox, Hydrocharis dubid, Verticillate hydrilla, Najas graminea, and Ceratophyllum demersum-showed a negative correlation to depth, by which coverage decreased with increasing depth. It has been shown that fundamentally, the distribution of hydrophytes based on depth is affected by ecological factors, but also reflects the environmental properties of Mokpo wetland.