• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.987-993
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• 2020

This study investigated the effective harvest of 'Kyoho' grapevines by examining their characteristics including bud development, necrosis types and flower primordium formation. The size of the axillary bud did not show any difference in the 5th node or more, but it was smaller because it was closer to the base in the 4th node or less. In the 1st node, the rates of main bud necrosis (MBN), accessory bud necrosis (ABN), and whole bud necrosis (WBN) were high, and the rate of flower primordium formation was low, but there was no significant difference in the other nodes. Therefore, it was expected that using other nodes than the 1st node would be advantageous to secure production. Because the growth progresses after sprouting, the main bud necrosis rate increases, showing a very low flower primordium formation rate in March of the following year. Therefore, a method is needed to increase the storage nutrients in the winter and the rate of flower primordium formation after March. This study found that the thickness of the shoots should be less than 8.5 mm between the 3rd and 4th nodes, and the length should be less than 60 cm for nodes up to the 10th node.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.89-92
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• 2004

This work describes a model development and numerical simulation of detailed combustion mechanisms of RDX/GAP/BTIN propellants. The analysis is based on the conservation equations of mass, energy, and species concentrations for both the condensed and gas phases, and takes into account finite-rate chemical kinetics and variable thermophysical properties. The model has been applied to study the combustion wave structures and burning characteristics of RDX/GAP/BTIN propellants over a broad range of pressures. Reasonably good agreement is achieved between the calculated and measured burning rate at atmospheric pressure. But the model calculation does not result in dark zone experimentally observed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.312-312
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• 2017

The study was conducted to select optimal materials for promoting germination rate, high sprouting vigor by priming treatment using PEG 6000 (water potential -0.5 to 2.0 Mpa) and Azolla extracts (0.1, 1.0, and 10.0%) extracted by ethanol, distilled, and/or hot water in colored rice cultivars. Each rice seed (three black rice cultivars and two red rice cultivars) was soaked 24 and 48 hr including untreated control. In black rice, Joseongheugchal rice cultivar, azolla ethanol extract (0.1%) induced highest germination rate, germination speed was taken to 5 days in distilled water and to 3days in Azolla extracts extracted hot water. Otherwise, degree of bacterial inhibition (number of colony, $10^3cfu$) in dry seed, water soaking for 24hr, soaking with fungicide for 24hr and 48hr, soaking with fungicide and aeration for 24hr and 48 hr was 22, 500, 95, and 0.46, respectively. In order to minimize fungal inhibition, a method can be chosen to combination of soaking fungicide and aeration for 48 hr. In seed priming treatments using growth pouch, seed soaking with fungicide did not affect change of germination percentage and germination speed, it delayed only 2 or 4day in the Joseongheugchal rice cultivar. It differs from rice cultivars and priming materials, Azolla extract(0.1 to 1%) promotes seed germination percentage in the Ilpum, Hongjinju, and Joseonghuegchal, in addition, germination in Jeogjinju cultivar was only promoted by PEG solution(10 to 20%), otherwise, it showed much lower or inhibited on the germination in Heugjinju and Sinmyungheugchal rice cultivars. In a paddy field trial, seedling establishment rate by applying PEG6000 and azolla extract did not show significantly statistical difference. When it compared with untreated control, seedling establishment rate was increased over 50% in priming treatments. Interestingly, seedling establishment rate under azolla extract (0.1%) extracted with ethanol was promoted over 2.5 times compared to the control in a black rice, Joseongheugchal and red rice, Jeogjinju.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.186-194
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• 1994

Lack of seedling vigor is considered a serious deterrent to use of broadleafed birdsfoot trefoil (Lorus comicul~rus L.). Our objectives were to compare early seedling growth of broadleafed birdsfoot trefoil cultivar "MO-20" and the large-seeded accession 302921 at $15^{\circ}C$ and $25^{\circ}C$. in controlled-environment chambers. Cabon dioxide exchange rate (CER) was measured in a closed or open system using infrared gas analysis. Dark respiration rate was measured manometrically. Net carbon accumulated per day and growth analysis of the seedlings were calculated. Initial seed mass of 302921 was 3.5 times larger and final cotyledon area was 2 times larger than those of MO-20, and early seedling growth was better. But, from 3 weeks after emergence until the end of the test period at $25^{\circ}C$, MO-20 showed higher CER per unit leaf area and faster dry weight accumulation than did 302921. Compared with $25^{\circ}C$, growth of MO-20 at $15^{\circ}C$ was suppressed more than that of 302921. Dark respiration rate of MO-20 was slightly higher than that for 302921, but not COz uptake per day for MO-20 was highest at$25^{\circ}C$ and lowest at $25^{\circ}C$. The relative growth rate (RGR) of MO-20 was higher than 302921 at $25^{\circ}C$ due to high net assimilation rate, but there was little difference in RGR between entries at $15^{\circ}C$.}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.381-388
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• 2004

In Korea, production of super sweet corn has been economically feasible and is substituting for traditional sweet corn due to better flavor in recent years. Major limiting factors for super sweet corn production are low field emergence and low seedling vigor. The optimum water potential (WP) for the priming of normal and aged seeds of dent, sweet (su) and super sweet (sh2) corns was studied to improve low seed quality. Seeds were primed at 0, -0.3, -0.6, -0.9, and -1.2 MPa of polyethylene glycol (PEG) 8000 solution at $15^{\circ}C$ for 2 days. Priming effects differed depending on the type of corn, seed quality, and WP of PEG solution. Although WP of priming solution did not influence the emergence rate of extremely high quality normal dent corn seeds, it reduced time to $50\%$ emergence (T50) and increased plumule weight. In contrast, the emergence rate of aged field corn was improved by seed priming at 0 MPa and plumule weight and $\alpha-amylase$ activity was enhanced. The optimum WP for both normal and aged sweet and super sweet corn seeds was between -0.3 and -0.6 Mpa. At the optimum WP emergence rate, $\alpha-amylase$ activity, and content of DNA and soluble protein increased, while T50 and leakage of total sugars and electrolytes reduced.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.88-99
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• 2009

This study was conducted to formulate management guidelines for Natural monumental old trees in Korea through survey of tree vigor and analysis of growing environments. A total of 20 old trees designated as natural monuments in Seoul, Incheon, and Gyeonggi Province were surveyed. The biological characteristics were surveyed with 4 items of species, ages and height of trees. The surrounding environments were surveyed with 2 items of location types and surroundings. The root conditions were surveyed with 2 items of denudation and molding depth. The health conditions were surveyed with 5 items of withering rate, cavity size, bark breakaway rate, damages by blight and insects, and growing tips. The soil conditions were surveyed with 6 items of PH, organic contents, valid phosphoric acid, transposal cations(K, Ca) and soil compaction. On the basis of outcomes of these research items, mutual relations among locations, growings and soil conditions of old trees were analyzed by carring out cross tabulation, correlation, and simple and multiple regression. Management guidelines were presented searching the factors effecting on the health of the monumental old trees. On the biological characteristics, the old trees designated as natural monuments were Pinus bungeana(4 trees), Juniperus chinensis(3 trees), Ginkgo biloba(3 trees), Poncirus trifoliata(2 trees). Actinidia arguta, Wisteria floribunda, Thuja orientalis, Quercus mongolica, Sophora japonica, Fraxinus rhynchophylla, Zelkova serrata, and Pinus densiflora. The tree height ranged from 4.2 to 39.2m, and root collar rounds ranged from 1.01 to 15.2m. On the surrounding environments, The location types ; Gardens(4), historical sites(5), residental sections(3) open agricultural fields(3), mountain hills(3), and near ocean beaches(1) and stream site(1). The surroundings ; 75% denudation of roots, molded more than 10cm except 4 trees(25%). On the health conditions, 1)Withering rate ; Ginkgo biloba(20%) in Yongmoon temple, (5%) in Saki-ri, kanwha-gun, and others had no withering rate. 2) Cavity size ; all subject had $5{\sim}100cm^3$ of cavity. 3) Bark breakaway rate ; Pinus bungeana in Soosong-dong, in the shrine of Confucius, in Samchung-dong, especially high rate of cavity(5~50%) in Seoul area and in Saki-ri, Kangwha-gun were high 45% brakeaway rate. 4) Damages by blight and insects was slight due to managements. 5Growing tips ; In cases of Juniperus chinensis in Changdeok palace and SunnogDang, seoul, growing tips were 1/2, presumably cause by air pollution, and in cases of Fraxinus rhynchophylla in Paju city and Pinus densiflora in BacksaDorip-ri, Icheon city, growing tips were fine, presumably because there were no moldings. On the Soil conditions, Soil pH ranged from 5.2 to 8.3, organic matter contents from 12% to 56%, phosphorus contents from 104 to 618ppm, soil compaction ranged from 7 to 28mm( among them, Denudation was severe with 21~28mm soil compactions in cases of Pinus bungeana in Soosong -dong, Thuja orientalis in Samchung -dong, Ginkgo biloba in the shrine of Confucius and in Yongmoon temple.) Results of cross tabulation, correlation, and regression analysis showed that molding depth was the most serious factor to deteriorate the tree vigor and cambium conductivity. In addition, soil acidity, organic matter contents, disease and insect damages and cambial detachment were also related to the tree vigor. Additional research of these relationships will be needed to conduct more detailed studies. Based on the relationships between the tree vigor and growing environments, it is considered that old trees should be managed to give them more growing spaces and less abuses. Also, molded soils should be removed and further soil-molding around the tree collar should be prohibited. For the construction of systematic management and removal of harmful factors, appropriative management according to spices, persistent monitering of damaged cases and construction of management system through the accumulation of data on the relationships of soil conditions are required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.101-105
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• 2010

Sunflower (Sunking4505) and Rape (Sunmang) are oil-seeds containing high oleic acid, and these are used for the production materials of bio-diesel and applying for phytoremediation. The effect of cadmium on germination rate and the growth of the plants is evaluated. Object seeds were placed in Cd (0, 1.5, 4, 12, 30, 60, 100, 150, 300, 500 mg/L) solutions for seven days, and germination rate, root length, shoot length, seedling length, and dry weight were observed. $IC_{50}$, seedling vigor index, and tolerance indices were computed, and data were statistically analyzed by Analysis of Variance (ANOVA). Germination rate as well as root, shoot, and seedling length decreased as the cadmium concentration increased except dry weight. The $IC_{50}$ of sunflower and rape are 112 and 10 mg-Cd/L, respectively. Only one of the sunflower seeds is germinated at 500 mg-Cd/L whereas rape seeds are not germinated more than 150 mg-Cd/L solution. Root has higher cadmium sensitivity than shoot, and sunflower has higher germination rate, growth, and seedling vigor index than rape. In case of tolerance indices, sunflower has lower value than rape at relatively low concentration, but has higher value at high concentration.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.235-248
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• 2017

This study was initiated to investigate seed germinating vigor, germination speed, and establishment characteristics of Festuca species under natural conditions ($5-25^{\circ}C$). Germination rate was 62.0% in CRF 'Audubon' to 97.0% in TF 'Olympic Gold'. It was greater with TF over fine-type fescues, being TF>SF>CF, HF>CRF. The germination speed, measured as days to seed germination of 50% through 80%, was fastest with TF, medium to high with CF, medium with HF and SF, and slowest with CRF. However, it was approximately 4 days slower under natural conditions, as compared with that under alternative conditions ($15-25^{\circ}C$). Germination peak time was much faster with TF. It ranged from 0.73 to 1.84 days with TF, being 1.45 days in average. But it varied with 2.16 to 11.75 days among fine-type species. The peak time was longer in order of SFCF>SF>HF>CRF.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.299-306
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• 2010

The use of local seed provenance is often recommended in forest restoration. Early vigor is a combination of the performance of seed germination and emergence after planting. The ability of young Brant's oak plants to grow and develop after emergence and its dependence on local habitat conditions was investigated in this study. The effects of seed source and shade on early growing seedlings of Brant's oak (Quercus brantii L.) were determined in field measurements. Seeds of Quercus brantii L. were collected from 4 forest areas (seed sources) in southern Zagros (Provinces of Kohkilouyeh-Bouyer Ahmad and Fars) at altitudes of 850, 1,100, 1,500, 2,100 m a.s.l., and planted in a nursery constructed in southwestern Iran. According to a split-plot design consisting of four blocks, each containing two main treatment plots (no shading, partial shading), each main plot was sub-divided into four sub-plots (for elevations of 850, 1,100, 1,500 and 2,100 m). Results showed that shade treatments had significant effects on emergence percentage and rate, shoot length, shoot dry weight (SDW), root dry weight (RDW), leaf area (LA), and chlorophyll content. Ecological factors also had an effect on seed performance. Altitude of seed source had a very significant effect on root length, LA, SDW, and RDW. The seeds collected from 850 m a.s.l. elevation showed the highest performance, especially in leaf area, root length, shoot dry weight, and root dry weight. Our results showed that the altitude of 850 m a.s.l. was the best for collecting Brant's oak seeds.

• Journal of Embryo Transfer
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• v.23 no.2
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• pp.115-118
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• 2008

Glycerol is the cryoprotectant most frequently used to freeze semen in several of species. The objective of the present study was to compare the effect of three different glycerol concentrations (4, 6 or 8%, v/v) on frozen-thawed dog sperm survival rate. Ejaculates from 9 dogs collected by digital manipulation were pooled and assessed by macroscopic and microscopic criteria. Semen was divided into 3 aliquots, which were centrifuged and the sperm pellets rediluted with first Tris-glucose-citric acid extender. After 1 h cooling at $4^{\circ}C$, second extender containing 4, 6 or 8% glycerol was added, respectively. The semen was loaded into 0.25 ml straws and frozen and stored in liquid nitrogen and thawed. Sperm vigor, live:dead spermatozoa ratio using HOS test, and sperm morphology using $Spermac^{(R)}$ stain were evaluated. After thawing, there were no significant differences among groups in vigor, viability and morphology. In conclusion, the three glycerol concentrations (4, 6 or 8%) can be used successfully in cryopreservation of canine semen. Therefore the use of 4% glycerol in the extender has less toxic effect and reduces of freezing injuries.