• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.314-320
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• 2014

The uptake and transportation patterns of the residual boscalid and chlorfenapyr were investigated from the soils to Korean cabbages. The recovery rates of the pesticides spiked in the soils and Korean cabbages were 87.5 to 105.2%. Korean cabbages were cultivated in soils treated with two different concentrations of the pesticides as low (3.0 mg/kg) and high (6.0 mg/kg) concentrations in greenhouse for 28 days. The initial level of boscalid was determined as 2.77 and 5.66 mg/kg for the low and high concentration of boscalid-treated soils, respectively. After 28 days of treatment, the residual boscalid in soils decreased to 0.53 and 1.60 mg/kg for the low and high concentration of boscalid-treated soils, respectively, and thus it was reduced to 71.7 to 81.9%. The initial level of chlorfenapyr was determined as 2.38 and 6.43 mg/kg for the low and high concentration of chlorfenapyr-treated soils, respectively. After 28 days of treatment, the residual chlorfenapyr in soils decreased to 1.36 and 2.91 mg/kg for the low and high concentration-treated soils, respectively, and thus it was reduced to 42.9 to 54.8%. The residual pesticide analysis was done with 2 day intervals from 21 days-cultivated Korean cabbages after seeding. Uptake rates of boscalid from the soil to Korean cabbages were 2.4 and 2.2% for the low- and high-concentration of boscalid-treated soil, respectively. However, the uptake rate of chlorfenapyr by the cabbages was 1.5 and 1.3% for the low and high concentration-treated soil, respectively. The uptake rate of chlorfenapyr by the cabbages was lower than that of boscalid. These results showed that the residual pesticides in soil could be absorbed by Korean cabbages depending on their physicochemical properties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.125-130
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• 2005

This study was conducted from March 16 to July 6 in 2004 at Jeju Island to investigate the influences of sowing dates(on March 16, March 26, April 5, April 15 and April 25) on creeping bentgrass vegetation. The result obtained were summarized as follows; Plant height was 22.7 cm at March 16 planting. It was longest but after that planting, plant height gradually shorted. Then it was shortest at April 25 planting(16.6 cm). Root length and Minolta SPAD-502 chlorophyll reading value were directly proportional plant height response. Leave and root weight were greatest at March 16 planting. It were 1,373 kg /10a and 2,374 kg /10a, respectively. These weight decreased gradually as planting was delayed from March 16 to April 25. Degree land cover and density of creeping bentgrass were $98.0\%$ and $99.3\%$, respectively, at March 16. After that planting they were decreased ($97.5\%$, $98.7\%$). But degree land cover and density of weed tended to increased gradually as the planting was delayed. The number of weed species were increased from March 16 to April 25. It showed increase that Poa annua, Stellaria media and Chenopodium album var. centrorubrum(at March 16 planting), Poa annua, Digitaria adscendens and Chenopodium album var. centrorubrum(at March 26 planting), Digitaria adscendens, Chenepodium album var. centrorubrum and Stellaria media(at April 5 planting), Digitaria adscendens, Stellaria media and Chenopodium album var. centrorubrum(at April 15 planting), Digitaria adscendens, Polygonum hydropiper, Chenopodium album var. centrorubrum(at April 25 planting). Based on the these findings, optimum sowing date for growth of creeping bentgrass seems to be about early seeding in atmospheric phenomena and volcanic ash soils of Jeju island.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.23-30
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• 2003

This pot experiment was conducted to find out the effects of slaked lime($L_{0}$ ; 0.00, $L_1$; 3.75, $L_2$; 7.50, $L_3$; 11.25ｇ/pot) and silicate fertilizers($S_1$; 3.75, $S_2$; 7.50, $S_3$; 11.25ｇ/pot) on the seedling growth and yield of grass/clover mired swards on newly reclaimed hilly soil, and it's differences between both the soil improvers. The results obtained are summarized as fellows: Comparing with the $L_{0}$ treatment without soil improver, the seedling vigour and yields of both forages were markedly enhanced by the application of soil improver. The positive offsets of soil improvers tended to be relative higher on ladino clover than orchardgrass in mixed swards. The seeding vigour, botanical composition, and yield of ladino clover were more markedly influenced by the application of silicate fertilizer than slaked line. The yields of ladino clover were increased 75.8% by the 51 over $L_1$, and 32.0% by the $S_2$ over $L_2$, respectively.

• 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.

• 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 Journal of Natural Sciences
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• v.5 no.2
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• pp.49-62
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• 1992

This study was carried out to investigate the emergence, growth and yield components in rice inassoccation with Several cultivation methods direct sowing flooded paddy field(DSF), direct sowing by airplane(DSA), direct sowing in dry paddy field(DSD), 8days seedling planting(8DS), and 35days seedlingplanting(35DS). Also this study was attempeted to know the effects of calcium peroxide on germinationand early growth of rice under different soil conditions, seeding depth, application of organic matter,indirect sowing flooded paddy field.1. Rate of emergence was 73% in DSF, 70% in DSA, 62% in DSD, respectively, under the different cultivation method of rice in reclaimed paddy field.2. Degree of lodging in relation to cultivation was 5 at both DSF and DSA, 3 at DSD, 2 at both 8DS and 35DS respectively.3. Maximum tiller number was 568 per m2 at DSF and 527 at DSA. Heating was delayed for 4 days at DSF, 8 days at DSD and 2 days at 8DS as comparison with that at 35DS.4. Yield was higher 1% to 3% at DSF than that at DSA and DSD while decreased by 12% as compared with that of seedling planting.5. Total dry weight of seedling was decreased by 57% at 8DS, 60% at DSF 63% at DSD, respectively, under 0.3% of salinity. Ratio of decreasing in dry weight was higher with high salinity.6. The amount of O2 released was recorded highest to 2 to 3days after irrigatition, thereafter remaining constant to 10 days after irrigatition.7. The optimum coating amount of calcium peroxide for germination was a half of rice seed weight with 1 cm sowing depth and one-fold with 2-cm sowing depth when rice straw was not applied. With rice straw applied, on the other hand, the amount of peroxide was one-fold with 1-cm sowing depth. It was found that, under the condition of applied 600kg/10a, of 2-cm soil depth with rice straw calcium peroxide coating had no effect on emergence of rice seedling.8. In reclaimed paddy field, lodging degree was 7 with direct sowing by machine and 9 with direct sowing by hand.9. Yield was increased by 5% by applying rice straw with direct sowing by machine.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.67-76
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• 2017

The study was initiated to evaluate the effects of overseeding warm-season grass (Zoysia japonica Steud.) with cool-season grasses (CSG) on turfgrass density, uniformity and tiller appearance and to determine turfgrass species and seeding rate applicable for a practical use. Treatments were comprised of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), tall fescue (TF, Festuca arundinacea Schreb.) and their mixtures. Overall turfgrass density and uniformity were much better with the overseeded treatments over the control. In early stage after overseeding, the greater the PR in treatments, the greater the turfgrass density and uniformity. But the higher the KB, the lower the density and uniformity. From the middle-stage evaluation, however, we observed the opposite results as compared with early-stage findings. Accordingly, the KB was highest in turfgrass density and uniformity, while the PR lowest. In regards of mixtures, both turfgrass density and uniformity were better with increased KB and decreased PR in overseeding rates. As for a medium-quality mixtures of Korean lawngrass with CSG, it would be the best choice to apply with KB at $50g\;m^{-2}$ and equal combination of KB, PR and TF by 1/3 in mixing at $75g\;m^{-2}$ in terms of sustainable density and uniformity.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.333-344
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• 2017

This study was conducted to examine the effect of cool-season grass overseeding on the green period, turf quality and density in zoysiagrass lawn. Treatments were perennial ryegrass (PR) overseeding ($60g\;m^{-2}$) on medium-leaf type zoysiagrass, Kentucky bluegrass (KB) overseeding ($20g\;m^{-2}$) on medium-leaf type zoysiagrass and narrow-leaf type zoysiagrass, and no overseeding on medium-leaf type zoysiagrass. Overseeding of KB or PR effectively provided quality improvement of zoysiagrass lawn by extending green-period about one month in spring and two months in fall season. PR overseeding showed quick green cover within 2-3 weeks but decreased the quality of overseeded zoysiagrass lawn during the summer season. Whereas, KB overseeding showed slow green cover taking two to three month after seeding but provided stable and good turf quality throughout the years. KB or PR overseeding significantly increased the turf density of zoysiagrass lawn except the period of summer depression of PR. The ground coverage of cool-season grasses ranged from 30 to 80% with considerable seasonal variation. As a result, KB and PR have their strengths and weaknesses as an overseeding material. Thus, the use of KB and PR as a mixture would provide better overseeding performance in zoysiagrass lawn.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.450-454
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• 1988

This study was conducted to increase the quality of Astrragali radix and to decide the application amounts of N, P and K fertilizer for Astragalus membranaceus Bunge. The ferlilizers effect on the ash contents and extracts from the root and the dried root yield was studied. With increasing the application amount of nitrogen more than 5kg/10a, the acid insoluble ash content of root increased, but the ethyl alcohol and diethyl ether extracts decreased. No effect of phosphorus amount on the ash and extracts contents in root was observed. With increasing amount more than 7kg/10a, only the acid insoluble ash contents increased. The dried root yield increased with the application level until 5kg/10a of nitrogen, but the effects ot phosphorus and potassium application were not observed. Positive correlation was obtained significantly between the ash ($r=0.746^*$) and acid insoluble ash ($r=0.858^{**}$) contents and the potassium application amount, and the negative correlation was also obtained significantly between the extract contents and the nitrogen ($r=-0.778^*$ ; $C_2H_5OH$, $r=-0.848^{**}$ ; $(C_2H_5O)_2O$) and potassium ($r=-0.772^*$ ; $(C_2H_5O)_2O)$ application amounts. As the results in the first year from the seeding, it is recommended for quality of Astragali radix to apply 5, 7-14, 7kg/10a of N, $P_2O_5$ and $K_2O$, respectively.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.457-471
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• 2014

This study aims to present an evaluation scheme to improve the problems in tree shapes and tree growth which were identified through shape and growth assessments of landscape trees currently planted in Haedoji Park, Songdo, Incheon Metropolitan City after plant structure status and propriety review for funtion of space and concept of planting. Suitability the planting concept was evaluated according to function of space. The result indicated that the shade planting areas accounted for 29.5% of the the shade spaces area. 58.7%, respectively planting areas of visual landscape. And 11.8%, respectively planting areas of buffer. Because the planting areas was lacked according to the park established spatial configuration of central facilities and the result of plant young trees. Plant structure status required consideration with plant structure, density, size, growth status for improve planting function. The tree assessment was performed on a total of 28 species and 600 trees of which 22 species and 209 trees were planted in the buffer zone, 8 species and 71 trees in the shade zone, 16 species and 266 trees in the visual landscape zone, and 4 species and 54 trees in the ecological landscape zone. The trees were divided into grades based on their assessment score and were statistically grouped by the functional zone in where they are planted and by tree species to verify their significance. The tree shape assessment was an average of 56.6 points and the tree growth assessment was an average of 76.0 points. Using the results of the tree assessments, the tree standards for each functional space were identified and a concept of optimum planting and cultivating was applied. When applying the shape assessment results by zone to the concept of planting, since trees for buffering require high functionality they received E's, the lowest grade; as trees for ecological landscaping require diverseness and naturalness, they received D's; since trees for shading require utilization, they received C's as trees with branching at the main stems were considered; and since trees for visual landscaping required aesthetical value, they received A's and B's. When applying the growth assessment results by zone to the concept of planting, based on planting foundations of favorable and poor, for buffering, visual landscaping, and ecological landscaping, trees from grades A to E could be planted, and for shading, trees from grades A to C could be planted. For a cultivation plan that could improve the growth of the trees, we proposed that the topography of the land be selected considering the tree's characteristics and that a method of pot seeding be used. Also, to improve the shape of the trees, we proposed that poles be used to improve the growth of vertically-straight stems, an appropriate planting density be applied for reasonable branch growth, manage tree shape to maintain good crowning, and better manage fertilization to maintain a reasonable crown density.