• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.431-436
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• 1994

The objective of experiment was to investigate the effects of sowing dates on forage yield and growth characteristics of rye in paddy field cultivation in midwest region of Korea. The field experiment treated with 5 levels of sowing dates was carried out at Yesan from october 1990 to june 1991. The field emergence rate and winter survival rate were decreased with delay in sowing dates by the days from sowing to emergence were took a long period of time. The crop growth rate were increased with early in sowing date. The fresh and dry weight of rye were increased with early in sowing date, but there was no significant differences between sowing date from Oct. 5 to Oct. 25. The highest fresh yield was obtained at flowering stage and the highest dry yield was obtained at milky stage. The ratio of leaf blade and leaf sheath in rye plant were decreased with earlier sowing date and delayed harvest, but the ratio of stem and inflorescence was vice versa.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.305-309
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• 1991

This experiment was conducted to investigate the effect of shattered grain by combine harvesting at the previous year on rice plant emergence at different planting methods and plant characteristics, The results are follows : Combine harvesting greatly influence on shattered grain of Samgangbyeo as Tongil variety (49.5kg/10a) compared to that of Nagdongbyeo as Japonica variety(27.8kg/10a), while Nagdong-byeo showed higher germination rate than Samgangbyeo, whether transplanted and direct seeded. Emergence of volunteer and seed mixture were lower in transplanted than in direct seeded. In variety test. Japonica variety showed higher emergence of volunteer rice and seed mixture than Tongil variety. Generally, no significant difference in yield components were observed with different varieties by the volunteer rice. But the volunteer rice caused by combine harvesting decreased culm length, panicle length, spikelet number, panicle number and ripening ratio. except l000-grain weights.

• Journal of Korean Society of Rural Planning
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• v.15 no.2
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• pp.19-26
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• 2009

The purpose of this study is to build Island biogeography in the basic concept of landscape ecology in South Korea by draw relationship between the species side of quantitative habitats and forest area surveyed in the national database based on investigation of the 2nd natural environment. In addition, try to present criterion of habitats character category after understanding habitats character of emergence area side of quality habitats based on the type of formatting. Species and forest area relationship analyzed using correlation analysis and simple regression analysis. Also habitat character limited composition ratio of neighboring land cover and analyzed using hierarchical cluster analysis to classify type of habitat. As a result, we found that forest area is correlated with number of species, forests which is bigger than 100ha are more important of increase in species' population. And according to land cover composition ratio, bird's classified types of forest inner species, forest edge species, forest outer species and mammal's classified types of forest inner species, forest general species, forest edge species. We suggest that study of species-forest area relationship and emergence habitat character be used as some management plans of species' conservation, protection and restoration.

• Korean Journal of Environment and Ecology
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• v.29 no.1
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• pp.7-13
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• 2015

To examine the relationship between competition and environmental factors, the germlings of Ascophyllum nodosum (L) Le Jolis and Fucus vesiculosus L. were cultured in monocultures and mixtures of the two species under two different exposure and nutrient levels. Both intra- and inter-specific competition were examined in comparison of the mortality and growth of germlings in monocultures and mixtures of the two species. The mortality of germlings increased with increasing density and emergence periods both in the monoculture and mixtures of the two species, and the mortality of Ascophyllum was significantly higher than that of Fucus both in submerged and emerged treatments. The growth of germlings of both species reduced with increasing density but F. vesiculosus always grew faster than Ascophyllum. The values of log output ratio were more than 0.1, indicating that Fucus 'won' in the competitive battles with Ascophyllum under two nutrient- and air-exposure levels. Log output ratio was greater in high than in low nutrients, indicating that the growth of Fucus is more enhanced than that of Ascophyllum in high nutrients. In the present study, the outcome of inter specific competition between germlings of Fucus vesiculosus and Ascophyllum nodosum was slightly altered by duration of emergence and nutrient concentration, but not to such an extent as to change the outcome.

• Journal of Life Science
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• v.7 no.4
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• pp.347-354
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• 1997

Some attempts were made to investigate the gentic characteristics of the brown planthopper(BPH), Nilaparvata lugens Sta${\aa}$l, biotypes. In terms of egg and nymphal periods, egg hatcgability, emergence ratio, and population change of BPH and plant damage of rice cultivars by the infestation of BPH biotypes and their hybrid progenies in field conditions. The egg and nymphal periods of the three of BPH biotypes and their hybrid progenies on Dongjinbyeo with no resistance gene were shorter than on rice cultivars with resistance gene. But the periods of biotype-2(♀) X 2(♂) (E) on Samgangbyeo with Bph-1 gene and biotype-3(♀) X 3(♂)(I) on Mirying 63 with bph-2 gene were as short as on Dongjinbyeo. The egg hatchability and emergence ratio of the three Bph biotypes and their hybrid progenies on Dongjinbyeo were higher than on the other rice cultivars, and those of E on Samgangbyeo and I on Miryang 63 were as high as on Dongjinbyeo. In rice paddy field, biotype-1(♀) X 1(♂)(A)$\sim$I infested on Dongjinbyeo, E onSamgangbyeo, and I on Miryang 63 were increased their population densities remarkably in next generation. Dongjinbyeo infested by A$\sim$I, and Myryang 63 infested by I were hopperburned at 60 days after infestation and had a damage rating of 0.9. But Samgangbyeo infested by E was no hopperburn(damage rating: 7.3) though it showed high BPH population at 60 days after infestation.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.174-176
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• 2006

The experiments were conducted by supplying hosts with natural food(chestnut, peach, Quince). The developmental difference of peach pyralid moth, Dichocrocis punctiferalis was examined in the laboratory under three different natural food regime. The periods of egg, larva and pupa were $6.01{\pm}0.07$, $12.23{\pm}0.03$ and $13.32{\pm}0.01$ days on the chestnut fruit, $6.21{\pm}0.01$, $18.69{\pm}0.02$ and $13.38{\pm}0.03$ days on the peach fruit and $7.02{\pm}0.04$, $22.62{\pm}0.04$ and $13.44{\pm}0.14$ days on the quince fruit, respectively. The growth of D. punctiferalis larva was better chestnut fruit than other tested fruits. The rates(%) of hatching, pupation and emergence were 94.0, 57.0 and 63.3 on the chestnut fruit, 89.2, 77.8 and 85.7 on the peach fruit and 79.6, 52.6 and 70.7 on the quince fruit, respectively. The survival rate(%) of D. punctiferalis from hatching to emergence were 31.0 on the chestnut fruit, 4.8 on the peach fruit and 14.3 on the quince fruit, respectively. The sex ratio (female: male) of all pupae obtained on the tested natural food fruits were 52.7 : 47.3. The sex ratio of D. punctiferalis reared on three difference food fruits were no significantly. It can be used a as the basic research for the study of D. punctiferalis.

• Asian Journal of Turfgrass Science
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• v.2 no.1
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• pp.59-64
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• 1988

This study was carried out to investigate the classification and the growing charicteristics of weed species in a newly formed lawngrass land. The results obtained are summarized as follows: 1)Weed population in a newly formed lawn field consisted of 30% of Gramineae, 15% of Compositae, and 12% of Leguminosae family. 2)Percentage of weed emergence between April and May was 39.4%. The same amount of weed emergence was observed at the period of September and October, where as the percentage was 21.2% at the period of March and April. 3)The population ratio of flowering date of weed species was in order of 48.5% July and August, 30.3% in May and July, 12.1% in March and April, and 9.1% in September and October. 4)Weed classification by life cycle showed 39.4% of biennials, 33.3% of annuals, and 27.3% of perennials. 5)Weed species were grouped according to the plant height. The ratios of each group were 33.3% of 20~40cm group, 27.3% of 40~60cm group, 24.2% of shorter than 20cm group, and 15.2% of taller than 60cm group.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.370-375
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• 1996

This study was conducted to find out the feasibility in direct seeded rice cultivation on the reclaimed saline soil. Seedling emergence was tested under the different application rates of rice straw and seeding depth, and also under combined treatments soil moisture regimes and seeding depth on saline soils in a greenhouse. The comparison of seedling stand and yield performance of rice in rotary till after broadcast seeding and in non-plow after broadcast seeding were tested on a field that reclaimed saline soil. Seedling emergence ratio in application of rice straw(4 and 6 tons /ha) was higher than that in non-application of rice straw. Seedling emergence and plant height were remarkably increased with the shallow seeding depth in the application of rice straw(4 tons /ha). The seedling emergence under proper soil moisture condition(25%) was higher than that under excess soil moisture condition(35%). Under proper soil moisture condition, the plant height was increased with the shallowed seeding depth. The number of seedling stand per m$^2$ in non-plow after broadcast seeding was larger than that in rotary till after broadcast seeding. Panicle number per m$^2$ in non-plow after broadcast seeding was much larger than that in rotary till after broadcast seeding and the yield showed the same trends as panicle number.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.307-313
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• 2003

Japanese pine sawyer, Monochamus alternatus, is a primary vector of pinewood nematode, Bursaphelenchus xylophilus in Korea. Emergence characteristics of the adults were studied in Jinju, Korea using dead pine logs in which the larvae of the sawyer overwintered from 1999 to 2002. Emergence data showed that the adults began to emerge out of the logs in sunny place from May the 15th in average of the four years. Cumulative emergence ratio (CER) reached at 50% at mid-June, and the emergence terminated by early or late July depending on years. In shady place, however,50% CER was reached 17 days later than in sunny place. The 50％ CER of males reached 1 to 4 days earlier than that of females depending on years. Of the adults emerged from the logs collected from February to April in 2001, 97.6％ was univoltine, and the rest was biennial which emerged from May to July of the next year. Female and male adults emerged throughout 24 hours; 32.3% of the total adults emerged from 8 to 12 a.m. It took 68.0 seconds for the adults to escape from pine logs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.495-501
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• 1994

This experiment was carried out to investigate the proper seeding methed for direct seeding culture of rice in puddled soil at ill-drained paddy field. Mangeumbyeo was seeded on May 11 with drill seeder attached to cultivater, dibbling seeder attached to transplanter and power dust blower. And to determine the proper flooding time after seeding, Mangeumbyeo was seeded on May 7 and June 1 with drill seeder. Emergence ratio wasn't significantly different between drill seeder seeding and dibbling seeder seeding but emergence was very low with power dust blower. Working hour for seeding was shortened in the order of power dust blower, drill seeder and dibbling seeder, and these seeding methods saved the working hour remarkably compared with machine transplanting of infant seedling by omitting the procedures of raising seedling and transplanting. Lodging occurred slightly in all seeding methods. However, yield wasn't significantly different between machine transplanting of infant seeding and direct seeding culture in puddled soil except power dust blower. When field was flooded on seeding date, the emergence period was shortened, emergence ratio was increased and weed occurrence was decreased. Yield was highest when flooding was done on seeding date as the number of panicle per m$^2$ and the number of spikelets per m$^2$ were higher than any other flooding time.