• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.887-894
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• 2011

To evaluate the effects of abiotic factors of paddy fields on greenhouse gases (GHGs) emissions from rice paddy fields, $CH_4$ emission amounts were investigated from rice paddy fields by different soil organic matter contents, paddy types, and agricultural climatic zone in Yeongnam area during 3 years. $CH_4$ emission amounts according to soil organic matter contents in paddy field were conducted at having different contents of 5 soil organic matters fields (23.6, 28.7, 31.0, 34.5, and $38.0g\;kg^{-1}$), The highest $CH_4$ emission amount was recorded in the highest soil organic matters plot of $38.0g\;kg^{-1}$. High correlation coefficient (r=$0.963^{**}$) was obtained between $CH_4$ emissions from paddy fields and their soil organic matter contents. According to paddy field types, $CH_4$ emission amounts were investigated at 4 different paddy fields as wet paddy, sandy paddy, immature paddy, and mature paddy. The highest $CH_4$ emissions was recorded in wet paddy (100%) and followed as immature paddy 64.0%, mature paddy 46.8%, and sandy paddy 23.8%, respectively. For the effects of temperature on $CH_4$ emissions from paddy fields, 4 agricultural climatic zones were investigated, which were Yeongnam inland zone (YIZ), eastern coast of central zone (ECZ), plain area of Yeongnam inland mountainous zone (PMZ), and mountainous area of Yeongnam inland mountainous zone (MMZ). The order of $CH_4$ emission amounts from paddy fields by agricultural climatic zone were YIZ (100%) > ECZ (94.6%) > PMZ (91.6%) > MMZ (78.9%). The regression equation between $CH_4$ emission amounts from paddy fields and average air temperature of Jul. to Sep. of agricultural climatic zone was y = 389.7x-4,287 (x means average temperature of Jul. to Sep. of agricultural climatic zone, $R^2=0.906^*$)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.115-124
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• 1968

It was shown that the most desirable characters for kenaf are high-fiber weight and moderately early maturity. Therefore, the objectives of this research on this crop is to find varieties possessing these characteristics. The experiments covered in this report provided new information relative to segregation, mode of inheritance, estimate of the number of genes involved in fiber weight and their response to short day length of 10 hours and the qualitative characters, such as, color of stem, capsule, petiole and shape of leaves. The associations which exist among these characters are also indicated. Fiber weight per plant, days to flowering, Stem color, Petiole color, Capsule color, and shape of leaves were studied in parental, $F_1$.$F_2$and backcross populations of a cross between Dashkent, a low-fiber weight but early maturing kenaf variety, and G 38 F-1, a high-fiber weight but late maturing kenaf variety. Crosses were made using the varieties, Dashkent and G 38 F-1 as parents. The Dashkent parent had the following characteristics: green stems, capsules and petioles and lobed shaped leaves; 105.8234 mean-days to flowering in the field, and 106.9222 mean-days under 10 hours short day treatment. The other parent, G 38 F-1 had red stems yellow capsules and red petioles and unlobed shaped leaves; 149.8921 mean-days to flowering in the field, and 62.3684 mean-days under 10 hours short day treatment. Both of the parents, $F_1$, $F_2$, $BC_1$ ($F_1$ X Dashkent, ) and $BC_2$($F_1$ ${\times}$ G38F-1) of the kenaf cross were grown at the Crops Experiment Station, Suwon, Korea in 1965. Color of stems, petioles and capsules, and shape of leaves were noted to be simply inherited as a single factor. Red stem color was dominant over green stem color, red petiole color was dominant over green petiole, lobed shaped leaves were dominant over unlobed shaped leaves and yellow capsules were dominant over green capsule. It was, also, noted that the factor for color of petiole was linked with the factor for shape of leaf with a 11.9587 percent recombination value, however no interaction or linkage were found among the color of stem and capsule color. Using Powers partitioning method, theoretical means and frequency distributions for each population, the days to flowering were calculated with the assumption that two gene pairs were involved. The values obtained fitted the theoretical values. In general this would indicate that Dashkent and G 38 F -1 were differentiated by two gene pairs. Heritability values were calculated as the percent of additive genetic variance. Heritability value of days to flowering, 89.5% in the broad sense and 79.91% in the narrow sense, indicated that the selection for this character would be effective in relatively early generations. Particularly, high positive correlations were found between days to flowering and the color of petioles and shape of leaves. However, there was no relation between days to flowering and capsule color nor between these and stem color. On the basis of the results of this experiment there is evidence that the hereditary factor for shape of leaves and the color of petioles is linked with an effective factor or factors for the characters of days to flowering. The association was sufficiently close to offer a possible simple and efficient means of selection for moderately early mat. uring plants by leaf shape and petiole color selection. Again using Powers partitioning method the frequency distribution for each population to the fiber weight were calculated with the assumption that two gene pairs, AaBb, were involved. Both phenotypic and genotypic dominance were complete. The obtained value did not agree with the theoretical value for $F_2$ and $BC_1$ ($F_1$ ${\times}$ Dashkent.) It seems that Dashkent and G 38 F-1 were differentiated by two major gene pairs but some the other minor genes are necessary. It is certain that the hereditary factor for shape of leaves and color of petioles is linked with an effective factor or factors for fiber weight. Also, high. yielding plants with moderately early maturity were found in the $F_2$ population. Thus, simultaneous selection for high-fiber yield and moderately early maturing plants should be possible in these populations. Phenotypic and genotypic correlation coefficients between fiber weight per plant and days to flowering, stem height and stem diameter were calculated. In general, genotypic correlations are higher than the phenotypic correlation. The highest correlation is found between stem height and fiber weight per plant (0.7852 in genotypic and 0.4103 in phenotypic) and between days to flowering and fiber weight per plant (0.7398 in genotypic and 0.3983 in phenotypic.) It was also expected that the selection of high stem height and moderately early maturing plants were given the efficient means of selection for high fiber weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.54-87
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• 1975

The effects of various weather factors on yield components of rice, year variation of yield components within regions, and regional differences of yield components within year were investigated at three Crop Experiment Stations O.R.D., Suweon, Iri, Milyang, and at nine provincial Offices of Rural Development for eight years from 1966 to 1973 for the purpose of providing information required in improving cultural practices and predicting the yield level of rice. The experimental results analyzed by standard partial regression analysis are summarized as follows: 1. When rice was grown in ordinary seasonal culture the number of panicles greatly affected rice yield compared to other yield components. However, when rice was seeded in ordinary season and transplanted late, and transplanted in ordinary season in the northern area the ratio of ripening was closely related to the rice yield. 2. The number of panicles showed the greatest year variation when the Jinheung variety was grown in the northern area. The ripening ratio or 1, 000 grain weight also greatly varied due to years. However, the number of spikelets per unit area showed the greatest effects on yield of the Tongil variety. 2. Regional variation of yield components was classified into five groups; 1) Vegetation dependable type (V), 2) Partial vegetation dependable type (P), 3) Medium type (M), 4) Partial ripening dependable type (P.R), and 5) Ripening dependable type (R). In general, the number of kernel of rice in the southern area showed the greatest partial regression coefficient among yield components. However, in the mid-northern part of country the ripening ratio was one of the component!; affecting rice yield most. 4. A multivariate equation was obtained for both normal planting and late planting by log-transforming from the multiplication of each component of four yield components to additive fashion. It revealed that a more accurate yield could be estimated from the above equation in both cases of ordinary seasonal culture and late transplanting. 5. A highly positive correlation coefficient was obtained between the number of tillers from 20 days after transplanting and the number of panicles at each(tillering) stage 20 days after transplanting in normal planting and late planting methods. 6. A close relationship was found between the number of panicles and weather factors 21 to 30 days, after transplanting. 7. The average temperature 31 to 40 days after transplanting was greatly responsible for the maximum number of tillers while the number of duration of sunshine hours per day 11 to 30 days after transplantation was responsible for that character. The effect of water temperature was negligible. 8. No reasonable prediction for number of panicles was calculated from using either number of tillers or climatic factors. The number of panicles could early be estimated formulating a multiple equation using number of tillers 20 days after transplantation and maximum temperature, temperature range and duration of sunshine for the period of 20 days from 20 to 40 days after transplantation. 9. The effects of maximum temperature and day length 25 to 34 days before heading, on kernel number per panicle, were great in the mid-northern area. However, the minimum temperature and day length greatly affected the kernel number per panicle in the southern area. The maximum temperature had a negative relationship with the kernel number per panicle in the southern area. 10. The maximum temperature was highly responsible for an increased ripening ratio. On the other hand, the minimum temperature at pre-heading and early ripening stages showed an adverse effect on ripening ratio. 11. The 1, 000 grain weight was greatly affected by the maximum temperature during pre- or mid-ripening stage and was negatively associated with the minimum temperature over the entire ripening period.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.65-74
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• 2008

Traffic management is becoming an important issue in turfgrass practise on golf course. The objective of this study was to investigate the combined impact of different traffic times and types of fertilization. Traffic treatment was applied in morning (AM), noon, and afternoon (PM). Fertilizers used include faster-release fertilizer (21-17-17) and slow-release fertilizers (12-6-18, 11-3-22, 20-3-20, 10-3-10). Experiment was conducted from Oct. 1 to Nov. 30, 2005 on a nursery putting green of Incheon Grand Golf Club. The growth and quality of creeping bentgrass (Agrostis polustris cv. 'Seaside II') were evaluated on visual leaf color, leaf texture, shoot density, and root length. The measurement at 20 days after treatment, turfgrass color and leaf texture showed the best result on 10-15-10 + Noon-traffic plot. Turf quality and traffic tolerance were not different at Am and Pm traffic treatment. However, traffic stress in early morning and late evening caused the most severe damage to the turfgrass. Shoot density was the highest in 10-15-10 + Noon-traffic treatment but root length was not different among treatments after 30 day measurement. Among the fertilizers, slow release fertilizer resulted in higher turf quality and traffic tolerance than fast release fertilizer, however, shoot density did not showed a significantly different. For the fast recuperation of turfgrass from traffic injury in the early winter, it is recommended to avoid early morning and late evening traffic such as cup replacement and other maintenance practise. It is also recommended to delay the first tee-up time and ending early for last tee time during cold weather season.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.551-558
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• 2011

This present study was performed to analyze the efficiency and volatility of a porous film containing $Chamaecyparis$ $obtusa$ extract as a method to effectively package food compounds. Phytoncide was contacted the state of gas and showed effective antimicrobial properties. Limonene can be distilled without decomposition as a relatively stable terpene and was one of the extract components. $Chamaecyparis$ $obtusa$ essential oil. The optimal solvent composition was a ratio 5:20:0.3 of T-500:ethanol:hardener to effectively manufacture film containing phytoncide essential oil and the minimum antibacterial concentration was 2%. The films were made under different conditions(A-50LF1, A-25SF2, B-50SF1, C-50LF1, C-25SF2 and D-50SF1) containing phytoncide and the amounts of limonene inside the 1-L reaction chamber depending on storage were measured by gas chromatography-mass selective detention. The results showed that the 25SF2(width, 25 mm; length, 20 cm) revealed more amount of limonene compared with 50LF1(width 50 mm, length 20 cm). We confirmed that the gas emission amount showed a better layer on the film side than on the internal film. An effect of film thickness on phytoncide emissions was observed in that the amounts was less than the expectation for a thicker film at the beginning time, but the emitting amounts increased with increasing storage periods. In the storage testing of various films at $35^{\circ}C$ and 70% humidity for 14 days, 25SF2 showed longer preservation compared with that of 50LF in the case of bread. $C.$ $obtusa$ essential oil is a useful fresh ingredients, hence, analysis of limonene emission kinetics from various film was helpful to develop films with an optimal antimicrobial effect, and will allow application of such films in food packaging systems.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.224-230
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• 1981

Threshing forces of seven varieties, that is, three Japonica type varieties-Irri 348, Irri 345, and Milyang 15, and four Indica type varieties-Milyang 23, Irri 342, Suweon 294 and Suweon 287-, which have been cultivated in the standard fertilization field being at Chungnam Provincial Office of Rural Development, Youseong, Chungnam-do, they were measured every other day in the period from September 28 to October 20 which were included the proper harves ting time. Also the threshing forces were checked in three-dimensional directions. Relationships between threshing forces and moisture contents of the unthreshed rice were examined in the laboratory as dried in the natural condition. The results of this study were as follows; 1. The mean threshing force of Japonica type varieties was about 1969r. and that of Indica type varieties was about 113gr. when external force was loaded in the direction parallel to the grain. 2. The threshing force bent to the grain was about 9.8through 28.2gr. equal to 7 through 21 percent to the threshing force parallel to the grain in Indica type varieties meanwhile about 59.8 through 115.0gr equal to 33 through 50 percent in Japonica type varieties. 3. Under the warmer temperature than $0^{\circ}C$, the change of threshing forces was not great in this experimental period on the harvesting dates. 4. The threshing force decreased s lightly as moisture content decreased in natural drying under the shade after cutting. 5. The threshing force of the lower portion was a little biger than that of the upper portion in an ear.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.436-446
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• 2020

In this study, we verified the effects of organic amendment application based on soil testing in potato cultivation. The application rate of organic amendments was determined based on the inorganicization rate of nitrogen, phosphoric acid, and potassium in the organic amendments. There was no significant difference in the length, stalk number, stalk diameter, and leaf color of potato plants under organic amendment application compared with those under chemical fertilization. The quantity of potato tubers and yield of marketable tubers under organic amendment application were higher than those under chemical fertilization. The top fresh weight and top-to-root ratio were the highest under organic amendment application, followed by those under chemical fertilization and the control. The inorganic nitrogen content in the leaves and stems of potato plants was the highest under chemical fertilization. There was no difference in the phosphoric acid content between the potatoes under chemical fertilization and those under organic amendment application. The potassium content in potatoes was higher under chemical fertilization than that under organic amendment application. While the change trend of inorganic nitrogen content in the roots was similar to that in the leaves and stems, the potatoes under organic amendment application, with the highest yield, showed the highest dry weight. The tuber weight showed a positive correlation with plant length, stalk number, and stalk diameter. The higher the weight of the tuber, the higher the weight of the marketable tuber, and the higher the top fresh weight, the higher the yield. Therefore, to increase yield, it is necessary to supply nutrients to improve the top fresh weight to the optimal level. There was no difference in the utilization efficiency of nitrogen and potassium between the potatoes under chemical fertilization and those under organic amendment application. The utilization efficiency of phosphoric acid was increased by 0.1% in potatoes under organic amendment application compared with that under other treatments. Regarding soil chemistry after harvest, the soils under organic amendment application showed a higher electrical conductivity and higher nitrogen and phosphoric acid content than those under other treatments. Therefore, the organic amendment method used in this study can be an alternative to chemical fertilization. It is also advantageous for the cultivation of subsequent crops in potato fields.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.239-250
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• 2002

Evaluation works of oat in mixture with rye on forage yield have not been reported. The objective of this study was to determine yield and quality of forage mixture as affected by maturity of rye cultivar and oat-rye seeding rate at Suweon from 1999 to 2000. The experiment was arranged in a split plot design with three replications. Main plots consisted of maturity of rye. such as early(cv. Koolgrazer) and late(cv. Kodiak)maturing cultivars. Sub-plots consisted of seeding rate (T1: Oat 2000 and rye 0kg/ha, Ts: Oat 150 and rye 40kg/ha, T3: Oat100 and rye 80kg/ha, T4: Oat50 and rye 120kg/ha. and T5: Oat0 and rye 160kg/ha). Crude protein(CP) content of oat-rye mixture harvested in the fall was not influenced by maturity of rye cultivar, but that of oat-rye mixture was increased from 13.6 to 19.3% as the seeding rate of rye increased(P<0.05), however, maturity of rye cultivar significantly affected CP content of oat-rye mixture in the spring(P<0.01). Acid detergent fiber(ADF) content of oat-rye mixture harvested in the spring was not significantly affected by rye cultivar, but the ADF was decreased from 27.8 to 20.7% as the seeding rate of rye increased(P$<$0.01). When rye was harveste in the spring, ADF content of late maturing cultivar 'Kodiak' was shown as 28.0%. This was lower than that of early maturing cultivar 'Koolgrazer' which was shown as 35.8%(P$<$0.01). Among treatments, neutral detergent fiber(NDF) and in vitro dry matter digestibility(IVDMD) of oat-rye mixture showed a similar trend made on ADF. In this experiment, the highest forage yield (12.356kg/ha) was obtained from early maturing rye cultivar and seeding rates of 100kg/ha of oat and 80kg/ha of rye mixture. A significant interaction between maturity of rye cultivar and seeding rate was found(P$<$0.01). The above results indicate that an early maturing rye cultivar at the seeding rate of 100kd/ha in mixtures with 80kg/ha of oat could be recommended as a succeeding cropping system after corn for silage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.265-272
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• 2002

Forage breeding laboratory of National Livestock Research Institute, R.D.A. has made interspecific hybrids of Lolium multiflorum $\times$ L. pratensis and intergeneric hybrids of Lolium $\times$ Festuca since 1984, and has collected ecotypes of Italian ryegrass since 1991. Growth characteristics of these hybrids and ecotypes were researched, and then these clone lines were named. Among these clone lines, the several clones that have polen fertility, high cold-tolerance, and similar heading time were used for making synthetics, Naehan 6, 7, 8, 9, with polycrossing method in 1997. Field experiments were carried out to compare the mophological and agronomical characteristics and forage productivity and quality of the synthetics with those of Italian ryegrass varieties, Barmultra and Hwasan 101. in Suwon and Yonchun from 1999 to 2000. Heading time of the synthetics were 22th to 24th May that belong to late-mature types to be similar to that of Barmultra and Hwasan 101 in Suwon. The synthetics were 101 to 106 c3n in plant length, medium or thick in thickness of stem, dark peen in leaf color, broad and long in flag leaf, strong in lodging resistance, and excellent in regrowth. Winter survivals of the synthetics were no different from that of Barmultra or Hwasan 101 in Suwon, but better than that of Barmultra or Hwasan 101 in Yonchun where was -10 to -12$^{\circ}C$ of minimum average air temperature in January or February. Dry matter(DM) yields of the synthetics were similar to DM 8,238kg per ha of Barmultra in Suwon, but in Yonchun, were more 7 to 13% than DM 7,291kg per ha of Barmultra. Forage qualities, IVDMD, ADF, NDF and TDN of the synthetics were lower than those of Hwasan 101, but higher than those of Barmultra.

• Research in Plant Disease
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• v.17 no.3
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• pp.288-294
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• 2011

Rice bakanae disease, caused by the fungus Fusarium fujikuroi, is one of the most important rice diseases and distributed widely in Asia. Resistance screening system in rice field had been established. However, the evaluation results of the system vary according to the environmental conditions when the test is conducted. To develop precise and rapid evaluation method of disease resistance of rice to bakanae disease, in vitro screening system was attempted in this study. The six cultivars namely, 'Nampyeongbyeo', 'Junambyeo', 'Chucheongbyeo', 'Samcheonbyeo', 'Odaebyeo' and 'Hwasinbyeo' were tested. They were planted onto MS agar medium (10 ml) in test tube ($450\;mm{\times}{\phi}30\;mm$) and incubated at $25^{\circ}C$ and $28^{\circ}C$ in growth chamber under 12 hr light condition. Symptoms of over growth appeared a few days after seeding and then seedling were withered 2-3 weeks after over growth. The disease symptoms such as leaf dryness on top of rice were appeared in the 'Nampyeongbyeo' from 28 days at the concentration of $10^5$ spores/ml culturing at $28^{\circ}C$ and then withered completely 35 days after seeding. Whereas the other varieties withered entirely 19-23 days after seeding. Using the in vitro seedling screening method, 72 rice varieties were investigated to select resistant cultivar. Finally, two resistant cultivars ('Nampyeongbyeo' and 'Inwolbyeo') and seven moderately resistant cultivars ('Hwadongbyeo', 'Seokjeongbyeo', 'Samgwangbyeo', 'Sampyeongbyeo', 'Nonghobyeo', 'Heukjinjubyeo' and, 'Joanbyeo') were selected. If in vitro seedling screening method was used for evaluation of bakanae disease resistance, it would be completed within 35 days after sowing of rice seed.