• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.133-137
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• 1969

This experiment was conducted to determine the optimum row width and plant spacing within row under the tropical environment for a leading soybean variety Palmetto and it was carried out at Eakmat Experiment Station in Vietnam. The experiments were arranged in a split plot design with four replications and the test was repeated twice in two years. Variations for seed yield due to the distance between rows were significant at 1 per cent level in 1967 test(dry season growing) and at 5 per cent level in 1968 test. Significant differences for plant height, lodging, maturity, number of branches per plant, and number of pods per plant due to the row width were not found in both tests, while significant differences in difference spacing within row was found in all traits studied. Interaction between width of row and spacing within row for seed yield and plant height were found at five percent level in 1967 test. These results indicate that close planting may increase in seed yield and plant height in both seasons, and decrease in loadging. From these studies, one could be understood that the plant population, particularly in dry season, plays decisive roles on seed yield in soybean culture, and the maximum plant height and minimum value of lodging index were also observed in closest spacing plots. The highest soybean yield in late planting would be expected by a combinations of 30 cm(between rows)${\times}$5cm(between hills) plot, while 40cm ${\times}$ 5cm planting method would be suggested for rainy season growing. Highest seed yield was obtained at closet spacing in both dry and rainy season, and these results led to drilling method in seeding where about 20 seeds per meter of row could be recommended. Besides the seed yield, the close planting may produce some advantages, such as increase plant height and decrease lodging, weeds and erosion of surface soil.

• Journal of the Korean Home Economics Association
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• v.26 no.3
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• pp.43-51
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• 1988

This study is intended to investigate the demographic characteristics and socio-economic status of students, and to reveal the correlations between food habit and health condition by Todai health Index. The results of this study were summerized as followes: 1) the sex ratio of the subjects was 309 males: 129 females. Mean score of the food habit was 7,56 in males and 8.88 in females. The subjects were included in Fair and Poor group generally. Food habit score of students living their own home were significantly higher generally. Food habit score of students living their own home were significantly higher than those of the others (Lodging & Relatives, Self-Boarding, Dormitory, and so forth). 2) In males and females, mean of height and weight were 171.6cm, 62.1kg and 159.9cm, 50.9kg, respectively. Though there was insignificant difference in the physical index according to food habit score in general, there was a special trend in case of male that the higher food habit score they have, the higher physical index they get. The subjects with low food habit score showed the higher THI point in Life-irregularity, Straight-forwardness, depression and Sufferings than those with high food habit score. The female subjects with high food habit score showed the lower THI point in depression, on the contrary, showed higher in vanity. There was significant correlation between instant food, drinking and smoking and THI point.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.731-737
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• 1995

This experiment was carried out at National Crop Experiment Station in 1994 to obtain basic information of growth characters and yield of rice under various nitrogen split application methods on different soil textures in direct seeding on dry paddy. Hwaseongbyeo sown on April 27 by flat drill seeding, and irrigation was done at 3 leaf stage after seedling establishment. Number of seedling stand was 159~177 seedlings per $m^2$ regardless of soil texture and nitrogen application method. Number of panicle per unit area in loam was higher than in sandy loam, and it also was higher in top dressing plots, which were 3 times application at rate of 40-30-30% (3rd leaf stage -7th leaf stage -panicle initiation stage) and 4 times application 10-30-30-30%(basal-3rd leaf stage -7th leaf stage -panicle initiation stage), than in conventional method. Leaf colour, leaf area index and dry matter production at heading stage were highest at top dressing plots among the nitrogen application methods in both sandy loam and loam. Lodging index in top dressing plots increased by low breaking weight with long culm. There were field lodging of degree 3 in top dressing plots. Rice yield in sandy loam, loam increased by 7~9%, 6~9% in top dressing of nitrogen, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.551-557
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• 1996

In order to establish a labour-saved and environment friendly paddy rice system in southern Korea, no-tillage paddy system was proposed and investigated from 1992 to 1993. Basically this system includes a complete return of crop residules into the soil, and zero-tillage. In an effort to minimize labour requirement in rice farming, several cultivars were directly sown and grown under the system and the characteristics of the growth and yield potential of the cultivars were compared with those grown in an ordinary paddy soil. Joryeongbyeo, Dongjinbyeo, Daeyabyeo and Calose rices showed high level of seedling establishment in the no-tillage padddy system. However, the value was significantly lower than in those of the cultivars direct-sown in an ordinary tillage paddy condition. The rice direct-sown and grown under the no-tillage paddy system showed significantly decreased number of tillers per square meter and plant height, but increased ripened grains. The lodging-related characteristics of rice plant, such as band breaking weight, the length of top 3rd ∼4th internodes, the height of weight center, and lodging index, were observed positive aspects in cultivars such as Hwasungbyeo, Hwayongbyeo, Joryeongbyeo, Calose and Calose 76 and being considered adaptable to direct-sown under the no-tillage paddy system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.457-462
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• 2004

Lodging is one of the most serious problems in soybean cultivation. Therefore, improved cultural methods to reduce lodging as well as to increase photosynthetic ability should be mostly desirable to increase soybean production. The test variety was 'Hwangkeumkong' which was pinched at V7 stage. The greatest difference in canopy height between rows was shown when every other row was pinched, which also recorded the most effective reduction in lodging. The 9th leaf of soybean plants in non-pinching rows of alternative non-pinching and pinching plot showed the highest photosynthetic ability due to the greatest difference in canopy height. Although leaf area index was higher in pinched rows in average after 17 August, alternative pinching of every other row recorded the highest LAI on 5 September. Alternative pinching of every other row resulted $2\~14\%$ higher yield than non-pinching or complete pinching due to the increases of number of grains in the upper part of main stem and average grain weight of non-pinching rows and in alternative pinching.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.324-329
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• 1988

This experiment was conducted to find the effect of paclobutrazol application of 12, 18, 24g/10a at 35, 25 and 15 days before heading on the characters related with lodging, growth and yield of paddy rice plants in 1985. Culm lengths were reduced from 7% to 12% by paclobtrazol application of 35, 25 and 15 days before heading. The paclobutrazol caused more short internode, thick well of internode and wide section area of internode than the untreated control. The lodging index were remarkably decreased by paclobutrazol application and also the field lodging of rice plant was not observed. The number of spikelet per panicle was decreased by paclobutrazol application at 35 days before heading and 25, but ripened grain ratio and 1000 grain weight were higher than the untreated control. Paclobutrazol applications increased more from 5% to 8% than untreated control on the grain yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.294-299
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• 1991

Eight naked barley cultivars were grown in three production systems to select proper cultivars for dual production of forage and grain and to determine production system x cultivar interactions. In the forage systems. barley was seeded on September 27 and October 17, harvested for forage on November 1. December 10 and February 12 from the September 27 planting (forage system I) and on December 10 and February 12 from the October 17 seeding(forage system II). In the grain-only system, barley was planted on November 5. In forage system I, oven-dried forage yields of eight cultivars ranged 195 to 296kg/10a and Saessalbori and Naehanssalbori yielded significantly higher than the other cultivars recording 280 and 296kg/ l0a, respectively. In forage system II, oven-dried forage yields of eight cultivars ranged 106 to 143kg/10a showing no significant difference among cultivars. Production system x cultivar interactions were significant for lodging at maturity, powdery mildew rating, 1000 kernel weight and grain yield. Leaf area index and biomass at heading, no. of spikes per $m^2$, no. of kernels per spike and test weight were not affected by the production system. Forage utilization delayed heading by 3 days and reduced culm length, spike length, lodging due to heavy rain on May 5 and lodging at maturity except for Songhagbori and Naehanssalbori. Forage utilization did not significantly affect grain yield from the September 27 planting but reduced 9% from the October 17 planting. while Saessalbori and Hyangcheonggwa 1 yielded significantly less than in the grain-only system. Songhagbori appears to be a proper cultivar for dual production of forage and grain in Cheju, considering forage and grain yields. and lodging and powdery mildew resistance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.14-21
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• 1997

This experiment was conducted to identify the growth and yield differences in rice cultural types: Broadcasting on flooded paddy surface(BF), drilling on flooded paddy surface(DF), puddled-soil drill seeding(PD), drill seeding on dried paddy flat(DD), and machine transplanting of lO-day old seedling(MT) at National Honam Agricultural Experiment Station in 1995. Among the cultural types of direct seeding, the number of seedling stand showed high in order of DD>BF>DF>PD. Tillering at early growth stage was faster in MT and effective tiller showed higher in MT than in direct seeding. Growth duration from seeding to heading was longer in direct seeding than in MT for 2-13 days of Dongjinbyeo and 10-18 days of Nonganbyeo. Root distribution ratio at the surface soil revealed high in order of BF>DF>PD>DD and MT. Culm wall thickness of 4th internode was thicker in machine transplanting of 10-day old seedling than in direct seeding, and the depth of buried culm showed deep by turns of MT> DD>PD>DF and BF. The height of center gravity and moment related to lodging revealed higher in direct seeding than machine transplanting that resulted high lodging index by turns of BF>DF>DD> PD among the direct seeding cultural type. Lodging was occured seriously in the order of BF>DF>PD>DD =MT in Dongjinbyeo but wasn't significantly different in Nonganbyeo among the cultural type. The yield components and grain yield showed varietal differences but was not significantly different between in MT and in direct seeding, and among cultural types of direct seeding.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.31-38
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• 1992

This study was conducted to investigate the effect of plant growth retardants on the growth and characters related with lodging in rice. The results are summarized as follows. Plant height which is closely related to lodging was significantly inhibited by the application of inabenfide, paclobutrazol, and uniconazole. Among the tested application times, inabenfide, paclobutrazol, and uniconazole were the most effective in inhibiting plant height at 30, 20, 20 days before heading respectively. Inabenfide was markedly effective in reducing the lower (4th) internode length, whereas paclobutrazol and uniconazole were more effective in reducing the upper (3rd and 2nd) internode length. Internode wall of rice plant treated with chemicals was tended to be thickened as compared with control. Heading date was not influenced by inabenfide, but paclobutrazol and uniconazole were inhibited 1 or 2 days in heading date as compared with control. Lodging index was the most reduced when inabenfide was applied 30 days before heading with 160g ai whereas paclobutrazol and uniconazole were applied 15 days before heading with 12, 1.2g ai per 10a, respectively. All the treatments inhibited the lodging of rice but control was completely lodged. Yield treated with these chemicals was prevented by 10-12% of yield decrease occurred by lodging. As a conclusion, inabenfide with 120 or 160g ai at 40 or 30 days before heading, paclobutrazol with 12g ai at 15 days before heading, arid uniconazole with 1.2g ai at 15 days before heading appear to be the most practical application time and rate for preventing lodging in paddy rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.