• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.159-164
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• 1973

This study was carried out in the central part of Korea for three years from 1970 to 1972. Its aim was to investigate the variations of growth and yield of rice varieties of different cultivating methods (transplanting culture, direct sowing culture on irrigated paddy field, and direct sowing culture on non-irrigated paddy field. The results could be summarized as follows; 1. The number of days from sowing to heading by direct sowing culture on irrigated paddy field was remarkably shorter than transplanting culture. Direct sowing culture on non-irrigated paddy field was longer than transplanting culture. 2. The number of panicles showed direct sowing culture on irrigated paddy field was first, direct sowing culture on non-irrigated paddy field was second, and third transplanting culture. But the number of spikelets per panicle was first on the transplanting culture, second on the direct sowing culture on non-irrigated paddy field and third on the direct sowing culture on irrigated paddy field. 3. The weight of the brown rice showed that direct sowing culture on irrigated paddy field produced the highest yield among the cultivating method in all varieties. The transplanting culture increased more than the direct sowing culture on non-irrigated paddy field. The highly productive varieties were Sadominory, Akibale, Suwon 213-1 when the direct sowing culture on irrigated paddy field was used. 4. The correlation between the brown rice yield and the yield components were as follows; in each cultivating method, it showed highly significant positive correlation between the brown rice yield and the 1, 000 grain weight of hulled rice, and between the brown rice yield and the number of the spiklets per panicle in the transplanting culture, in the direct sowing culture On irrigated paddy field between the brown rice yield and the number of spikelets per panicle and between the brown rice yield and the number of panicles, in direct sowing culture on non-irrigated paddy field between the brown rice yield and number of panicles. 5. It showed highly significant negative correlation between the brown rice yield and the number of days from sowing to heading in the direct sowing culture on irrigated and non-irrigated paddy field, but it was showed very low negative correlation in the transplant culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.456-462
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• 2012

In the new changing scenario, the goal of agriculture is shifting from traditional to sustainable and environment-friendly agriculture. Therefore, in this experiment, we analyzed economic efficiency of two methods of rice cultivation i.e. new cultural method and conventional method, at farmers' fields. In the new cultural method, cost of materials and machines (rice-transplanting and sowing machine) was found 245% higher than the conventional method. Depreciation of cost and working hours were also higher in the new cultural method by 1.9 and 1.1 time, respectively. However, cost of seeds and seedbed soil were 44.0% and 49.2% lower and total material cost was 4.4% lower than the conventional method. In the new cultural method, overall working cost of nursery raising and transplanting per 10a was 229.8% higher than the conventional method. However, in spite of high input cost, yield of rice in new cultural method was higher by 6.7% than the conventional method. Our results showed that new cultural method was better than the conventional method except the input cost. If government provide 80% subsidy for machine cost then its input cost will be reduced by 45.4% than the conventional method.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.230-260
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• 1992

The paper was reviewed the research results on weed dynamics and effective control methods in direct-seeded rice crop. Direct seeding method resulted in drastic increment of weed growth compared to transplanting method and also changed in troublesome weed flora. Two to three fold more weeds were harvested at the direct seeded rice and weed flora of dominant species shifted toward $C_4$type grass weeds. Some of the important troublesome weeds in direct seeded rice were Echinochloa crus-galle, Oryza saliva ssp spontanea, Leptochloa chinensis. Setaria viridus. Digitaria adsendens, Sesbania exaltata, Aeschynomene indica, Algae, etc. Yield loss due to weed competiton was about 40-60% for water-seeded and about 70-100% for dry-seeded rice while these for transplanted rice were about 25-35% for mechanical transplanting and about 10-20% for manual transplanting, respectively. Integrated weed management concept was neede to approach weed control effectively. Several cultural technologies were very effective to suppress the weed growth. These were tillage operation, water management, seeding date and seeding rate. Crop residues of barley, rice, wheat, oat and italian ryegrass were also effectivly suppressed the paddy weeds particularly to Potamogeton distiuctus, a perennial broadleaf weed. A pathogen of Epicoccosorus nematosporus identified from Eleocharis kuroguwai was an excellent potential bioagent to control the most troublesome perennial sedge weed of E. Kuroguwai without arising any detrimental effect. The herbicidal efficacy of this pathogen was as high as bentazon herbicide. Plant growth regulator of paclobutrazol (pp-333) was another possible alternative to reduce the herbicide use. In current, herbicide exhibited the most conspicuous results to control weeds in direct-seeded rice even though the application technologies were not fully established. Recommendations for herbicide application were suggested for in both water-and dry-seeded rice in USA, Japan and Korea, respectively. To make better and comprehensive recommendations further studies on weed ecology and herbicide development were emphasized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.115-122
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• 1996

One of the most laborious work in rice farming is transplanting of rice seedling which has been required preparation of nursery bed and care of seedling during one month period. In this research, direct seeding in dry paddy(DS) and direct seeding in wet paddy(WS) were practiced to compare with traditional transplanting(TP) in Suwon. Growth stages in direct seeding were delayed as its planting time was about 21 days later than those of TP. Heading stage of direct seeding at Suwon was delayed about 9 days as compared to transplanting culture. Rice yield was not different between the seeding practises. Working-hour saving was about 17％(DS) and 28％(WS). Production cost of direct seeding was decreased 20％(DS) and 32％(WS), respectively. Amount of rice production per a unit working-hour in direct seeding could increase 14％(DS) and 39％(WS) compared to that of TP, respectively. Therefore, direct seeding could save significantly working hour and production cost without reducing rice yield. WS was more effective than DS in saving labor and production cost. Direct seeding was not efficient method in input of farming energy and agricultural chemicals.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.254-261
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• 2005

To evaluate the effects of cultivar, environment, age and cultivation times on ginsenoside content among 8 wild populations of American ginseng (Panax quinquefolium), the concentrations of 6 ginsenosides in root were determined at the time of collection (T0) of plants from the wild and 1 year after (T1) transplanting the roots to each of two different forest garden locations. Both location and population had significant effects on root and shoot growth. Overall, ginsenoside Rb1 was most abundant. The second most abundant ginsenoside were Re and Rg1, however the contents of them were not significantly different from each other. Concentrations of Rg1 and Re were inversely related. Ginsenoside Re was influenced by population and location. Ginsenoside Rg1, Rb1, Rc, Rb2 and Rd were influenced by population, location and age. Ginsenoside levels were consistently lower but growth was consistently higher at the more intensively managed garden location.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.284-290
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• 1993

In order to improve the adaptability of rice transplanter to seeding with different length when transplanting multicropping rice in south China. The seedling separating planting mechanism is resynthesized in the paper. According to the agronomy requirements of seedling's transplanting, optimum motional path of the tip point of planting needle is obtained. by applying the established kinematic model of the separating planting mechanism, the relevant software is compiled. On the basis of the features of the problem, the constrained optimization method is utilized to solve the problem with 24 restrictions. Thus, the optimum structure parameters are obtained to satisfy the path points accurately.

• Journal of Plant Biology
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• v.13 no.1
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• pp.1-12
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• 1970

The Nongkwang variety was sown directly in the field by the three methods of dibbling, drill seeding and broad-casting in non-, low- and high-salty areas, and compared with the growth of transplanted rice in each areas. The yield of rough rice was increased remarkably by direct sowing when compared with that produced by transplanting inboth salty areas, but in non-salty area, the former was decreased significantly. There was no significant difference in the yields of rough rice resulting from three seedling methods of direct sowing in each area. The direct sowing method was predominated in number of panicle, weight of panicle, ratio of matured grains, milling recovery percentage, and straw weight in both salty areas, and dicreased in panicle weight and ratio of matured grain in nonsalty area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.698-703
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• 1996

To elucidate the proper nitrogen application method for machine transplanting of rice infant seedling in no-tilled paddy, Dongjinbyeo was used and nitrogen was applied five methods including conventional application method. Leaf color was darker at 80% of total nitrogen was applied as basal and lighter at 20% of total nitrogen was reduced than conventional application method in tillering stage, but wasn't significantly different after panicle formation stage among the application method. And it was thinner at tillering stage and was darker after panicle formation stage in no-tilled paddy compared with tilled paddy. Tiller number, LAI and top dry weight were more at 80% of total nitrogen was ap-plied as basal than conventional application method, and more in tilled paddy than no-tilled one at tillering stage, but at heading stage they were highest at top dressing applied 25 days after transplanting. C.G.R was highest at top dressing for tillering was delayed and it was lower in no-tilled paddy at tillering stage but was higher after panicle formation stage than in tilled one. Yield was highest at top dressing time was delayed among nitrogen application method, but wasn't significantly different between tilled method in same nitrogen application method.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.124-125
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• 2004

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.348-351
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• 2013

Weedy rice is one of the major problems in direct-seeded rice field, resulting in poor rice quality and low grain yield. This study was carried out to evaluate the conversion effect to machine transplanting after wet-direct- seeding for 3 years on weedy rice occurrence, in comparison of repeated wet-direct-seeding. Occurrence of weedy rice in the continuous wet-hill-seeded and broadcasted field for 3 years increased 4 folds, when compared with that in machine transplanted rice paddy. In the first year of wet-direct-seeded field converted from machine transplanting, weedy rice occurrence did not increase, demonstrating lesser weedy rice in wet-hill-seeded than broadcasted field. These results indicate that alternate cultivation of wet-hill-seeding and machine transplanting is more effective to prevent weedy rice occurrence than the repeated wet-direct-seeding method for 3 years.