• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.271-276
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• 2003

A Jeju local variety of Italian millet (Setaria italica Beauvois) was grown at five seeding rates (6, 9, 12, 15 and 15 kg/ha) from May 1 to August 25, 2003 at Jeju to determine influence of seeding rate on agronomic characters, forage yield and quality. Days to flowering increased from 89 to 96 days as seeding rate increased from 6 to 18 kg/ha. The plant height increased from 128 to 148cm as seeding rate was increased from 6 to 12 kg/ha and then decreased to 131cm at a rate of 18 kg/ha. With increasing seeding rate, stem diameter, number of leaves, number of nodes, leaf width and weight per plant decreased but leaf length had the same trend with plant height. As seeding rate increased from 6 to 12 kg/ha, fresh furage, dry matter, crude protein, and total digestible nutrients (TDN) yield increased from 35.93 to 54.83 MT/ha, 10.49 to 17.43 MT/ha, 0.94 to 1.79 MT/ha and 5.33 to 9.27 MT/ha, respectively, and then decreased with further increased seeding rates. Crude protein, either extract, nitrogen free extract, and TDN content increased 9.0 to 12.01％, 1.3 to 1.8%, 45.6 to 47.8% and 50.8 to 55.0%, respectively, but crude fiber content decreased 35.2 to 30.0% and crude ash declined 5.8 to 8.4% as seeding rate increased from f to 18 kg/ha. The optimum seeding rate to obtain the highest forage yield was estimated to be 12 kg/ha.

• Journal of Practical Agriculture & Fisheries Research
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• v.9 no.1
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• pp.91-104
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• 2007

The special project was conducted at the cooperative farm where located at Yakjeon-ri Sukcheon-gun Pyeongannam-do, the Democratic People's Republic of Korea. This farm was firstly introduced a newly developed technology-"Bokto seeding technology" for rice cultivation from the Republic of Korea. Total acreage of rice paddy field cultivated by this technology was 800ha and the average yield was 7.17t/ha with paddy rice which was higher by 109.2% than that of the transplanting method for rice cultivation. In general rice disease was decreased at the Bokto seeded rice plant compared to the transplanted rice plant and root activity was higher in Bokto seeded rice. Optimum seeding amount was determined at rate of 90kg/ha in Pyeongdo 5(early ripening variety) and 110kg/ha at Pyeongdo 11(medium ripening variety) and Pyeongyang 43(late ripening variety), respectively. A recommended sowing time was within late April for late ripening variety like Pyeongyang 43, May 1-5 for medium ripening variety, and May 5-15 for early ripening variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.320-327
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• 1990

Experiments were conducted to investigate the method to raise seedling establishment rate and the optimum seeding dates and rates in direct seeding culture using transplanter under submerged field condition in Chuncheon area during 1986 to 1988. Direct seeding on submerged field using transplanting machine after sowing on seedling growing box contained with paddy or upland soil was possible. Higher rate of seedling establishment was obtained in case of sowing sprouted seed and intermittent irrigation after sowing. Seedling establishment rate was higher both in April 30 or May 10 seeding plot. Minimum daily average air and soil temperature to ensure more than 70 percent seedling establishment was 14.8$^{\circ}C$ and 16.3$^{\circ}C$ respectively. Optimum sowing date in the direct sowing was early May and optimum sowing rate was 200g per box, 6kg per l0a. In this case rice grain yield was 481kg per l0a and this is almost same yield level compared hand and machine transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.236-242
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• 1999

To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH$_4$$^{+}$ -N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m$^2$ were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.470-476
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• 1986

In order to find out the optimum seeding date of Job's tears, this study was investigated ecological characters, yield components and yield of Jang Seong native variety at 6 seeding dates (March 20, March 30, April 10, April 20, April 30 and May 10). Emergence period and heading period were shortened as the seeding date was late, and the number of leaves on the main stem was increased as the seeding date was early. Maturing period was 63-66 days when we seeded in March 20, March 30, April 10 and April 20, and it was delayed 68-77 days when we seeded on April 3$^{\circ}$ and May 10. Culm length was longest in April 10 seeding (it was 186.6 cm), and it grew short in the early and the late seeding, but there was no significant difference among seeding dates. Stem diameter was thickest in April 10, and April 20 seeding, that is, thickened to 10.1 mm, and it was thin in the early and the late seeding. Productive tiller number per hill was increased most in April 10 and April 20 seeding, that is, increased to 6.2, and it was decreased in the early and the late seeding. 100 grain weight was heaviest in April 10 seeding; it was 10.7 g, and it was light in the early and the late seeding. Ripeness rate was highest in April 10 seeding (87.4%), and it was lowest in May 10 seeding (76.3%). Grain yield was highest in April 10 seeding (602.8kg per l0a); therefore this period is regarded as optimum seeding date. C. protein, C. fat, C. fiber and C. starch showed significant difference among seeding dates, and C. protein showed possitive correlation (r =0.9811 **) and C. fiber Negative collelation (r =-0.8937*) with seeding dates.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.179-185
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• 2008

The seeding rates of the vacuum suction nozzle seeders are affected by the jumping height of the seeds on the vibrating seed hopper. This study was performed to investigate the optimum vibration condition of the seed hopper on the vacuum suction nozzle seeder for improving seeding performance. Experiments were carried out to determine the vibration conditions of the seed hopper by air pressure and eccentric weight, and to optimize the seed-pickup performance of each nozzle by suction pressure. As the result with the experiments, the fluctuations of the jumping height of the seeds were showed at amplitude 0.4 mm and frequency 42 Hz, and jumping heights of the seeds were increased as the air pressure increase and the eccentric weight decrease, regardless number of seeds of the hopper. The best seeding rate of the seed hopper was 98% at the 300-seed cell, when the condition of the seed hopper was the suction air pressure of 94.6 kPa-abs., amplitude and frequency of the seed hopper vibration were at 0.57 mm and 43.6 Hz, respectively. The optimum vibrating conditions of the seed hopper were decided into frequency 43.6-43.8 Hz and the amplitudes 0.61-0.62 mm.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.265-272
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• 1988

This experiment was carried to investigate the germination pattern in relation to temperatures and lights, and the emergence pattern in relation to seeding depths, lights and the alpha amylase activity of Youngia sonchifolia, Lactuca indica var. laciniata, Ixeris dentata var. albiflora and Ixeris polycephala. In Y. sonchifolia, the optimum germination temperature was $25^{\circ}C$, the optimum seeding depth to emerge was 0 mm and it could emerge in 0-5mm. In L. indica var. laciniata under cool storage, the optimum germination temperatures were $19^{\circ}C-28^{\circ}C$, the optimum seeding depth was 5mm and it could emerge in 0-20mm. In L. indica var. laciniata under room storage, the optimum germination temperature was $25^{\circ}C$ the optimum seeding depth was 5mm and it could emerge in 0-10mm. In I. dentata emerge was and 0mm and it could emerge in 0-5mm. In I. polycephla, the optimum temperatures were $16^{\circ}C-19^{\circ}C$, the optimum seeding depth to emerge was 0mm and it could emerge in 0-5mm. The alpha amylase activity was lower Y. sonchifolia, L. indica var. laciniata and I. dentata var. abiflora than barley cultivar Dongbor#1. And the increased pattern of alpha amylase activity was likely to it of germination rate.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.160-164
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• 1998

Angelica gigas has been a major medicinal crop in Korea for a long time. This study was to determine optimum seeding time and bolting response by shifting seeding time between November 10, 1993, and August 10, 1994 using promising line, Suwon 2. Days to emergence were similar among seeding times from April 10 to August 10 in Suwon. Seedling duration was shortened 92 days when seeded on July 10 compared with the conventional seeding time of April 10. Productivity of seedling ranging from 0.31 to 0.70cm in diameter was highest of 730 plants per $m^2$ in July 10 seeding. When seeded in July 10, bolting rate was 2.4 percent as compared with 2.6 percent in conventional seeding (April 10). The optimum seeding time was July 10. Seedling quality, survival rate after planting in field, and root yield were greatly influenced by seeding time.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.147-148
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• 1998

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.68-75
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• 1978

Experiments were conducted to find out the optimum seeding rate and amounts of fertilizer application for seedling growth of five for machine transplanting. Number of leaves of seedlings increased as seeding rate decreased, but there was no significant differences in leaf number among fertilizer levels. At a seeding rate higher than 100g/box. number of leaves was less than 4.5, but more than five leaves were developed at a seeding rate of 50g/box.