• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.146-156
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• 1988

This study was carried out to investigate the change of endosperm substance and seedling growth in rice seedlings for machine transplanting with use of two rice varieties, which Samgangbyeo (Indica${\times}$Japonica) and Dogjinbyeo (Japonica) were sown on May 8 with five levels of seeding density. 1. The total dry matter weight, leaf area, length of the longest root, number and length of new roots were negatively correlated with seeding density, and the plant height had the similar tendency to them from 20 days after sowing(DAS). 2. The rooting ability was negatively correlated with seeding density and decreased from 35 DAS in Dongjinbyeo. 3. The endosperm substance were exhausted at 25 to 30 DAS in Samgangbyeo and at 25 DAS in Dongjinbyeo. 4. The leaf area was more useful than the ratio of plant height to dry matter weight for judging the constitution of seedlings. 5. The reducing sugar contents in the endosperm were the greatest among parts of rice seedlings followed by leaf and root. The contents in leaf, root and endosperm reached maximal at 10 DAS, and varied with plant parts, seedling growth and varieties in different levels of seeding density. 6. The protein contents in leaf and root of rice seedlings became decreased with seedling growth., and were minimal values at 15 DAS. The content in endosperm was decreased soon after seeding, and minimal at 4 DAS with showing some fluctuation of protein content after then.

• Korean Journal of Weed Science
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• v.8 no.1
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• pp.23-27
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• 1988

This experiment was conducted to determine germination ability, life cycle, regrowth ability of Portulaca oleracea L. The newly harvested seeds from P. oleracea flowered before July 15 were able to germinate, but percent germination decreased markedly as the flowering time was later than July 15, showing no germination of seed collected at Sept. 12 which were flowered at August 30, 76.5% of seeds can be germinated in the light as seed stored in room condition for 90 days, but in dark condition, it needed 2 years of seed storage for germination. Low temperature treatment at $2^{\circ}C$ for 5 days enhanced seed germination of P. oleracea in both light and dark conditions. The maximum vagetative growth was observed at 30 to 75 days after seeding. The late seeding time such as July 1 shortened the period of vegetative growth. However, regardless of the seeding times, the first flowering was observed at about 40 days after seeding. Leaf numbers, shoot lengths, fresh and dry weights were greatly affected by the seeding dates, showing that the earlier seedings produced significantly higher shoot length, fresh and dry weight, leaf numbers and branch numbers than those of the late seedings. When all branches were removed on 68 days after seeding, their regrowth ability was 50.3% and cuttaged branches showed 78.1% regrowth as compared to intact plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.8-13
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• 2010

Seedling establishment, overwintering ability and dry matter production of Chinese milk vetch (Astragalus sinicus L. CMV) in natural reseeding practice were compared with the annual seedling in 2006~2007 and 2007~2008. In natural reseeding, CMV seeds were distributed up to 15 cm soil depth in autumn after rice harvest and the seeds generally emerged from soil at less than 5 cm depth while they all emerged from soil surface in the annual seeding. It took 7-8 d longer in seedling establishment of the natural reseeding practice than the annual seeding. Generally, the natural reseeding practice showed higher seedling stand than the annual seeding because of high seedling survival rate. The high seedling survival rate in natural reseeded plant was attributed to the longer root length than that of the annual-seeded plant. In annual seeding, most of the seeds emerged from the soil surface and the root can not easily penetrate the soil while, in natural reseeding technology, the seeds incorporated into the soil during land preparation emerged from the soil at 0 to 5 cm depths, thereby having longer root length. The long root length contributed to greater ability to survive even under low temperature and low soil moisture conditions during winter. The dry matter production in the natural reseeding practice was also higher than the annual seeding when the temperature is low and soil moisture is not sufficient. This result indicates that natural reseeding technology is more stable and beneficial in seedling establishment and dry matter production as compared with the annual seeding especially under unfavorable environmental condition for CMV growth. This practice could be encouraged in CMV-rice cropping system in the southern parts of Korea.

• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.74-75
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• 1991

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.76-77
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• 1991

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.2
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• pp.162-166
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• 1985

• Proceedings of the Korean Society of Crop Science Conference
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• 1994.06a
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• pp.76-77
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• 1994

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.05a
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• pp.46-47
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• 1995

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.90-91
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• 1992