• Proceedings of the Korean Society of Crop Science Conference
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• 2005.04a
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• pp.110-111
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.05a
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• pp.54-55
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• 1995

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.05a
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• pp.58-59
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• 1997

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.279-282
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• 2002

Oryzalexine A, a potent growth inhibitor against several weeds such as Digitaria sanguinalis (L) Scop., and Amaranthus lividus L. was purified by conventional solvent partitioning and column chromatographies. This substance showed strong inhibitory activity on several weeds: Germination of seeds of Poa annua L. was inhibited by 36.5 % at 1.0 mM and Amaranthus lividus L. by 56.1% at 2.5mM. Growth of root and shoot of Digitaria sanguinalis (L.) Scop. by 10.2% and 22.4% at 2.5mM, respectively. These suggest that Oryzalexine A in rice straw might affect the germination and growth of susceptible weeds and other plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.14-19
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• 1980

The growth of rice variety 'Suweon 258' that is remote crossed variety between Indica and Japonica rice tended to be influenced more by air temperature than water temperature compared to Japonica variety 'Jinheung' that was influenced more by water temperature than air temperature during maximum tillering stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.453-457
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• 1994

Six local strains collected in Korea and one cultivar (Samdo) introduced from Japan were applied for comparative cultivation to investigate growth characteristics, root yield potentials and saikosaponin contents of root in Bupleurum falcatum L. The one and two year old plants of the native local strains flowered in August 2~3 and July 16~18, respectively, whereas Samdo was late flowering type, being delayed by 18~32days and sustained the growth of above ground parts to the end of November. All the native local strains have similiar characteristics but Samdo was completely different in plant and root type. Local strain collected from Chunchon showed better in growth and root characteristics, consequently resulting high yield of dry roots and saikosaponin contents in both one and two year old plants. The average yield of two year cultivation system was 2.6 times high as 105Kg /10a, compared with that of one year.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.48-51
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• 1977

In order to find out the effects of light quality on seedling growth. 6 rice varieties were grown under the 7 different films for 30 days. Under the blue films (PVC-B20 and PVC-UVC 400-B15), chlorophyll content and nitrogen concentration were higher than those under the other films. Plant height and third leaf sheath growth were suppressed under the blue films, while stimulated under the red film.

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.38-39
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• 1986

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.84-88
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• 2001

Two methods of nitrogen application at the 4th leaf stage were evaluated in direct-seeding rice cultivation on dry paddy soil: one was the top dressing of nitrogen on dry paddy condition before irrigation (TNDP) for labor saving, and the other was the top dressing of nitrogen on dry paddy with mechanical rotavation of the inter-row space (TNDPIR) for increasing the efficiency of nitrogen. To evaluate these two application methods, leaf chlorophyll contents, growth characteristics and yields were compared with two conventional methods, basal application (BA) and top dressing on flooded paddy condition at the 4th leaf stage (TNFP). The SPAD value of rice in TNDP was similar with that in TNFP throughout the whole growth stage of rice. Also, there were no differences in rice growth and yield between the two methods. However, in TNDPIR, the SPAD value was the highest during tillering stage among the four application methods, and the tiller number, LAI at heading stage and the panicle number were higher than the two conventional methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.