• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.167-173
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• 2002

This experiment was conducted to figure out the change of soil physical properties, rice growth and yield with the years of continuous cultivation in direct dry-seeding and no-tillage machine transplanting. Experiments were conducted at NHAES(National Honam Agricultural Experiment Station, RDA, Iksan, Cheon Buk Province, South Korea) with a rice variety "Dongjinbyeo" from 1995 to 2000. In no-tillage machine transplanting cultivation, organic matter in soil was higher than that on direct dry-seeding and was significantly high in topsoil. Problematic weed species were E. crus-galli B., A. keisak H., and L. japonica M. Plant height and tiller number m-2 were higher in common-tillage during the total growth duration. The highest weedy rice occurrence of 27.5% was observed in live years' continuous direct dry-seeding and followed by 6.2%, in four years', and 3.7%, in three years'. The highest yield reduction of 38% was observed in five years' continuous direct dry-seeding. The reduction may resulted from the competition between weedy rice and cultivated rice.

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.36-43
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• 1993

Differences in community space of weed and rice were investigated among five types of rice (Oryza sativa L.) cultivation. The five types employed were three transplanting cultivations such as conventional hand transplanting, machine transplanting with 30-day-old seedling, and machine transplanting with 10-day-old seedling and two direct-seedlings such as flood direct-seeded rice by pregerminated seed and dry direct-seeded rice by dry seed. The greatest competition between rice and weeds as determined by growth rate of rice was found in between 10 and 11 weeks after transplanting (WAT) and/or seeding, irrespective of cultivation types. Competition injury due to weeds was greater in transplanting with 10-day-old seedling than with 30-day-old seedling. The greatest injury in growth of rice was found in direct-seeded cultivation. In transplanting cultivations space occupation by rice in lower than 80 cm height level was low as compared with that by weeds. Plant heights of dominant weeds such as E. crus-galli and E. kuroguwai were shorter by heading date, but taller after the heading date than those of rice. In direct-seeding community space was mainly occupied by the weeds. The pattern of community structure and competition injury caused by weeds showed a similar tendency obtained on the basis of species distribution, number, and dry weight of the occurred weeds.

• The Korean Journal of Mycology
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• v.34 no.1
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• pp.39-53
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• 2006

This studies investigated the effect of concentrations of sodium chloride (NaCl) on occurrence and growth of fruitbody in oyster mushrooms, Pleurotus spp. Our experiments divided into two parts. When the water contents in substrate were added with sodium chloride solution in cotton waste box cultivation as a first experiment, the growth of mushroom was damaged as the concentration was increased, even though there was a little difference according to the strains. The yield in 1.0% NaCl solution was decreased to 72% compared to non-treated plot while that in 3.0% solution was only 2% of the non-treated plot. Morphological characteristics of mushrooms cultivated in substrate with the different concentration of the solution showed different results. For example, the size and thickness of pilei were not influenced by NaCl concentration, but the length of stipes and individual weight were much influenced. In plastic box cultivation filled with cotton waste, watering treatment with the different concentrations of sodium chloride solution, the second experiment, did not show any difference according to the concentration until 1.0% solution but there was a little difference according to the strains. The productivity of fruitbody started to decrease at 2.0% of the solution and the yield and quality of mushroom in 3.0% solution treatment were generally low. After the second flush, days for mushroom sprouting were generally prolonged in proportion to the solution concentration. Taken altogether, the second experiment did not show a clear effect as the case of the first experiment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.233-249
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• 1976

This experiment was conducted in an attempt to find the variation of growth, yield components and .yield in accordance with different seeding rate and fertilizer level. The degree of yield increase by increased fertilizer level was higher in heavy spike type .than in high tiller type. but that by increased seeding rate was the reverse in barley and wheat. 1, 000 .grains weight and maturity was increased by increased fertilizer level in heavy spike type (Haganemugi and Young Kwang) but decreased in high tiller type (Suweon ＃165 and Yuk Seung＃3).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.187-202
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• 1976

Experiment were conducted to study the photosynthetic ability of several rice varieties and the influence of the drymatter production on the yield components of the rice plant, especially in ripening period. The photosynthetic ability at the ripening period, the varieties were classified into two groups as relatively high capacity and low capacity. With the earlier the transplanting date and the higher the N-content leaf blade, the greater the ratio of reserved assimilates befere heading time to the ear. This could be support the fact that the rate of full-ripened grains or grain yield of 'Tongil' variety may increased by the change of environment condition.condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.13
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• pp.77-81
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• 1973

The experiment was carried out to make clear the root characters and relationships among some quantitative characters of soybeans. The results obtained are summarized as follows: 1. Stem diameter was shown the greater growing in thickness after one month from sowing than the earlier stage, and the greater growing was shown in fertile bed soil than in sand soil. 2. The elongation of plant top in soybean plant was also shown the greater rate in bed soil than in sand soil 3. The length of plant root was longer than the length of plant top in the earlier stage of growing, and the length of root was much greater in sand soil than in fertile bed soil. 4. Weight of plant top was shown more in bed soil than in sand soil, but this tendency was shown more greater rate in the length of plant top than in weight of plant top. 5. Weight of root was more compared with weight of plant top in the earlier stage of growth, and also more greater rate was shown in sand soil than in fertile bed soil. 6. Highly significant correlations were shown among five quantitative characters, namely stem diameter, length of top, weight of top, length of root and weight of root, etc.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.153-160
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• 1969

Experiments on sweet sorghum(sorgo) with different population per unit area were conducted from 1966 to 1968 for the first time in Korea. By increasing plant population stalk weight, refinable sugar and seed weight per plot were increased, but stalk weight per plant, brix percentage, sugar content, stem diameter and 1, 000 seed weight were decreased. Plant height, maturity and lodging were not affected by the treatments. The result obtained has suggested that the effects of plant spacing within row on the characteristics of plant growth and on yields were greater than those of row width. Negative correlations existed between sugar content and sugar yield, and seed weight per plant and seed yield. The optimal plant population in this study ranged from 16, 700 to 22, 200 plants per 10a, row width of 60cm and plant spacing in row of 15 to 20cm resulted in the highest sugar and seed.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.29-40
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• 2000

This experiment was conducted to find appropriate media in hydroponic Culture of Angelica keiskei. The mediaused were carbonized rice hull, perlite, vermiculite, mixture(carbonized rice hull (1) : perlite (1) : peatmoss (1)), mixture+peatmoss20%, mixture+peatmoss40%, mixtrue+peatmoss60%, perlite 40%+peatmoss40%+vermiculite20% and open field cultivation. The highest yield of Angeli ca keiskei was shown 4,428ka/10a at vermiculite. The yield of vermiculite was increased about 133 percent compared to that of open field cultivation. The highest germanium contents was shown 0.52ppm at mixture+peatmoss 40%. The contents of germanium increased about 108 percent at mixture+peatmoss40% compared to that of open field cultivation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.209-214
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• 2006

One hundred Individuals that were collected from plains and mountains all around South Korea were used for this experiment. The inhibition abilities of lipid peroxidation by Artemisia spp. collections were compared with BHT (butylated hydroxytoluene). The results could be confirmed the excellency fur control of lipid peroxide level such as BHT 200 ppm in all mugwort collections. Antioxidant activity (AEAC), electron donating ability (EDA), total phenolic compound, and flavonoids of 100 Artemisia spp. collections were analyzed. Total phenolic compound contents of Artemisia spp. collections were ranged from 156 to 1,767 rng/100 g, and mugwort collections with more than 900 mg/100 g of total phenolic compound content were 20 individuals. Electron donating abilities were ranged from 13.4 to 95.0%, and mugwort collections over 90% of electron donating ability were 23 individuals. Antioxidant activity of ethanol extracts that used ABTS and DPPH radical were measured and mugwort collections with high total phenolic compound contents had high radical exclusion ability as well. Artemisia spp. collections, AC-60, AC-67, AC-77, that showed the high levels of antioxidant activities and had good growth characters and productivity, were selected for mass production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.640-649
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• 1996

This study was conducted to obtain fundamental informations necessary to breed forage sorghum at the field of the Livestock Experiment Station from 1988 to 1991. Heterosis was discussed in crossing groups of sorghum X sweet sorghum, sorghum X sudangrass, and (sorghum X sweet sorghum) X sudangrass. Leaf dry weight and stalk dry weight per plant in sweet sorghum crossing group, stalk dry weight per plant in sorghum X sudangrass crosses and leaf area per plant in three way crosses showed the greatest Heterobeltiosis(H$_{b}$). There were significant differences in plant height, stalk diameter and number of tillers per plant between sweet sorghum and sudangrass crosses. H$_{b}$ for total dry matter yield in sweet sorghum and sudangrass crosses were 45.9% and 95.0%, respectively. On the other hand, heterosis for total dry matter yield in three way crosses was smaller than H$_{b}$. There was no relationship between dry matter yield of parents and heterosis of hybrids in sweetsorghum crosses. However, positive correlations between parental yield and hybrid yields were observed. In sudangrass crosses, there were negative correlations between parental yields and heterosis of hybrids. However, no correlation between parental yields and hybrid yields were observed. In three way crosses, there were no correlations between parental yields and heterosis, and between parental yields and hybrids yields.