• Korean Journal of Weed Science
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• v.14 no.2
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• pp.144-155
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• 1994

Scanning electron micrography and Transmission electron micrography studies were performed on the surfaces of stem(coleoptiles) of rice and barnyardgrass under various cropping patterns at 5 days after seeding or transplanting. Stem surfaces of rice under dry condition possessed rodlet-like epicuticular waxes, trichomes, stomata and cork cell layer in both broadcast and drilled rice while barnyardgrass had only thread-like epicuticular waxes, but trichomes, stomata and cork cell layers were not found. However, rice under water condition has no rodlet-like waxes, stomata and cork cells, and barnyardgrass was similar to that under dry condition. On the other hand, those on stems of 8-day and 25-day transplanted rice were well arranged and developed compared with those of direct seeded rice. Electron micrography showed significant difference in thickness of outer epidermal cell walls of rice and barnyardgrass under dry, water and transplanting condition. Thickness of outer epidermal cell was greater in transplanted rice, dry direct seeded rice, water-direct seeded rice and barnyardgrass in descending order.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.229-235
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• 1999

To identify the differences on plant growth and yield of two rice cultivars among direct water-seeding methods broadcasting on flooded paddy surface(BF), drilling on flooded paddy surface(DF), and puddled-soil drill seeding(PD) under markedly different weather condition between 1995 and 1996. The mean air temperature for duration from May to June, early growth stage of rice in 1995 was lower $1{\sim}3^{\circ}C$ than that in normal or 1996. In 1995 the respiratory consumption index during panicle formation stage and early ripening stage was higher than those of in 1996 or normal year. Number of seedling stand among the methods of direct seeding rice appeared slightly higher in order of BF>DF>PD. Properly in Nonganbyeo, the number of seedling stand was much low in 1995 compared with in 1996. The leaf area index and shoot dry weight at early growth stage of rice plant and culm length at mature in 1995 were larger in direct water seeding rice than those of machanical transplanting rice, but in 1996. Faster ripening speed and shorter ripening period of rice crop appeared in 1996 compared to in 1995. It was due to higher growing degree-days, sunshine hours and solar radiation during rice growing season in 1996. Dongjinbyeo rice showed higher yield than Nonganbyeo which had lower ripened grains especially in 1995.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.226-231
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• 1994

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.10a
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• pp.40-41
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• 1991

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.50-51
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• 1988

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.372-373
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• 2012

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.54-54
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• 2018

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.223-229
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• 1992

Very recently, the cultural pattern of paddy rice in Korea was transitted in a short period, and resulted as earlier in season and more in fertillizer application among others. Specially the weed emergence in paddy fields was drastically increased as affected by change of cultural pattern into early planting and into direct seeding methods. Of course, the direct-seeding in row seeding induced more weeds than in broad-cast direct -seeding. By maintaining the water level with saturation of the paddy surface induced more weeds, relatively more annual weeds than by deep in water level, respectively. Relatively more annuals in number of species and in emerged quantity comparing with perennials was caused by the shifting of cultural methods from transplanting to direct seeding. The severe weed competition damages were mainly resulted due to the shading by taller plant heights of weeds than crop during the whole growing seasons. Conclusively, accepting of direct seeding methods in paddy rice culture in Korea, the present bases for weed control methods ought to be naturally and effectively improved to meet the newly made weed problems.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.185-190
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• 2003

This study was conducted to examine rice growth duration by analyzing agricultural climatic conditions at different latitudes in unified Korea. The climatic conditions of nine sites from Wunggi (latitude 42N) to Jeju (latitude 31N) were examined in this study. The rice growth duration of various cropping patterns was determined by analyzing consecutive days when effective daily mean air temperature was suitable for rice growth from the first seeding date to the last maturing date. The rice growth duration in Wunggi located in North Korea was available 138 days for machine transplanting, 115 days for direct seeding on dry paddy cultivation, and 97 days for direct seeding on a flooded surface with cultivation after seeding. On the other hand, the rice growth duration in Kwangju (latitude 35N) located in South Korea was 195 days for machine transplanting, 180 days for direct seeding on dry paddy cultivation, and 170 days for direct seeding on a flooded surface cultivation after seeding.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.503-515
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• 2012

${\alpha},{\beta}$-Dichlorosuccinic acid was synthesized through the reaction of maleic anhydride with $Cl_2$(g) and ultra violet(200~300nm) wavelength in the presence of $CCl_4$. The second reaction of N-(${\alpha},{\beta}$-dichloro)succinic acid contained glucosamine derivatives(I) was accomplished by a modification of the general acylation using excess ${\alpha},{\beta}$-dichlorosuccinic anhydride in the presence of 2% acetic acid with methanol as a solvent at elevated temperature($70^{\circ}C$). We considered organic acid derivatives were useful especially of treatment for the cultivating porphyra and skin beauty culture.