• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.522-527
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• 1997

To find out the optimum seeding rate in corrugated water seeded rice, field experiment was carried out at Yeongdeog Substation of the National Yeongnam Agricultural Experiment Station for two years, 1994 and 1995. A rice cultivar Donghaebyeo, was seeded on May 15 with five seeding rate from 3kg /10a to 7kg /10a. The number of seedling stand per unit area was curvilinearly increased with seeding rate. In characteristics of rice plant associated with lodging, the plant height, fresh weight per tiller, Culm wall thickness and ratio of gravity center were not significantly different among seeding rates, but the breaking strength of 4th internode was slightly decreased with increasing seeding rate and thus, lodging index was generally greater at higher seeding rate than lower seeding rate. Field lodging was observed at 1~3 degree in seeding rate of 5~7kg /10a. Panicle number per unit area was generally increase with increase of seeding rate, while ratio of ripened grain was decreased with increase of spikelet number. Milled rice yield was curvilinearly increased with seeding rate. The optimum seeding rate in the highest rice yield was 4.8kg /10a in 1994, and 4.3kg /a in 1995, respectively.

• 농업기술회보
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• v.42 no.1 s.495
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• pp.40-43
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• 2005

• Agrochemical news magazine
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• v.17 no.2 s.131
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• pp.24-27
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• 1996

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.312-318
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• 1995

To investigate the effect of N split application on the increasing ratio of yield and the yield of rice, urea and slow-releasing complex for sideband placement of fertilizer were applied in Jeonbuk series of Honam plain area. Increasing ratio of yield by N split application was higher in puddled drill seeding (PDS) than flooded direct seeding surface (FDSS) under split application of 40-0-30-30% and 70-0-0-30% at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. It was also higher in LCU application of 70 % of total urea amount than urea application but was not different between two methods of seeding in urea application. Nitrogen ratio transfered to rough grain of rice was higher in FDSS than PDS, errespective of methed of split application, except for the split application of 0, 40, 30 and 30% N fertilizer at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. Nitrogen amount outflowed by artificial drainage for paddy field drying in a day after application of fertilizer was 1,134g/10a in PDS. $NH_4-N$ incerased higher in PDS than FDSS under split application of urea, while was versa under LCU application.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.1-11
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• 1998

This experiment was conducted to investigate weed infestation and to determine effective weed control methods in direct-seeded rice. Twenty two weed species occurred in dry- and water-seeded rice, which was mainly composed of annual weeds. Dominant weed species in dry-seeded rice were Cyperus difformis, Echinochloa crus-galli, Aneilema keisak and Digitaria sanguinalis in discending order. Dominant weed species in water-seeded lice were E. crus-galli, C. difformis, Monochoria vaginalis and Scirpus juncoides. E. crus-galli emerged at 7 days after sowing. In water-seeded rice, E. crus-galli emerged at 5 days after sowing, and M vaginalis, S. juncoides and C. difformis at 8~10 days after sowing. Mean days to emerge important weeds was 20 days in dry-seeded rice and 13 days in water-seeded rice. Leaf development of weeds was faster than that of rice in dry-seeded rice. In water-seeded rice, E eras-galli was more vigorous than rice, but leaf development of other weeds were slower than that of rice. Changes in number of weeds and dry weight oil weed species varied depending upon weed species in the direct-seeded rice. Dry weight of weeds were increased greatly from 30 days to 60 days after sowing in dry-seeded rice. Number of weeds tended to increase up to 40 days after sowing drastically, and then trend of the increase was dull thereafter. Dry weight and number of weeds increased up to 20~60 days after sowing in water-seeded rice. Most effective herbicide treatments was foliar application of cyhalofop/bentazon at 20 days after sowing followed by fenoxaprop/bentazon at 45 days after sowing in dry-seeded rice. All herbicide treatments except foliar applications were very effective to control weeds in water-seeded rice. Slight phytotoxicity was observed in foliar applied fenoxaprop/bentazon at 45 days after sowing in water-seeded rice, but it did not affect rice yield.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.214-220
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• 1989

The experiments were conducted to evaluate safening effect of fenclorim (CGA 123'407, 4,6-dichloro-2-phenyl pyrimidine) against injuries of pretilachlor, butachlor, and benthiocarb in direct-seeded rice under flooded conditions. Pretilachlor and butachlor and benthiocarb reduced crop standing and inhibited growth of rice plants. However, premixture application of pretilachlor, butachlor or benthiocarb with fenclorim at 10-30 g ai/10a greatly reduced rice injury caused by the application of each herbicide alone and thus increased crop standing plant height and dry weight of rice plants compared to herbicide treatments alone.

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.16-17
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• 1986

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.541-549
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• 1992

Lodging and rainfalls during ripening periods and ripening patterns were studied by the different maturing varieties and different seeding dates in labour saving-direct seeding cultivation of rice. Period of emergency in earlier seeding plot was longer than later seeding plot and standing seedlings per unit area and rate of standing seedlings were more and high by the later seeding date. Number of panicles per unit area was decreased by the later seeding dates. On the other hand, the rate of effective tillers was lowest at later seeding plot. Days from seeding to flowering were shortened by the later seeding dates due to the increase of daily growth temperature and reduce of day length. There was much rainfalls during ripening period of early maturing varietal group, however not much rainfalls during ripening period of medium and late maturing varietal groups. The degree of lodging at field was severer by the amount of rainfalls during ripening period. Earlier seeding plots and earlier maturing varietal groups. of used varieties were revealed heavier lodging compared to later seeding plots and later maturing varietal groups. Yield and yield related characteristics were high and good by the earlier seeding dates, especially ripening rate was clear.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.722-728
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• 1997

This experiment was conducted to establish the cultural practice for reduction of lodging by the effective water management under direct seeding on flooded paddy surface as treated by the drainage times using Dongjinbyeo at National Honam Agricultural Experiment Station during 1994-1995. As the increased midsummer drainage times, the field lodging were reduced by reduction of culm length and large amounts of root with favorable distribution in deep soil, indicating low canopy architecture could promote the light transmission in the plants and favorable root growth. The yield performance was high by increased drainage times which contributed to mainly percentage of ripened grain and 1, 000-grain weight. As a result, two to three times midsummer drainage as effective water management during plant growth was desirable.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.402-406
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• 1996

Pythium 5종, 16균주를 공시하여 담수직파한 벼에 대한 병원성을 CMA 배지와 growth chamber 검정법에 의하여 검정한 결과 P. arrhenomanes 1398 균주가 가장 강한 병원성을 보였으며, 다음은 균주에 따라 차이가 있었으나 P. irregulare와 P. spinosum도 병원성이 강하였으며, P. dissotocum과 P. catenulatum의 균주는 병원성이 약하거나 없엇다. CMA 배지 검정때 P. arrhenomanes 1398 균주의 병원성은 주.dirks 2$0^{\circ}C$ 또는 3$0^{\circ}C$의 항온처리보다 주간 3$0^{\circ}C$, dirks 2$0^{\circ}C$의 변온 처리에서 높았다. Growth chamber 검정법으로 병원성을 검정할 때에는 벼알접종원을 이용하는 것이 효과적이었다.