• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.199-203
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• 1990

Effect of a trial compound fertilizer for raising rice seedling in tray, was tested on varieties of Chucheongbyeo and Taebekbyeo and on soil media pH of 6.4 and 5.4. The trial product increased dry weight, number of leaves, and ratio of dry weight to plant height and decreased damping-off incidence. The soil media pH of 6.4. applied trial product, maintained pH 4.0 to 5.4 for seedling period, but the soil media pH of 5.4 was too lower. The nitrogen uptake by rice seedling in the trial product plot was lower at 15 days after seeding compared to the control of straight fertilizer application, but it was higher and 35 days after seeding, resulting in optimum rice seedlings.

• Current Research on Agriculture and Life Sciences
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• v.23
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• pp.1-8
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• 2005

The purpose of this study was carried out to determine the optimum sowing date and days after sowing (DAS) in automatic facility located at Uiseong of Gyeoungbuk province. The seedling height was rapidly increased with a delay of sowing time from April to May. The 10-day old seedlings with suitable plant height (> l0cm) for machine transplanting in the facility were obtained when the seeds sowed after May 20 at Uiseong in Gyeoungbuk province. The dry weight-height ratio of 10-day old seedlings was significantly decreased when the seeds sowed after June 20, and 15-days old seedlings did after May 10. No. of panicles/hill was reduced with increasing of days after seeding. But there were no significant difference among other yield components such as no. of grains/panicle, ratio of ripened grains, and 1,000 grain weight. The highest grain yield, 748kg/10a, was attained from the 10-day old seedlings transplanted at May 27 in comparision with those of 15-day and 20-day old seedlings. The grain yield of 10-day old seedlings transplanted at June 26 was also higher than that of 15-day old seedlings.

• Korean Journal of Medicinal Crop Science
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• v.3 no.3
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• pp.259-264
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• 1995

This study was carried out to find cultivation condition of peony in Euiseong district from 1994 to 1995. 1. Age distribution in cultivation of peony was from 30's to 50's and cultivated years was mainly from 5 years to 10 years, but there was more than 15 years 2. Cultivating area per house hold were 1300 pyeong average, there were moderate $400{\sim]1000$ pyeong and also those are occupied 22.6% more than 2000 pyeong. 3. The mothods of transplanting in Euiseong peony which Euiseong district was mostly divided peony but Yeongchen district used seedling stock. No. of sprout was mostly $3{\sim}4$ and planting time was mainly from Mid to Late of October. 4. The percentage of sterilization of soil and seedling stock was 77. 4%, in mulching by vinyl in tran­splanting 64. 5% in black vinyl and 25. 8% in white one. 5. Number of plant in peony planting was $3000{\sim}4000$ plant per l0a even more there was more than 8000 plant. 6. Chemical spraying time in peony field was 2 time in $1{\sim}2$ years cultivating, and $3{\sim}4$ time in $3{\sim}4$ years one. 7. Condition of fertilizer application in peony field was 40% in non-application, but $56.7{\sim}76.7%$ in 2 year to 3 years, and the time of fertilizer was mainly 3 time. 8. Drying time peony after havesting was from 12 to 24 hours by briquet stove and 24 hours by ma­chine of hot wind, also dry method of peony was mixed briquet stove and hot wind machine.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.233-236
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• 1984

Studies were conducted to investigate the effect of Carbofuran 3G on the density variation of rice pests and their natural enemies in case the insecticide was treated two times as compared with usual trials in paddy field. Even the two times application of Carbofuran 3G in the nursery boxes of machine transplanting and paddy water trials obtain same results to pests, small brown planthopper (Laodelphax striatllus), green rice leafhopper (Nephotettix cincticeps), brown planthorper (Nilaparvata lugens), white back planthopper (Sogotella furcifera), rice stem bore (Chilo suppressalis), rice stem maggot (Chlorops oryzae), rice thrips (cloethrips oryzae) as compared with usual trials. The density of natural enemies, spiders and egg parasite, Anagrus sp. of planthoppers in the two times application part of Carbofuran 3G increased 2.4 fold as compared with usual trials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.339-347
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• 1994

This experiment was conducted to investigate duck-raising system and the optimum nitrogen fertilization level in duck-raising field. Optimum duck rasing density in rice paddy field was 1, 000~1, 500 heads per ha and ducks could be harvested three times in a year starting from 40 days after mature-seedling machine transplanting. When 1, 000~1, 500 heads per ha of ducks was raised once a year, optimum nitrogen application level was 110kg/ha. In the case of three times in a year, it was 8.8kg/ha. The weed control rate of the duck-raised paddy field was superior(93~96%) to control (89%, treated twice with herbicide).

• Journal of Biosystems Engineering
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• v.30 no.5 s.112
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• pp.261-267
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• 2005

In order to save labor and cost, direct seeding has been considered as an important alternative to the machine transplanting in rice cultivation. As current seeders for direct seeding of rice seeds drill irregular amount of seeds under various operating conditions, conventional drilling should be turned to precision planting which enables accurate placement of proper amount of rice seeds at equal intervals within rows. In this study, design, construction and performance evaluation of a precision seed metering device for planting of rice seeds were carried out. As prototype, the conventional roller type seed metering device was modified for planting: increasing diameter of metering roller, setting 2 or 4 seed cells on metering roller, adding seed discharging lid and its driving cam mechanism. Through performance tests for prototype and the current seed metering device, number of seeds in a hill, planting space and its error ratio, coefficient of variation of planting space (planting accuracy), and seeding length of $90\%$ of seeds in a hill divided by planting space (planting precision) at setting planting spaces of 15, and 20cm, seeding heights of 10, and 20cm, and seeding speeds of 0.1, 0.2, and 0.5m/s were investigated. Prototype showed better seed planting performance than the current seed metering devices. When setting planting space of 15 cm and seeding height of 10cm, prototype with 2 seed cells showed that variations of planting space and seeding lengths of $90\%$ of seeds in a hill at up to seeding speed of 0.5m/s were within 0.9cm, and 3.6cm, respectively.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.225-229
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• 2016

This study was conducted to investigate the herbicidal efficacy of up granule formula of benzobicyclon mixtures, benzobicyclon + azimsulfuron + oxaziclomefone up granule (BAO UG) and benzobicyclon + bensulfuron-methyl + fentrazamide up granule (BBF UG) to control annual and perennial weed species in a rice paddy field. Four annual weed species including Echinochloa crus-galli L. and three perennial weeds were dominated in the experimental field. Application of BAO UG and BBF UG was highly effective to control both annual and perennial weed species. No phytotoxic effect was observed in the rice based on the plant height, the number of tillers, and culm and panicle length. Finally, rice yield in the BAO UG and BBF UG treatment was as much as that in the hand weeding. This study indicates that self-dispersible floating formula of benzobicyclon mixtures can be applied to control both annual and perennial weed species in rice paddy fields and contribute to save labor costs.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1009-1020
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• 1996

Direct-seeded rice can have comparable yield with transplanted rice if its inherent problems can be solved. It is a labor-saving technology and can significantly reduce production cost because seedling nursery , pulling , and transplanting are omitted. Turnaround time between cropping is reduced hence the possibility of a third annual crop. But direct-seeded rice is very vulnerable to pest attack (by birds, rats, and golden snails), desiccation, weed infestation, and prone to lodging resulting to unstable crop establishment and inconsistent yield. These problems can be solved by anaerobic seeding (sowing pre-germinated seeds under the soil). It requires precise seed placement into the soil to optimize its benefits. We developed a four-row anaerobic direct seeder (US $ 200 commercial price) for this purpose . It consist of a structural framework mounted with a drum -hopper metering device, flotation type drivewheels, spring-loaded and adjustable furrow closers, and furrow open rs, and a plastic rainguard. It can sow in line pre-germinated seeds into the soil thus permitting the use of mechanical weeders for a chemical-free weed control. Its performance was comparable with the Japanese two-row anaerobic seeder (costing US$400) in terms of seed placement and crop establishment. It was tested with five cultivars. Seeding rate varied from 38 kg/ha to 80kg/ha. Crop establishment ranged from 64 to 99 percent while grain yield varied from 3.0 t/ha to 5.4t/ha. A six-row anaerobic seeder was also developed and adapted to a powertiller for increased capacity , field efficiency , and easier operation. The anaerobic seeder is useful to farmers shifting to direct seeding to reduce rice production cost and to researchers conducting agronomic studies in direct-seeded rice. Blueprint of the machine is available free of charge from IRRI.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.17-24
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• 2014

The experiment was conducted at the growth chamber to determine germination, seedling growth and fresh weight between the untreated control and iron-coated seeds in germination test of the rice seeds. There was of 95% germination in rice seeds regardless of treatments and days for seedling emergence was relatively 13-14days. Seedling height was 4.9cm of the iron-coated seeds but 0.4cm of the untreated control and there was 6.S roots of seedling in iron-coated seeds and 5.5 roots of seedling in the untreated control, respectively. The fresh weight of seedling was 107mg of the iron-coated seeds and 66mg of the untreated control at 35days after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.273-281
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• 2018

Wet hill seeding (WHS) is one of the more famous labor and money saving methods technology used for rice cultivation. In WHS, rice standing percentage and weedy rice occurrence are the most important factors considered to secure a rice yield. We investigated the optimum seeding date of WHS in the Southern Plain area of South Korea. Weedy rice needed two weeks at $15^{\circ}C$ to show over 80% emergence. Germinated rice seed grown at $20^{\circ}C$ needed over for 10 days to achieve a shoot length over 3 cm. In field cultivation, the mean temperature for ten days after seeding showed a highly positive correlation with rice standing rate, spikelet number per square meter and yield index that favorably compared to machine transplanting. With these data, we suggest that the optimum seeding date of WHS that can secure over 98% of yield index of machine transplanting in Southern part of Korea is May. 21~Jun. 5 in Honam and May. 16~Jun. 5 in Yeongnam area.