• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.59-67
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• 1992

The duration of raising seedling of infant rice seedling(IRS) in machine transplanting is 8 to 10 days. This experiment was conducted to investigate the minimum duration of IRS's raising seedling and its method by the combination of several treatments such as plant growth regulator, root-break-seat and temperature. The rice seeds of Hwaseongbyeo was soaked in the solution of metalaxyl for 24 hours at room temperature. Metalaxyl (25% wettable powder), a fungicide, was used in 1, 000 times dilution as a promting substance on the root-mat formation of IRS. The application of fungicide in the nursery soil for the controlling of damping-off and physiologyical seedling rot was omitted due to the metalaxyl seed-soaking treatment. Seeding rate was 220g per seed tray (30$\times$60$\times$3cm). To promote the root-mat formation of IRS, the sheets of polyethylene vinyl and absorptive paper were placed bottom the seed tray. The root-mat formation of IRS was promoted at higher temperature and longer duration of raising seedling. The metalaxyl-treated seeds markedly increased the root length and rooting activity of IRS as compared with the control, thus the root-mat formation was excellent. The absorptive paper with polyethylene vinyl as root-break-seat showed a better root-mat formation compared with control, polyethylene vinyl, alone. The minimum duration of raising seedling of IRS was 5 days after sowing based on the root-mat formation and seedling height under the condition of metalaxyl seed treatment, absorptive paper with polyethylene vinyl as a root-break-seat and the raising seedling temperature 30/2$0^{\circ}C$ (day /night).

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.7-11
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• 2010

This experiment was conducted to investigate the growth inhibition effects caused by continuous cropping soil in peony(Paeonia lactiflora Pallas). The effect of extracts from continuous cropping soil of peony was tested with bio-assay method using callus cells induced from peony filament tissues and seedlings derived from peony zygotic embryos. The cell viability and seedling growth were significantly inhibited by methanol extract in continuous cropping soil. Methanol extract from continuous cropping soil was successively fractionated with solvents such as n-hexane, ethyl acetate, n-butanol and water. The seedling growth was inhibited by ethyl acetate fraction obtained in methanol extract.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.415-422
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• 2001

A seedling pick-up device for vegetable transplanters was developed and its work performance was evaluated at the laboratory. The pick-up device extracts seedlings from a 200-cell tray of seedlings and transfers them to the place where they are to be transplanted into the soil. The device consists of a path generator, pick-up pins and a pin driver. The path generator is a five-bar mechanism comprised of a fixed link, a driving link, a driven link, a connecting link and a slider. The slider is constrained to move along the driven link and a fixed slot of combined straight-line and circular paths. The connecting link joins the driving link and the slider. When the slider moves along the straight-line path of the slot it takes seedlings out from the cell and transfers them to the transplanting hopper when moving along the circular path. A proto-type of the pick-up device was built and tested under the various operational conditions such as age of seedling, approach direction and penetration depth of pins to the cell, holding method of seedling and extracting velocity. The device extracted 30 seedlings per minute with the maximum success ratio of 97% using the seedlings of 23 days old. Some design details were also discussed and suggested to enhance the performance of the device.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.151-156
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• 1998

the phytotoxic effects of volatile substances emitted from the tomato plant (Lycopersicon esculentum) on receptor plants such as Bidens bipinnata, Plantago asiatica, Lactuca sativa, Eragrositis ferruginea and Achyranthes japonica were investigated. Bolatile substances from the leaves inhibited seedling growth of receptor plants in the laboratory tests. The inhibition response varied with the concentration of compounds. To identify the phytotoxic compounds from tomato plant a GC/MS method was employed. Forth compounds, such as trans-2-hexeal, linalool, phenylacetaldehyde, methlsalicylic acid and tetradecanaic acid were identified from the essential oil of tomato plants. The findings suggest that the tomato plant may have allelopathic potential.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.284-290
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• 1993

In order to improve the adaptability of rice transplanter to seeding with different length when transplanting multicropping rice in south China. The seedling separating planting mechanism is resynthesized in the paper. According to the agronomy requirements of seedling's transplanting, optimum motional path of the tip point of planting needle is obtained. by applying the established kinematic model of the separating planting mechanism, the relevant software is compiled. On the basis of the features of the problem, the constrained optimization method is utilized to solve the problem with 24 restrictions. Thus, the optimum structure parameters are obtained to satisfy the path points accurately.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.93-96
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• 1985

This study was conducted to establish the maternal haploid method for the practical breeding of M tabacum using the interspeciflc hybridization between M tabacum and N. aflicana. The frequency of surviving seedling per seed capsule of interspecific hybridization was 4.15. Among them, the frequencies of maternal haploid and hybrid were 1.20 and 2.95, respectively. The chromosome numbers of n=24 for maternal haploid and 2n=47 for hybrid were identified in surviving seedling from interspecific hybridiztion. Except the chromosome number, distinguishable morphological differences of material haploid from hybrid were observed at seedling stage.

• Mycobiology
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• v.30 no.2
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• pp.70-75
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• 2002

The mycelia were directly isolated from eight species of fungal basidiocarps, confirmed to the ectomycorrhiza in the roots from the fields(forestry); Suillus bovinus, Paxillus involutus, Lactarius hysginus, Russula fragilis, Lepista nuda, Lyophyllum shimeji, Tricholoma matsutake, and Russula integra. The mycelia were pure-cultured with several transferring in various agars, and inoculated to the roots of pine(Pinus densiflora) seedling by in vitro method. After ten months growth under artificially aseptic conditions, all pine seedlings inoculated were stimulated at the growth-height, whereas those not inoculated were nearly dead. Also, the ramifications of ectomycorrhizal pine roots formed in the synthetic in vitro systems and were various according to the different mycelia. Synthesis of ectomycorrhiza were clearly confirmed in ten months growth, but not distinguished at this moment. It was clearly proved that the mycelia isolated caused the ectomycorrhizae in the roots of pine seedlings.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.73-80
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• 2023

This study was conducted to analyze changes of irrigation water and soil volumetric water content by irrigation method of field soil in Saemangeum reclaimed tideland. The main test irrigation methods was surface drip irrigation, sprinkler irrigation, and sub drip irrigation. In addition, the correlation between irrigation amounts and crop yield by irrigation method was investigated. For soil volumetric water contents increases by 25%, surface drip irrigation took 1.5 hour, sprinkler irrigation took 2.0 hours, and sub drip irrigation took 3.0 hours. As a result of analyzing the irrigation amounts according to the yield, the surface drip irrigation was 2.66 mm/day in the seedling stages, 3.31 mm/day in the vegetative growth stages, and 5.09 mm/day in the flowering stages. Sprinkler irrigation was 2.90 mm/day in the seedling stages, 3.87 mm/day in the vegetative growth stages, and 7.11 mm/day in the flowering stages. Sub drip irrigation was 2.42 mm/day in the seedling stages, 3.09 mm/day in the vegetative growth stages, and 4.87 mm/day in the flowering stages. It was analyzed that there was a statistically significant difference in irrigation amounts by fresh weight and irrigation method (F=4.002, p=0.022), and irrigation amounts by dry weight and irrigation method (F=3.499 p=0.034). Surface drip irrigation was judged to be more appropriate than sprinkler irrigation or sub drip irrigation for field crops in Saemangeum reclaimed land.

• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.53-60
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• 2000

Seedling characteristics of rice sowed at different sowing date in an automatic facility were studied at different days after sowing (DAS). The objective was to determine the optimum sowing date and age of rice seedlings at three locations in the Kyongbuk Province of Korea viz, Andong, Euisung and Kyongsan. Heigbt and shoot dry weight of rice seedlings increased from 10 to 20 DAS and with a delay in sowing time from April to June. In these intervals shoot dry weight-height ratio decreased. For rice seeded in the last ten days of April, optimum seedling characteristics were attained between 15 to 20 DAS at Andong and Euisong and 15 DAS at Kyongsan. At the three locations, 10-day-seedlings exhibited superior characteristics to 15- and 20-day-seedlings for rice seeded in May and June. Rice seedlings of different ages were transplanted at a paddy field to determine the effect of seedling age on yield potential. The mean yield of 10-day-seedlings was 5% higher than that of 35-day-seedlings raised by the conventional method. The yield of 20-day-seedlings was 9% lower than that of 35-day-seedlings. Varietal differences in seedling characteristics of 13 rice cultivars were evaluated for the seedlings seeded in the automatic facility on June. Ten-day old seedlings ranged in height from 13.3 to 17.5 cm and shoot dry weight from 7.7 to 9.4 mg. Two cultivars, Daesanbyeo and Hwayeongbyeo, exhibited superior seedling traits compared to the remaining 11 cultivars and were, therefore, better adapted to the automatic seedling-raising facility.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.78-83
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• 1982

Seedling blight of sesame (Sesamum indicum L.) is one of the most serious diseases in Korea. This study was performed to control seedling blight in the field where sesame has been cultured for 4 years of Industrial Crop Division at the Crop Experiment Station. The pathogenic fungi of seedling blight which is known Fusarium oxysporum f. vasinfectium and Rhizoctonia solani was inoculated to the wheat media and it was spreaded on the experimental field in the concentration of 109 of wheat media mixed with 10g of fine soil. Seed sterilization was the most effective method for seedling blight control for two year experiment. Seed sterilant Benlate-T was highly effective for con trolling seedling blight with infection rate of 4% and yield of 40.7kg per 10a comparing to the control with infection rate of 96% and grain yield of 6.4kg per l0a, the other chemicals, Busan 30, Vitathiram, Captan showed good effect to control seedling blight, but less effect to the Benlate-T. The spraying treatments on leaf surface 25 days after sowing were not effective to seedling blight.