• Korean Journal of Weed Science
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• v.17 no.2
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• pp.169-175
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• 1997

The effect of different cultural patterns on the growth and herbicidal response of rice(Oryza sativa L.) and barnyardgrass(Echinochloa crus-galli var. oryzicola) was studied tinder direct-seeded rice and early rice seedling conditions. In dry-seeded rice condition, the growth of rice and barnyardgrass was the greatest in 3cm-seeding depth and 40% soil moisture, respectively. At 10 days after herbicide application, plant height of rice was severely inhibited in 1cm-seeding depth and 50% soil moisture, and the degree of inhibition was severer at application of pendi+molinate EC as compared to that of butachlor EC. On the other hand, plant heigth of barnyardgrass by treatment of herbicides was severely reduced regardless of seeding depth and soil moisture. The lengths of barnyardgrass mesocotyl and rice coleoptile were increased with increasing seeding depth and were severely inhibited by applied herbicides in 1cm-seeding depth under dry-seeded rice condition. The dry weight of rice at different leaching times after herbicides application showed slightly decreasing trend as the leaching time was delayed, but the growth of barnyardgrass was very severely inhibited regardless of the leaching time. In addition, the phytotoxicity of rice showed decreasing trend with the increase in transplanting depth and delay of application time under early rice seedling condition.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.1-8
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• 2001

This experiment was conducted to determine the effect of nursery soils and seeding density on seedling growth characteristics in automatic facility for raising of rice seedlings. The seedling characteristics were evaluated for the 10-day and 15-day old seedlings grown in six different nursery soils including farm-made soils. Two levels of seeding amount, 250 g and 300 g/tray ($60{\times}30{\times}2.5$ cm), were applied to compare the seedling characteristics according to seeding density on different nursery soils. There were wide difference in soil components among the nursery soils tested. In acidity of nursery soils, 'Bunoog 2' was the highest, pH 5.1, and 'Samkyung' was the lowest, pH 8.6. The content of available phosphate was the highest value, 843 ppm, in 'Bunong 1' and the lowest (74 ppm) in farm-made soils. The total nitrogen content of 'Bunong 1, 2, 3' and 'Weonjo' soils was higher than there of 'Samkyung' and farm-made soils. There was no difference in plant height among three types of 'Bunong' soils (Bunong 1, 2, 3), but the seedling height grown in farm-made soils was shorter than there in other nursery soils. The plant heigh was slightly taller as the increase of seeding amount from 250 g to 300 g/tray, and the difference in plant height was larger in 15-day old seedlings as compared with 10-day old seedlings. Dry weight of seedlings grown for 15 days in three 'Bunong' soils was heavier than those in other nursery soils. Based on the growing characteristics of seedlings grown in different nursery soils, the heat result was obtained from a nursery soil, 'Bunoog 2', among six marketing nursery soils tested.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.1-11
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• 1996

The effect of seeding on the thermophilic composting of food waste was investigated with selected strains of yeast, thermophilic bacteria and the mixed strains of yeast and bacteria in the lab-scale composter at $50^{\circ}C$. The results demonstrated that in all case the growth of yeasts preceded the growth of thermophilic bacteria by one or two days. The seeding of bacteria alone was ineffective for thermophilic bacterial development and the rapid increase of total thermophilic bacterial count was obtained by mixed seeding of yeasts and bacteria. Moreover, the bacterial growth was accelerated by the addition of yeasts alone. It was revealed that the yeasts removed organic acids from the food waste at the initial period and consequently induced the growth of thermophilic bacteria. The results presented in this paper indicate the indispensable role of yeasts for thermophilic process of food waste composting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.448-452
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• 2002

The purpose of this study was to determine the optimum sowing amount for raising rice seedlings in automatic facility. four levels of seeding amount, 200, 220, 250 and 300 tray were applied to compare the seedling characteristics according to seeding density. Sowing dates were fixed at May 10 for single cropping and June 10 for double cropping. The seedling height was taller as the increase of sowing amount from 200g to 300g/tray, however the seedling quality was decreased with increasing of seed density. At 40-50 days after transplanting, there was no significant difference in the plant height and tiller number among the rice seedling raised under different seeding densities. Grain yield of 15-day old seedlings transplanted at May 25 was not significantly different among four different levels of seeding amount. However, the yield of 10day old seedling transplanted at June 20 was significantly higher in seeding density of 250g/tray than that of 300g/tray.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.353-355
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• 2000

The seasonal occurrence of aphids was investigated in the soybean Held to increase the control efficiency of aphid vectors of Soybean Mosaic Virus. The patterns of aphids occurrence were different according to planting time. There were two peaks in late June and mid-August in aphid population in optimum seeding (May 20), whereas the peak was around mid-June in early seeding(Apr, 20). Acyrthosiphon solani was dominant Species in early seeding, while Aphis glycines was dominant in optimum seeding. In early seeding, SMV incidence increased rapidly between 20 June and 30 June, suggesting that virus spread was strongly correlated with increased colonization of aphids. Imidacloprid WP, benfuracarb EC and acephate WP showed a good effect for the control of aphids without phytotoxicity. In the plot with infurrow treatment of imidachloprid G until 52 days after shooting, aphids were controled effectively. Acephate WP was applied as a foliar spray at V4, V6, or V4/V6 stage and all the treatments were effective on reducing: SMV incidence.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.143-158
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• 2009

This experiment was carried out to examine ecological response and soybean quality as affected by environmental cultivation for producing high seed quality in domestic soybean variety. The results are as follows: Under equal cumulative temperature condition, soybean plants grown in Muju showed longer days to flowering, which was an effect of the long day-length on high latitudes, and longer duration of reproductive stage as a result of low temperature within that period. Considering apparent seed quality, 100 seed weight of soybeans grown in Muju was heavier than Miryang. Ratio of seed crack and disease-damaged seeds was lower in Muju, and these parameters decreases as planting was delayed. The protein contents did not show significant difference in terms of altitude and planting date, however, crude oil contents were higher in Miryang. An opposite trend was observed in C18:1 and C18:3. In the fatty acid composition, the proportion of C18:1 decreased as seeding date was delayed, and was higher in Miryang. Opposite observations were obtained from C18:3. The anthocyanin contents were highest on June 10 planting and higher in Muju than in Miryang. Isoflavone content was higher as seeding date was delayed and is similar accross seeding dates in Muju. As a summary, for high seed quality production the optimum planting date was June 10, and Muju was more suitable region than Miryang.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.179-185
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• 2008

The seeding rates of the vacuum suction nozzle seeders are affected by the jumping height of the seeds on the vibrating seed hopper. This study was performed to investigate the optimum vibration condition of the seed hopper on the vacuum suction nozzle seeder for improving seeding performance. Experiments were carried out to determine the vibration conditions of the seed hopper by air pressure and eccentric weight, and to optimize the seed-pickup performance of each nozzle by suction pressure. As the result with the experiments, the fluctuations of the jumping height of the seeds were showed at amplitude 0.4 mm and frequency 42 Hz, and jumping heights of the seeds were increased as the air pressure increase and the eccentric weight decrease, regardless number of seeds of the hopper. The best seeding rate of the seed hopper was 98% at the 300-seed cell, when the condition of the seed hopper was the suction air pressure of 94.6 kPa-abs., amplitude and frequency of the seed hopper vibration were at 0.57 mm and 43.6 Hz, respectively. The optimum vibrating conditions of the seed hopper were decided into frequency 43.6-43.8 Hz and the amplitudes 0.61-0.62 mm.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10b
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• pp.46-52
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• 2000

Performance of direct seeded upland field Schizonepeta tenuifolia Briquet in Southern areas of Korea was evaluated at different seeding methods (drilling and broadcasting) and seeding rates (1.5, 2.0, 3.0 and 3.5$\ell$/10a). There were no differences in the yield components such as length of stem and ear diameter of stem number of branch, internode and ear, and yield of fresh and dry stem between the seeding methods with drilling and broadcasting, but yield components such as length of stem and ear, diameter of stem, number of brench, internode and ear, and yield of fresh and dry stem increased with seeding rates of from 2.5$\ell$/10a to 3.5$\ell$/10a. Therefore optimum rates and methods of sowing were from 2.5$\ell$/10a to 3.5$\ell$/10a with seeding at the drilling and broadcasting.

• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.187-198
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• 1995

The objective of this research was to produce sod by box seeding for zoysiagrass or by vegetative propagation for zoysiagrass and manilagrass.1 Various ratio of peatmoss to sand(v /v) were prepared to find idea[ medium for fast and light weight sod production. Then, the days required for sod formation, the effect of growth regulators on the growth of turfgrass, and the various storage methods for winter keeping of sods were also investigated. 1.The mixed medium of sand and peatmoss(v /v, 1 : 2) showed more biomass production than that of sand. 2.In comparison of seeding rate of zoysiagrass, the amount of log /$m^2$ was most effective in the fast and dense sod formation. The amount of 20g /$m^2$ also showed fast sod formation. But, it resulted in weak plant and less tillering. During April to June, about 100 days were required to form sod with seeding rate of 5g /$m^2$ regardless of seeding time. Whereas 80 days were required to form sod in the rate log /$m^2$, which was 20 days shorter than that of 5g /$m^2$. 3.More than 85% of shoots in sod stored in field or plastic house during the winter time resumed the growth in good appearance after transplanting. The whole covering of ground with sod resulted in less weeds and faster formation of lawn. 4.Vegetative propagation of manilagrass showed about 7 to 15 days faster formation of sod than that of zoysiagrass. Application of GA increased shoot growth and BA increased the total number of tillering. However, the effects of the combined application of GA and BA were negligable.

• Journal of Powder Materials
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• v.5 no.2
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• pp.133-138
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• 1998

The effect of $\beta$-$Si_3N_4$ seeding on microstructural development of silicon nitride based materials has been investigated. In particular, to observe more distinctly the abnormal grain growth in pressureless sintering, fine $\alpha$-$Si_3N_4$(mean particle size: 0.26 ${\mu}m$) powder classified by sedimentation method was used. It was possible to prepare silicon nitride with abnormally grown grains under low nitrogen pressure of 1 atm thanks to the heterogeneous nucleation on $Si_3N_4$ seed particles. The size and morphology of silicon nitride grains were strongly influenced by the presence of $\beta$-$Si_3N_4$ seed and overall chemical composition. For specimens with initially low $\beta$-content, the large grains grew without a significant impingement by other large grains. On the contrary, for specimens with initially high $\beta$-content, steric hindrance was effective. The resulting microstructure was less inhomogeneous and characterized by unimodal grain size distribution.