• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.282-292
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• 2015

Seeds of colored rice generally have high anthocyanin and flavonoid content but some cultivars have low seed germination rate. This defect poses unstable seedling establishment in nursery bed. The seed gravity variations of 10 colored rice varieties and its effect on germination, seed soaking duration and their optimum seeding rates for seedling raising in machine transplanting were investigated in the experiment. Based on seed gravity distribution of the 7 black- and 3 red-colored rice varieties at three levels of seed gravity (1.0<, 1.0~1.06, 1.06>), the black colored seeds such as Josaengheugchal and Sinmyungheugchal had high amount of specific gravity of below 1.0 ranging from 86~ 96%, while they had only 3~13% of seeds in specific gravity above 1.06. Sintoheugmi, Heugjinju, Heugnam, Heugkwang had various mass of seeds, showing 29~44% for specific gravity of below 1.0, 24~39% for 1.0~1.06 and 25~45% for above 1.06. On the other hand, the red colored rice such as Hongjinju, Jeogjinju and Geonkanghongmi had high percentage of specific gravity of above 1.06 with 84~86% while they had only 9~12% of specific gravity below 1.0 similar to Ilmibyeo of noncolored rice. The black colored seed generally showed low germination percentage, slow germination speed and long mean germination time, and low water absorption rate as compared with seed of the red colored rice which was similar to those of Ilmibyeo used as a control cultivar. The black colored seeds took 2~4 days longer seed soaking duration than the red colored rice before germination. This was related to high seed amount of specific gravity below 1.0 in black colored rices. The high amount of seed gravity above 1.06 in the colored rice seeds was positively correlated with percentage of germination, germination speed and mean germination time, ripened grain ratio and water absorption. Seed gravity distribution effect were less pronounced between back- and red- colored seeds in seedling emergence. The black colored rice has slightly lower normal seedling emergence rate than the red colored rice and Ilmibyeo in the seedbed soil due to high percentage of ungerminated seed. Normal seedling emergence rate of the black colored rice in the seedbed was 75.2~82.2% for 10-day old seedling and 85.3~ 90.9% for 30-day old seedling which was lower by 4.5~ 8.0% and 0~3.3%, respectively, than the red colored rice. Based on the normal seedling number per tray of Ilmibyeo for seeding rate of 10-day and 30-day old seedlings, the recommended seeding rate of black colored rice is 200~ 220g seeds for the 10-day old seedling and 110~130g for the 30-day old seedling in transplanting rice while the seeding rate of the red colored rice was 220g seeds for the 10-day old seedling and 130g for the 30-day old seedling.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.131-136
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• 2005

This study was conducted from March 21 to July 7 in 2004 at JeJu Island to investigate the influences of seed-ing rates (4, 6, 5, 10 and 12 kg/10a) on creeping bentgrass vegetation. The result obtained were summarized as follows; plant height was getting longer as seeding rate increased from 4 to 12 kg/10a, Although it was no significance from 10 to 12 kg/10a. Root length, Minolta SPAD-502 chlorophyll reading value, leave and root weight increased as the plant height increased. The degree of land cover and density of creeping bentgrass also increased as seeding rate increased from 4 to 12 kg/10a, and the degree of land cover and density of weed decreased. The number of weed species on decreased as increasing of seeding rate. Then ranking of the dominant weeds were Digitaria adscendens, Chenopodium album var. centrorubrum md Poa annua (at 4 kg/10a seeding rate), Digitaria adscendens, Chenopodium album var. centrorubrum and Stellaria media (at 6 kg/10a seeding rate). Chenopdium album var. centrorubrum, Poa annua and Digitaria adscendens (at 8 kg/10a seeding rate), Digitaria adscendens, Chenopdium album var. centrorubrum and Steilaria media (at 10 kg/10a seeding rate), Chenopdium album var. centrorubrum, Digitaria adscendens and Stellaria media (at 12 kg/10a seeding rate). These results showed that the optimum seed-ing rate is 10 kg/10a for growth of creeping bentgrass in volcanic ash soils of Juju island.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.133-138
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• 1981

Effect of the seeding rate and nursery period on the growth and characteristics of seedling suitable for rice transplanter was analyzed and the following results were obtained. The optimum seeding rate were about 100 to 150g in the 30 day old seedling, and 150g per nursery box in the 25day old seedling, respectively, as having adequate leaf number, plant height, dry weight, hardiness and crop growth rate for transplanting. Excessively low and high seeding rate resulted in excessive aging and weakness of the seedling at the later growth stages.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.29-35
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• 2022

Elsholtzia byeonsanensis is a Korean native plant of the Lamiaceae family, and was first introduced in the Korean Journal of Plant Taxonomy. This plant has a short plant length of 20-35 cm, with leathery and glossy leaves. The purple flowers bloom in November, so they are highly useful as potted or ground cover ornamental plants. In this study, tray cell size (128, 162, and 200-cell trays), soil composition [horticultural soil (HS): decomposed granite (DG) 1:1, 1:2, and 1:4 (v:v)], seeding rate (1, 2, and 3 seeds per cell) and additional fertilizer concentrations (0, 250, 500, and 1000 mg/L Hyponex) were tested to find out the optimum seedling growth conditions. As a result of the study, E. byeonsanensis growth increased proportionally as the cell size of the tray increased. The growth was inhibited as the percentage of DG increased. As for the growth according to the seeding rate, plant height, plant width, leaf length, and leaf width decreased as the seeding rate increased, but there was no difference in the number of leaves, stem diameter, and root length. There was an increasing trend in seedling growth as the additional fertilizer concentration increased. Therefore, for producing E. byeonsanensis seedling, it is most effective to fill HS or HS:DG 1:1 in 128-cell trays, sow one seed per cell, and spray the seedling at 1000 mg/L for additional fertilizer.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.200-201
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.05a
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• pp.68-69
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• 1996

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.10a
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• pp.78-79
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• 1995

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.66-70
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• 1998

Four introduced forage rape (Brassica napus) cultivars, 'Akela', 'Ramon', 'Sparta', and 'Velox' and a leading rapeseed cultivar, 'Hallayuchae' were grown at nitrogen (N) rates of 0, 100, 250, 300, 350, and 400 kg/ha to (i) select forage rape cultivars adapted best to Cheju area, and (ii) determine the optimum N rate for the best cultivars. Days from seeding to flowering across the cultivars increased 190 to 195 days as N rate increased from 0 to 400 kg/ha. Average days to flowering of six cultivars ranged from 182 to 198 days. Plant height increased as N rate increased up to 300 kg/ha and then decreased with a further increase in N rate and ranged from 159 to 174 cm among the cultivars. The optimum N rate for the greatest dry matter yield of five cultivars ranged from 222 to 258 kg/ha. Sparta showed the greatest dry matter yield (35.79 Mg/ha), followed by Akela, Hallayuchae, Velox, and Ramon. As N rate increased, crude protein content linearly increased but crude fiber content declined curvilinearly. Akela and Sparta had higher protein content than the other cultivars did. The forage cultivars had lower crude fiber content than the oilseed cultivar Hallayuchae did. Our results demonstrated that Sparta was best adapted to Cheju area and the optimum N rate for Sparta was about 220kg/ha.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.89-97
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• 2020

This experiment was conducted at Sancheong from 2013 to 2015. The objective of this study was to establish the seeding rate, and to clarify the optimum nitrogen fertilizer level for rye seed production in the southern area of Korea. We employed Korean rye cultivar 'Gogu' in this test. The experimental design was a split-plot design with three replications. A split-plot design was used with three seeding levels (3, 5, and 7 kg 10 a^-1) on the main plots and other treatments fully randomized in sub-plots. A factorial arrangement of treatments included three different nitrogen fertilizer levels (0, 3, 6, and 9 kg 10 a^-1). The grain yields of rye affected by increasing the seeding rate. The number of spike per m² and immature grain weight was increasing, while the fertility rate and the number of grain per spike were decreased as seeding rate were increased from 3 kg 10 a^-1 to 7 kg 10 a^-1. The percentage of a productive tiller, 1-liter weight, and 1000-grain weight also decrease by increasing seeding but the grain yields of rye had less effect. There was an increase in the number of spike per m², the number of grain per spike, and grain yields as nitrogen fertilizer level was increased from 0 kg 10 a^-1 to 9 kg 10 a^-1 and followed a delaying heading and an increasing lodging of the plant. But grain yields did not affected by the interaction of seeding rate × nitrogen fertilizer levels. The best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and 3 kg 10 a^-1, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.