• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.445-456
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• 2014

This study was conducted to investigate the kernel characteristics of sweet corn during ripening with different sowing date. Godangok and Guseulok were sown at April 10, July 10, July 20, and July 30 in 2013. Irrespective of sowing date, fresh and dry weight of 100 kernel, starch content, crude fat content, and hardness of sweet corn kernels were significantly increased according to maturation (p<0.05). But moisture content, total sugar content, crude protein content and crude ash content of sweet corn kernels were significantly decreased according to maturation (p<0.05). The changing rates of 100 kernel weight and starch content on kernels were faster at early sowing date than at late sowing date. The moisture content of sweet corn kernels was 68~69% at optimum for harvesting. The degree of sweetness on Godangok was about 1.8 and 1.4 times higher in sowing at July 20 and July 30 than in sowing at April 10. On the other hand, the degree of sweetness was similar regardless of sowing time on Guseulok. These results will be helpful to farmers for fall-harvest sweet corn cultivation and management.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.250-250
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• 2017

Studies were conducted to select the optimum sowing date and planting density of sesame in the middle area of Korea. To select the optimum sowing date, sesame seeds sowed from 20 April to 7 July with 15-day intervals. To select the optimum planting density, sesame seeds investigated under four different planting distances ($30{\times}10,\;30{\times}15,\;30{\times}20$, and $30{\times}25cm$)respectively in the experimental field. As seeding date was delayed, days to emergence were shortened flowering and maturing date were delayed. Delayed sowing date resulted in decreased length, capsule setting stem length and number of capsules, and branchs per plant. Number of Capsules was high sowing date on 5 May in the range of 90~95ea/plant in sesame. Also yield of sesame seeds was most high on 5 May in the range of 142kg/10a by sowing date. Sowing date up to 5 May showed no effect on grain yield, but from 5 June to 5 July decreased 27%, 68% and 86%, respectively. For all planting distances, weight of 1,000 grain was not significantly different. However, number of branches and capsules tended to increase. Number of Capsules was high planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 146.7~165.7ea/plant in the Geonbaekkae. Areumkkae also showed the same tendency on planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 122.0~147.5ea/plant, respectively. Yield of Geonbaekkae and Areumkkae seeds was most high 116kg/10a, 117kg/10a, respectively on planting distance $30{\times}20cm$. Decreased in the planting distance of sesame has increased the incidence of disease and lodging. Based on the results, we suggest a planting distance of $30{\times}20cm$ maximal growth and yield of sesame in the middle area of Korea. Considering growth characteristics, sesame yield ability, the optimum sowing date was 5 May and optimum planting pattern was founded to be two rows planting in one ridge and planting densities was $30{\times}20cm$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.53-60
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• 2022

Recently, Black soybean (Glycine max L. Merr.) is being cultivated in paddy fields instead of rice. However, research related to the effective sowing date is insufficient in paddy fields. This study aimed to identify the sowing date for stable cultivation of black soybean by investigating its yield and seed characteristics in a paddy field. In the study, cultivation experiment with five different sowing dates (May 25, June 10, June 25, July 10, July 25) were conducted in 2019 and 2020. Days from sowing to flowering can be shortened by delaying the sowing date. In the present study, the yield of black soybean in paddy fields was the highest with June 10 as the sowing date and was calculated as 224 kg·10a^-1 and 200 kg·10a^-1 in 2019 and 2020, respectively. However, the highest values of seed coat cracking was 51.1±5.1% and that of total anthocyanin contents was the 3.99±0.72 mg/g, both of which were observed in 2020 for the experiment with May 25 as the sowing date. Regression analysis showed a positive correlation (R²=0.9312) between soil water contents and seed coat cracking rate during the flowering period. Hence, the soil water contents during the flowering period would have a negative effect on the seed coat development.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.31-37
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• 1986

In order to study the possibility of grassland improvement by spring sowing in the forest, microenvironmental conditions, emergence, percentage of grasses and weeds, root weight and dry matter yield of grasses were investigated. Two field sites (forest grassland and full-sunlight grassland) and two sowing times (March 20 and April 10) were assigned. The condition of the forest grassland was area of pine trees with 50% shading, and the experiment was performed at the Livestock Experiment Station in Suweon, 1984. The results obtained are summarized as follows: 1. For germination and early growth of grasses, full-sunlight grassland was more advantageous than forest grassland. Growth after that stage, on the other hand, forest grassland was more suitable. Especially, during dry and high temperature season, temperature of soil surface and underground in the forest grassland were decreased by $6-7^{\circ}C$ and $3-4^{\circ}C$ each other, compared with those of the full-sunlight grassland. Also soil moisture content was continuously higher in the forest grassland. 2. At March 20 sowing the emergence time in the full-sunlight grassland was shortened by 8 days, compared with that of the forest grassland. In case of sowing on April 10, however, there was no difference between two grassland sites. 3. Grasses grown in the forest was more prostrate and leaves from them decayed more, compared with those of the full-sunlight grassland. 4. The percentage of grasses in the forest grassland was 80 to 85 %, on the other hand, that of the full-sunlight grassland was only 15 to 20 %. And the percentage of grasses tended to be high in the plot of early sowing time. 5. Dry root weight and root length of grasses grown in the forest were inferior to those of the full-sunlight grassland (P<0.05), but there was no significant difference between two sowing times. 6. Dry matter yield of grasses was significantly higher (P<0.05) in the forest grassland than in the full-sunlight grassland, and yield was influenced by sowing time. Higher yield (4,011 kg/ha) was produced in the plot of the forest grassland with early spring sowing. 7. From above results, it is suggested that grassland improvement by spring sowing in the forest is possible, and it is desirable to sow in early spring.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.190-201
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• 2022

Background: The introduction of new living modified (LM) crops may pose a latent threat to the biodiversity of each country. Here, we used sunflowers (Helianthus annuus L.) as a study system to investigate the potential for invasiveness of LM crops under different environmental conditions when released into a natural ecosystem in South Korea. We examined the seed germination, survival, and flowering of sunflowers under competition with wild plants at different sowing dates (March-December) and plot sizes (1 m × 1 m and 2 m × 2 m). Results: The germination rate showed a significant difference according to the sowing date. In addition, several sunflowers survived in plots with a high germination rate, which also led to a higher flowering rate. We found that the smaller the plot, the smaller the area available for inter-species competition, and the higher the number of surviving sunflower plants. The relative dominance and importance value of the species varied significantly between the sowing dates; in particular, sunflowers sown in March could compete with wild plants for longer than those sown on other sowing dates. Conclusions: These observations indicate that the potential for invasiveness of sunflowers differs depending on the environmental conditions and seed density at the time of release.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.19-22
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• 2008

This experiment was conducted at Sangji university in Wonju, Korea from 2005 to 2006. The results obtained were summarized as follow; The Chung-ju local variety was tested to find out the possibility of transplanting of seedling as a after-barley crop. When transplanting of seedling for a after-barley crop was test, this short-day plant flowered from september 1 to september 3, showing no connection with sowing time nor seedling periods. The yield of seeds per 10a was affected by both the sowing time and the seedling periods and its peak in the plots sowed on May 15 and transplanted on June 24(40 days seedling).

• Journal of Animal Science and Technology
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• v.47 no.3
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• pp.475-480
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• 2005

Surface sowing is one of the most important methods to establish and improve grassland. An interest in seed-coating technique for surface sowing has been increased tremendously in the world today. An experiment was conducted to develop a technique for pelleting seeds for pasture production in woodlands. Results showed that pelleting seeds was a better technique than coating seeds because the pelleting reduced coating time of seeds, and it increased the amounts of coated seeds per hour. The pelleting technique was able to minimize damage to seeds through the lower temperature processing and by reducing time for drying, thus, germinating energy, and germination rate of pelleted alfalfa seeds improved. Emergence, establishment, and early growth of alfalfa from pelleted seeds were also improved in woodlands. Based on this study, we could conclude that the seed-pelleting is a very useful technique for the establishment and early growth of alfalfa in woodlands.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.91-91
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• 2022

Popcorn grains are consumed around 10,000 tons per year, in South Korea. It is consumed in amusement parks, movie theaters and snacks. The size of the popcorn processed market in Korea is estimated to be 3.6 billon won per year. So, the popcorn grain market has good prospects. On the other hand, domestic grain is at the level of 1 %, which is less domestic production than the size of the market. Maize Research Institute has developed domestic varieties in order to increase the use of domestically produced grains. The Oyrunpopcorn variety which was commonly distributed is a preferred cultivar because it has a good popping rate compared to imported grains. In addition, 'G-Popcom', 'Oyrun #2' and 'Kichan Popcorn' were developed, which diversified the choice of the farmers. Yield per unit area is important to improve farmers' income. At present, domestic grain production is traded at 5,000 won/kg, so if the yield improves, a high farmer^ income is expected. Therefore, this study compared the growth characteristics and yield according to the appropriate sowing time and plant density to improve the yield of domestically grown popcorn. We used 'Oryunpopcorn', for this research. Agronomic characteristics were compared by sowing times April 23, May 22 and June 22. The 100 seeds weight were 15.9g, 17.7g and 15.0g, respectively. Kernel weight planted in May 22 is the highest value. Yield per 10a were 414kg, 434kg and 296kg, respectively. It shows the yield planted in May 22 was higher than other trials. Therefore, the sowing time to increase the kernel weight and yield is appropriate for planting in mid-May. The number of plants in planting density trial was 5,700 plants, 4,700 plants and 4,000 plants in 10a area. Plant height at each trial were 221 cm, 214cm and 218cm, respectively. It was the highest height in 5,700 plants trials. The 100 kernel weight were 14.8g, 15.9g and 16.5g, respectively. Low planting density trial indicated high kernel weight. Yield per 10a was 415kg, 357kg and 314kg, respectively. It was higher at high density trial than other experimental plots. Therefore, appropriate sowing time was in mid-May and planting density was 5,700 plants/10a in order to increase the yield of popcorn in South Korea. This study will be useful for farmer's income to use the domestic cultivars.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.305-305
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• 2017

Seoritae with green cotyledons refers to Korean native black beans harvested when the frost falls because the maturity is late. It is one of the beans preferred by consumers because of its softness and high sugar content. Because of late maturity, if the agricultural work is delayed by weather or agricultural schedule in green cotyledon black soybean (Seoritae), it affects seriously harvest and yield of soybeans. The aim of this study was to investigate the marginal seeding period on June 30, July 10 and July 20 in Cheongju and Jecheon area in Korea to produce stable soybean yield. The yields of green cotyledon black soybean as seeding date in Cheongju area are as follows: Seolitae (Yeoncheon), Seoltae (Goesan) and Seoritae (Gogseong), which increased by 23%, 56%, 23% and 40%, respectively, compare to July 10th to June 30th. As soybean sowing is delayed, the quality of soybean seeds has decreased due to the increase of immature seeds and fungal damaged seeds. The contents of anthocyanin in Cheongju area a functional substance of soybeans, was high on July 20 for Heukcheong, on June 30 for Seolitae (Yeoncheon), on July 10 for Seoritae (Goesan). The yields of Heukcheong and Seolitae (Yeoncheon) in Jecheon area were increased by 5% and 17%, respectively, compare to July 10th to June 30th, while Seolite (Goesan) and Seolite (Gogseong) were high in yields on June 30th. Similarly in Cheongju area, as the sowing period is delayed, the number of immature and mold damaged seeds in Jecheon area increased. The contents of anthocyanin in Jecheon area was high on July 10 for Heukcheong, on June 30 for Seolitae (Yeoncheon) and Seolitae (Goesan). From the above results, Sowing marginal date of green cotyledon black soybeans (Seolitae) in Cheongju area increased 30% in sowing on July 10 and increased 2% in sowing on July 20 compared to June 30. And Sowing marginal date of green cotyledon black soybeans (Seolitae) in Jecheon area increased 2% in July 10 compared to June 30, and the yield decreased rapidly on July 20. We have identified the seeding time limit of green cotyledon black bean in Chungbuk province. It will be possible to provide a variety of crop selection after double cropping of farmers. And by knowing the yield and seed quality of soybean according to sowing date, farmers will observe appropriate sowing period of soybeans for high quality. From the viewpoint of consumers, functional substances of Seoritae will meet the desire for health.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.285-294
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• 2011

Glucosinolate (GSL) contents were investigated (i) at 1~7 days after sowing (DAS) in seed sprouts and (ii) at 3-7 weeks after sowing for the time-course. Moreover, (iii) They were compared with five different cultivars of rocket salad (Eruca sativa). Seventeen GSLs were separated by HPLC analysis, and 10 GSLs among them were identified as glucoraphanin, sinigrin, glucoalyssin, diglucothiobeinin, glucobrassicanapin, glucoerucin, glucobrassicin, dimeric, 4-mercaptobutyl GSL, 4-methoxy glucobrassicin, gluconasturttin by using LC-APCI-MS analysis, but 7 compounds were not identified. (i) The total GSL content in seed sprouts initially increased up to 3 DAS and then decreased according to their seedling growth. In particular, glucoraphanin known as a strong anti-cancer reagent was found the highest level (5.05 ${\mu}mol/g$ dry wt.) at 3 DAS. The most abundant GSL was glucoerucin ranged from 26.0~49.6 ${\mu}mol/g$ dry wt. (ii) In the time-course, the total GSL contents increased dramatically from 3-week (5.91 ${\mu}mol/g$ dry wt.) to 7-week after sowing (32.2 ${\mu}mol/g$ dry wt.). The major GSLs were glucoraphanin, glucoerucin and 4-methoxy glucobrassicin. (iii) By comparing GSL contents with five different cultivars, the total GSL contents increased from 4-week to 6-week after sowing, regardless of cultivar. In 4-week-old, the order with the total GSL content was "Rucola" > "Rocket Herbs" ${\geqq}$ "Odyssey" > "Takii" > "Herb", but in 6-week-old it is changed as "Takii" > "Herb" > "Odyssey" > "Rucola" > "Rocket Herbs" even there was almost no significantly difference between them.