• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.427-434
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• 2017

This experiment was conducted to investigate the aspect of tiller occurrence, growth and yield of sorghum according to planting distance and sowing date. The object of this experiment is to get basic data to inhibit non-productive tillers uneconomical and cumbersome for mechanical harvesting. Also another object was to evaluate optimum planting distance and sowing date in central district area. Total number of tillers was more in 80 cm ridge than 60 cm ridge and it was increased as the planting distance was wider from 15 cm to 30 cm on the each ridge. Ratio of effective tillers was higher in 60 cm ridge than 80 cm ridge and it was decreased as planting distance was wider from 15 cm to 30 cm. The lower the planting distance, the more increased total number of tillers, whereas effective tillers was decreased as planting distance was high. Average of total number of tillers of three varieties was higher in sowing date of May 2 (1st sowing date), whereas ratio of effective tillers was the highest in sowing date of May 23 (2nd sowing date). Hwanggeumchal showed the highest total number of tillers (1.2 tillers), while Moktaksusu had the lowest total number of tillers (0.8 tillers) among three varieties. There were no significant difference between planting distance and days to heading and ripening date from seeding. Culm length increased as planting distance was high, but ear length, grains per ear and 1000 grain weight were decreased on the other hand. The highest yield of sorghum per 10a was obtained from $60{\times}20cm$ planting distance among 6 planting distances.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.111-118
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• 2015

The objective of this study was to determine the response of rapeseed (Brassica napus) to different planting date in the spring and varieties on growth and flowering characteristics. Eight rapeseed varieties were sowed at 10 day interval from 1st to 31th of March at Muan and Jeju in Korea. Significant planting dates and rapeseed varieties effects for growth, start of flowering and duration. As the planting date was being delayed, plant length and flower number were decreased, but branch number was increased. And, start of flowering date was retarded and flowering duration decreased with later planting date. Days from planting to flowering was shortened as seeding date was delayed and shortening degree was similar between experimental locations, Muan and Jeju. The days to flowering for rapeseed about 73~94 days for 1st March and then decreased to 57~71 days for the 31th March of planting date. 'Tammiyuchae' and 'Mokpo 111' seeded on each planting date come into blossom more earlier about 10 days as compared to 'Tamlayuchae' and 'Naehanyuchae'. The duration of flowering for the B. napus varieties was shortened as planting date was delayed. The results revealed that flowering characteristics of rapeseed can be greatly enhanced by planting as early as possible, and early flowering varieties i.e. 'Tammiyuchae' and 'Spring' were the most suitable varieties among the tested varieties for planting in the spring.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.179-183
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• 1990

In order to find out the effects of nitrogen fertilizer, planting density and seeding date of Okra (Abelmoschus esculentus (L) MOENCH), three nitrogen fertilizer level (4, 8 and 10kg N/10a), three planting densities (45${\times}$30cm, 60${\times}$30cm and 90${\times}$30cm) and five seeding date (April 15, May 1, May 15, June 1 and June 15) were treated. Treatment of 8kg N/10a among nitrogen fertilizer level and 45${\times}$30cm among planting densities showed higher green and yield than the other treatments. The plot of 45${\times}$30cm with 8kg N/10a showed the highest yield. Among planting date, May 1 planting date obtained the highest yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.104-112
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• 2016

A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.215-222
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• 1996

This study was conducted to compare the growth and yield, and to determine the optimum planting date and density in two improved black soybean varieties. The two varieties were planted by driller attached a tractor on May 21 and June 19, 1993, and treated five planting densities, respectively. Yield of Gumjeongkong 1 was similer for both planting dates, but that of Suwon 157 was remarkably reduced on June 19 planting compared to May 21. There was significant differences between planting dates in stem length, number of branches, seeds per plant, seed weight and yield. Planting density, also, significantly affected on stem length, number of branches and seeds per plant. Statistically significant interactions between planting date$\times$variety and planting date$\times$planting density were found at almost all characteristics, except between variety$\times$planting density. Optimum planting date and density of Gumjeongkong 1 for high yield were June 19 and 33, 000 plants per l0a, and those of Suwon 157 were May 21 and 22, 000 plants per l0a, respectively. The coefficient of variation at different planting densities was high at stem length, number of branches, seeds per plant and yield, but low at number of main stem node, seeds per pod and 100 seed weight.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.233-240
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• 1999

Understanding of the relationships between seeding rate and planting date is important for production of spring oats during the fall season. Therefore, this experiment was conducted to investigate seeding rate and planting date effects on forage performance and quality of spring oats(Avena sativa L.) at Suweon in 1997. The experiment was arranged in a split plot design with three replications. The main plots consisted of different seeding rates such as 150, 200, and 250kg/ha. The subplots consisted of different planting dates of spring oats such as 15, 22, and 29 August and 5 September. Dry matter content of oats was significantly decreased(P<0.01) as the planting date was delayed except the planting date of 5 September(24.8%). Dry matter content of forage oats planted on 15, 22, and 29 August was 23.0, 21.5, and 20.5%, respectively. A seeding $rate\;{\times}\;planting$ date interaction for dry matter content was highly significant(P<0.01). Crude protein content of oats was significantly increased(P<0.01) from 15.6 to 27.9% as the planting was delayed, while a significant seeding $rate\;{\times}\;planting$ date interaction for crude protein content of oats was observed. Acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents of oats increased with early planting(P<0.01), but there was no significant difference among the seeding rates. ln vitro dry matter digestibility(IVDMD) of oats was significantly increased(P<0.01) as the seeding rate was increased together with late planting. Average dry matter yield of oats decreased(P<0.01) from 2,647 to 615kg/ha as the planting was delayed, but there was no significant difference among the seeding rates. A seeding $rate\;{\times}\;planting$ date interaction was observed for average dry matter yield of oats that the seeding rate increase in this experiment showed better at early planting dates. Crude protein yield of oats increased from 171 to 410kg/ha as the planting was delayed, and a significant increases(P<0.01) for crude protein yield was found among the seeding rates. ln vitro digestible dry matter(IVDDM) yield of oats decreased(P<0.01) as the planting was delayed, but there was no significant difference among the seeding rates. A significant seeding $rate\;{\times}\;planting$ date interaction for lVDDM of oats was found. The results of this study indicate that both the seeding rate of 200kg/ha and early planting before 29 August would be recommendable for forage yield and quality of oats in Korea.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.356-361
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• 2008

Chrysanthemum indicum L. (Gamgug) has been examined to study their flowering habits, yields and bioactive compounds under different planting densities and mowing dates. The planting density experiment revealed a significantly increasing stem diameter, number of flowers and branches with decreasing plant density in the $100\;cm{\times}30\;cm$ and $130\;cm{\times}30\;cm$ treatments as compared to $70\;cm{\times}30\;cm$ treatments, but not plant height, leaf and flower width. On the other hand, the mowing date experiment showed that growth characteristics of plants were similar to the control plants (not mowing) and June 20 treatment, but July 20 treatments had significantly smaller than the control. The weights (g $plant^{-1}$) of dry flowers were affected by the planting density and mowing date. The flower yield of $586\;kg\;ha^{-1}$ obtained at $100\;cm{\times}30\;cm$ density was 11% and 22% higher than that of $120\;cm{\times}30\;cm$ and $70\;cm{\times}30\;cm$ treatments, respectively. The yield of dry flowers in the control and June 20 mowing date ranged $495-508\;kg\;ha^{-1}$, which is 40-42% higher than the yield in the July 20 treatments. The amount of essential oil (g $plant^{-1}$) in medically valuable flowerheads of C. indicum L. was statistically different between mowing dates but not among planting densities. The study showed that planting density and the mowing date could increase yields of flowerheads. An optimum planting density of $100\;cm{\times}30\;cm$ and mowing date of on or before June 20 is recommended for C. indicum L.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.44-48
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• 1998

Two determinate soybean cultivars, 'Baegunkong' and 'Namhaekong', were planted on 8 Jone, 23 June, and 8 July 1996 at Cheju at planting densities of 33, 43, 53, 63 plants per $m^2$ to determine the optimum planting density of double crop soybean for recently recommended cultivars in Cheju area at various planting dates. The plant height, and the diameter and node number of main stems decreased as planting was delayed. The plant height increased but the stem diameter and node number decreased with increasing planting density. Pod number per plant was greater for Namhaekong than for Baegunkong and was not affected by planting date. Pod number per plant decreased but pod numbers per $\textrm{m}^2$ increased with increasing planting density. The number of seeds per pod was greater at the two later plantings and fewer at the highest planting density. 100-seed weight decreased with delaying planting. The seed weight was lighter at the highest planting density for Baegunkong but there was no difference for Namhaekong among the planting densities. The seed yield of Baegunkong was greater for 23 June and 8 July plantings (2,280 and 2,420 kg/ha) than for 8 June planting (1,450 kg/ha) while that of Namhaekong was greatest at 23 June planting (2,690 kg/ha) compared with 8 June and 8 July plantings (1,890 and 2,080 kg/ha). Across the planting dates and cultivars, seed yield increased from 1,860 to 2,290kg/ha as the planting density increased from 33 to 53 plants/$\textrm{m}^2$ and then leveled off with a further increase in planting density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.86-94
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• 1996

This experiment was carried out to investigate the differences of the growth and yield characteristics at different planting dates in two soybean ecotypes from 1993 to 1994. Two summer types of soybean varieties, Suwon 163 and CNS 342, and two autumn types, Hwangkumkong and Keomcheongkong ＃1 were planted 7 times from 22 April to 21 June with 10 days interval in 1993 and 4 times from 22 April to 21 June with 20 days interval in 1994 at experimental field, Dankook University, Cheonan. Emergence rate was shown to difference between the summer types and the autumn types, as planting date delayed and between 1993 and 1994. The average emergence period was more shortened in 1994 than 1993. This was reduced as planting date delayed. Days to flowering, pod formation and maturity were shortened as planting date delayed, and observed that shortening of days to flowering and maturity were smaller in the summer types than the autumn types. Stem height, stem diameter, number of mainstem nodes, number of branches and number of branch nodes were different between the summer types and the autumn types and between 1993 and 1994. These were reduced as planting date delayed. The number of pods per plant was also different between 1993 and 1994, and reduced as planting date delayed. The number of seeds per pod was not different between 1993 and 1994, and shown to similar tendency as planting date delayed. It was observed that one hundred seed weight of the summer types were reduced, but the autumn types were not as planted date delayed in 1993. In 1994, one hundred seed weight was not measured because almost all pods were unfilled or shriveled probably due to high temperature during pod formation period. The rate of unfilled pods per plant was higher the autumn types than in the summer type of soybeans in 1994.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.434-438
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• 2001

Two late-maturing perilla cultivars for vegetables, ‘Ipdlkkae 1’ and ‘Manbaekdlkkae’, were planted on 15 May, 30 May, 15 June, 30 June, and 15 July in 2000 to determine the optimum planting date for seed production in Jeju Island. Significant interaction between cultivar and planting date was observed for number of days from planting to maturity. There were significant differences between two cultivars for days to flowering. Ipdlkkae 1 flowered two days earlier but matured one day later than Manbaekdlkkae. As planting was delayed from 15 May to 15 July, when averaged across two cultivars, days to flowering and maturity decreased from 137 to 77 days and 179 to 121 days, respectively. As planting was delayed, stem length, number of branches per plant and number of node on the main stem decreased from 150 to 81 cm, 17.0 to 7.3, and 16.9 to 10.3, respectively. Number of clusters per plant decreased 65.6 to 50.7 with delayed planting but number of capsules per cluster was not significantly affected by planting date. With delayed planting, 1,000-grain weight increased 3.2 to 3.9 g, but grain yield decreased from 1,820 to 1,338 kg/㏊. However, there was no significant difference for grain yield between 15 and 30 May plantings. The results of this study suggest that the optimum planting date for seed production of late maturing vegetable perilla may be from early May to late May in Jeju Island.