• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.259-267
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• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• Plant Resources
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• v.8 no.2
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• pp.91-95
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• 2005

In spring, to determine the optimal planting date and plant density of rapeseed in southern areas of Korea. $Taiwan^{\#1}$ variety for spring sowing, the highest yielding variety was grown under five different planting date and plant density. Yield components such as plant height, ear length, number of seedling stand per $m^2$, number of per ear and seed set percentage were highest at the plots with Mar. 5 of planting date and 50/20cm drilling of plant density. Yield of seed, oil, gas and 1,000 grains weight and erucic acid content were highest at the Mar. 5 of planting date and 50/20cm drilling of plant density. Judging from the results reported above, at optimum planting date and plant density of rapeseed seemed too be Mar. 5 of planting date and 50/20cm plant density in spring sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.166-170
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• 2012

This research was carried out to choose the suitable seedling type to transplanting in order to stabilize rice yield. The brief of this research to transplant the seedling divided into 10-day seedling, 20-day seedling, 30-day seedling, 33-day pot seedling in the field of Saemangeum Gyehwa, newly reclaimed land were following; Average salt content in 2 years was reduced from 0.16% to 0.04% after transplanting. Heading date of seedling type was Aug. 14 at 33-day pot seedling compared to 2 days at 30-day seedling, 3 days at 20-day seedling, 5 days late at 10-day seedling. Lodging index was highest at 30-day seedling, and also, field lodging was 50%. Ripening ratio and 1,000 grain weight were similar and panicle number was higher 20-day seedling > 10-day seedling > 33-day pot seedling > 30-day seedling. Rice yield was higher 10-day seedling = 20-day seedling > 33-day pot seedling > 30-day seedling. Head rice ratio was higher in 20-day seedling > 30-day seedling = 10-day seedling > 33-day pot seedling. Amylose content and protein content was not significantly different between seedling types. With this results, the suitable seedling types in newly reclaimed land are 10-day and 20-day seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.487-498
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• 1992

To study the effects of different nursing methods and transplanting on the growth of rice plant (Oriza sativa L.) in southern region of Korea, Kumo-byeo, Palgong-byeo and Dongjinbyeo were transplanted from April 20 to July 20 at an interval of 15 days with 8 days old seedling (infant seedling) and 25 days old box-seedling for machine transplanting, and 45 days old conventional seedling. Threshold transplanting date in southern region of Korea were June 26 for 8 days old seedling, July 1 for 25 days old seedling and] July 11 for 45 days old seedling for Kumo-byeo, and June 21, June 30, July 10 for Palgong-byeo, June 10, June 24, July 5 for Dongjin-byeo, respectively. Yield has no uniform tendency according to the transplanting date. However, yield were greater in the order of 8 days old seedling >25 days old seedling> 45 days old seedling in Kuma-byeo and 25 days old seedling (equation omitted)8 days old seedling (equation omitted)45 days old seedling in Palgong-byeo, 45 days old seedling(equation omitted)25 days old seedling(equation omitted) 8 days old seedling in Dongjin-byeo. The optimum accumulated air temperature during yield productive stage around heading (40 days from 10 days before heading to 30 days after heading) for high yield were 1,003$^{\circ}C$ for 8 days old seedling, 1,014$^{\circ}C$ for 25 days old seedling and 1,027$^{\circ}C$ for 45 days old seedling in Kumo-byeo. And they were 1,018$^{\circ}C$, 1,015$^{\circ}C$, 1,086$^{\circ}C$ in Palgong-byeo and 998$^{\circ}C$, 984$^{\circ}C$, 949$^{\circ}C$ in Dongjin-byeo, respectively. Earlier transplanting with 8 days old seedling showed higher ratio of broken rice and green kerneled rice in Kuma-byeo, and late transplanting after July 5 showed significant high rate of green kerneled rice. Palgong-byeo and Dongjin-byeo also showed high rate of green kerneled rice at transplanting after July 5.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.86-87
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• 2000

• Plant Resources
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• v.8 no.3
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• pp.258-262
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• 2005

In autumn, to determine the optimal planting date and plant density of rapeseed in southern areas of Korea, Yudal variety for autumn sowing, the highest yielding variety was grown under three different planting dates and five different plant densities. Yield components such as plant height, ear length, number of seedling stand per $m^2$, number of branches and pod length were highest at the plots with Sep. 30 of planting date and 30/20 cm drilling of plant density. Yield of seed, oil and 1,000 grains weight were highest at the Sep.30 of planting date and 30/20 cm drilling of plant density. Judging from the results reported above, at optimum planting date and plant density of rapeseed seemed to be Sep.30 of planting date and 30/20cm plant density in autumn sowing.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.114-120
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• 1994

Experiment was conducted to investigate the effects of planting date and planting methods with seedling size on bolting and yield of Ostericum koreanum (MAX.) KITAGAWA Seeding methods were also reviewed to imvestigate their effects on seedling characteristics. This experiment was carried out in Chuncheon during 1988 growing season. The small seeding rate and broadcasting had higher rates of emergence than the others. There was no big difference in seedling size by seedling rate, and more seedling growth was in drilling methods among seed planting methods. The quantity of seedling were produced with the order of medium, small and lastly large seedling. Dense planting $(8l\;/33m^2)$ was advantageous in producing small seedling. Large seedling had earlier flowering than the others and growth was good in planting small seedling with drilling method. The rates of bolting by seedling sizes were 89.6% in large, 64.6% in medium and 36.9% in small seedling. Bolting was influenced the root Quality by producing lignified root which had a least commercial value. More root growth was shown in unbolting plant compared to bolting plant seedling and broadcasting had much more root growth than seedling from drilling. Fresh root yield of unbolting plant was higher than that of bolting plant and highest yield was obtained in the broadcasting plot with small seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.260-264
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• 2009

Sufficient seedling establishment of Chinese milk vetch (CMV) is the most important factor in the CMV cultivation. In order to obtain sufficient seedling stand, CMV seed should be planted at right seed planting date. An optimum CMV seed planting time for stable seedling establishment was determined based on the final water drainage time for rice harvest in fall. Five planting times from 10 days before water drainage (DBWD) to 15 days after water drainage (DAWD) at five day interval were evaluated during the period of 2006-2007 and 2007-2008 and the optimum CMV seed planting time was determined based on seedling stand, winter survival rate, and dry matter production. CMV seedling stand before winter was high with $575{\sim}1,050\;plants/m^2$ regardless of seed planting times but after overwintering, it was greater in seed planting date between 5 DBWD to 5 DAWD than that of 10 to 15 DAWD treatments. Winter survival rate, dry matter production and seed production yield also showed similar trend to the seedling establishment. On the other hand, when CMV seeds were sowed early at 10 DBWD, seedling stand and winter survival rate were lower than that of 5 DBWD to 5 DAWD. This result indicates that an optimum CMV seed planting time based on the final water drainage could be between 5 DBWD (September 20) to 5 DAWD (September 30).

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.94-101
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• 2001

This study was intended to evaluate the relationship environmental condition and growth characteristics of seed treatment seed in direct sowing with different sowing date, and to suggest new cultivation model. The emergence percentage and hours were down as the delayed sowing date. Optimum sowing time was Sep. 10, and sowing must end before Sep. 20 for safety yield. When did sowing ended before Sep.20 in direct sowing cultivation, the seedling growth(SG) and No of roots of direct sowing seedling were larger than transplanting cultivation . At March 8 evaluated seedling, the SG of direct sowing seedling was higher than transplanting, and at Sep. 2(1 those were similar. The missing plant rate in transplanting cultivation was under 3 %, and that in direct sowing cultivation was about 13∼18%, and the extent were sever as delayed sowing date. The bulb fresh weight was decreased as delayed sowing, and those in direct sowing and transplanting cultivation were 230, 217g, respectively. The blot rate was high in direct sowing cultivation, and that was decreased as delayed sowing. The yield in direct sowing and transplanting cultivation were 5,134, 5,300kg, respectively, and those were decreased as delayed sowing. The average yield in early and medium-late maturity cultivars were 3,750, 4,908kg, respectively, and Sonic was highest yield in early maturity cultivars and Nongwoodego was highest in medium-late maturity cultivars. The emergence weed were 9 species as Loportea bulbifera Weddell and others, and Loported bulbifera Weddell, Digitaria violascens Link and Persicaria longiseta Kitagawa were dominant species in direct sowing cultivation with black hole vinyl mulching

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.223-229
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• 1996

To investigate the effect of seeding date, seeding rate, and sprouted seeds on seedling establishment, yield and its components of rice in barley /rice reley cropping as a minimum tillage, Gancheokbyeo rice seeds sowed by hand broadcast in various overlapped days befer barley harvest. The highest rice seedling stand was at sowed on the day just before barley harvest and l00kg per hectare of seeding rate with sprouted seeds. Also number of tiller and panicle showed the similar tendency. Delayed rice heading dates were found 2 days at l0-day overlap, 2 days at 5-day overlap, and 4 days at 0-day overlap before barley harvest compared with machine transplanting rice at just after barley harvest using l0-days old seedling. The culm length of broadcast rice shortened 2∼4cm compared with the transplanting rice. The rice plants lodged slightly at seeding rate l00kg per hectare and at sowed on the day of barley harvest. The rice panicle number increased with later date sowing and higher seeding rate. Number of spikelets per panicle and ripened grains decreased at higher seeding rates. Sprouted seeds and higher seeding rates showed higher rice yield at later sowing dates.