• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.61 no.4
• /
• pp.235-241
• /
• 2016

Three different transplanting dates for two rice cultivars grown in Daegu, Republic of Korea, were examined to identify the changes in growth, rice quality, and characteristics of amylopectin. An early transplanting date caused a reduction in the number of panicles in both rice cultivars compared to that in the optimal and late transplanting dates. The 1000-grain weight in the two rice cultivars was significantly increased in the late transplanting date. The rice cultivar tolerant to high temperatures, Donganbyeo, exhibited the lowest milky grain rate in the late transplanting date. The highest rate of head grain was observed in the late transplanting date in both rice cultivars. Regarding the pattern of pasting properties, peak viscosity increased with delayed transplanting dates. With respect to changes in the amylopectin branch-chain length distribution, the amylopectin structure of the translucent Dongan rice cultivar transplanted on April 25 was characterized by a significant increase in A chains with DP > 12, and a decrease in long chains $DP{\geq}37$ compared to that transplanted on June 25. In contrast, the amylopectin structure of the chalky Dongan rice cultivar transplanted on April 25 exhibited further decrease in 13 < DP < 19 than that transplanted on June 25. In the Ungwang rice cultivar, the amylopectin structure of the translucent Ungwang rice cultivar transplanted on April 25 and June 25 was characterized by a significant decrease in the lengths of total amylopectin chains. Furthermore, the amylopectin structure of the chalky Ungwangbyeo rice cultivar transplanted on April 25 was characterized by a significant increase in 7 < DP < 30, while a significant decrease was observed in that transplanted on June 25. These results indicate that the amylopectin structure is altered by different transplanting dates depending on the characteristics of the rice cultivar.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.3
• /
• pp.352-356
• /
• 1997

In order to trace the survival route of weedy rice in Korean farmer's field, occurrence rate and position of weedy rice, number of weedy rice plants per $m^2$, in transplanted and direct seeded field were investigated. The highest occurrence rate of weedy rice in transplanted field was 5.5％. Number of weedy rice plants in direct seeded field was higher than that in transplanted field. In transplanted field, most of the weedy rice were grown within hills of cultivated rice and only a few was grown between hills of the cultivated rice, however in direct seeded field the number of weedy rice occurred between hills or rows of cultivated rice was higher than that occurred within hills or rows. Weedy rice occurrence rate in the field of .non-recommended rice variety was higher than that in the field of recommended variety. The main survival route of weedy rice in transplanted field was supposed to be mixture of weedy rice seeds with cultivated rice, and that in direct seeded field to be natural survival.

• Korean journal of applied entomology
• /
• v.36 no.2
• /
• pp.141-144
• /
• 1997

Studies were conducted to investigate the incidense of insect pests in transplanted and direct seeded paddy fields in southern region of Korea. Population dencities of the rice green leafhopper (RGLH: Nephotettix cincticeps Uhler) and rice leaffolder (RLF: Cnaphalocroch medinalh Guenee) were higher in machine transplanted than in direct seeded, but the brown planthopper (BPH: Nilaparvata lugens Stal) and smaller brown planthopper (SBPH: Laodelphax striatellus Fallen) were abundant in direct seeded. However, no significant difference was found between machine transplanted and direct seeded fields in the incidense of rice stem borer (RSB: Chilo suppressalis Walker), whiteback planthopper (WBPH: Sogatella furcifera Horvath), and rice stem magot (RSM: C'hlorops oryzae Matsumura). Occurrence of rice key pests were affected more by transplanting time than other cultural practices. Later transplanting induced higher populations of BPH, WBPH, SBPH, RGLH. However, RSB and RLF caused higher damage in earlier transplanted paddy field.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.317-317
• /
• 2017

We performed this experiment to select high quality rice adapted to wheat-rice double cropping system. We sowed barley and wheat seed in November 2, 2015. After harvesting barley and wheat, we transplanted high quality rice cultivars: 'Unkwang', 'Hopun', 'Haepum', 'Hyunoum' in June 17 and 24. We used 'sindongjin' rice as a control. As a result, 'Hyunpum' had a highest head rice yield regardless of transplanting date. Head rice yield of 'Hyunpum' was 488.1kg/10a when transplanted in June 17, and 453.6kg/10a when transplanted in June 24. The reason for this highest head rice yield was not percentage of head rice but milled rice yield. Milled rice yield of 'Hyunpum' was 526.5kg/10a when transplanted in June 17, and 490.0kg/10a when transplanted in June 24. Percentage of head rice had little differences between rice cultivars. Among yield components, only number of panicle per $m^2$ had an effect on the differences of yield between rice cultivars. The other yield components didn't have an effect on the differences of yield between rice cultivars. Compared to June 17, only 'Unkwang' had higher head rice percentage and head rice yield in June 24. Head rice percentage of 'Unkwang' changed from 67.3% to 85.0% and head rice yield changed from 324kg/10a to 393.8kg/10a when transplanting date delayed from June 17 to June 24. When transplanting date was delayed, heading date of 'Unkwang' was more delayed than other rice cultivars. By delay of heading date, mean temperature for 40days changed from $25.0^{\circ}C$ to $22.9^{\circ}C$ which improved temperature condition during grain filling stage. This improved head rice percentage and head rice yield of 'Unkwang' transplanted in June 24. If transplanting date is more delayed than June 24, 'Unkwang' could have higher head rice percentage and head rice yield. Therefore, if you transplant rice before June 24 in rice-wheat double cropping system, 'Hyunpum' is recommended as adequate rice cultivar. But if you transplant rice after June 24, further research is needed to find out adequate rice cultivar.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.spc1
• /
• pp.33-36
• /
• 2005

In order to find out better cultivation practices in mid-mountainous area to produce high quality rice, an experiment involving four transplanting times and four varieties was carried out, during past three years $(2002\~2004)$. There was no significantly different on palatability of rice between transplanting time, but an interaction effect was between transplanting time and variety, The palatability of milled rice of Sangmibyeo, Hwayongbyeo and Junambyeo transplanted at May 10th were higher than Samcheonbyeo. The palatability of milled rice grown by May 20th day's transplanted, Sangmibyeo and Junambyeo were higher than Samcheonbyeo. The palatability of milled rice grown by May 30th day's trans-planted, Sangmibyeo and Hwayongbyeo were higher than Samcheonbyeo and Junambyeo. And the palatability of milled rice grown by June 9th day's transplanted, Sangmibyeo and Samcheonbyeo were higher than Hwayongbyeo and Junambyeo. It can infer that Sangmibyeo is one of the best option over the transplanting times in term of palatability, Amylose content of milled rice was showed without a significant difference between transplanting time, but there was an interaction effect between transplanting time and variety. The amylose content of grown by May 20th day's transplanted, Sangmibyeo and Samcheonbyeo were lower than Junambyeo. The amylose content of milled rice grown by June 9th day's transplanted, Sangmibyeo and Samcheonbyeo were lower than Hwayongbyeo and Junambyeo. And the amylose content of milled rice grown by May 10th day's and May 30th day's transplanted, was showed without a significant difference between variety. The protein content of milled rice grown by later season transplanted was lower than grown by earlier, The head rice yield wasn't different significantly between the treatment of transplanting times and varieties. But the yield of milled rice grown by transplanted at May 20th day was high most in between the treatment of transplanting time. In a conclusion gathering all above the results, 20th May day's transplanting time and Sangmibyeo was one of the best option for producing high quality rice among the treatments in considering with head rice yield, palatability, amylose${\cdot}$protein content and productivity, at Mid-mountainous area.

• Korean Journal of Agricultural Science
• /
• v.46 no.3
• /
• pp.629-636
• /
• 2019

This study was conducted to investigate the growth characteristics and yield of whole green rice grains during the ripening period. These were investigated using Hopumbyeo and Unkwangbyeo at two transplanting times and with two kinds of nitrogen fertilization. The transplanting times were May 30 and June 20, respectively, using 30-day seedling culture and transplanting conducted with 3 - 4 plants per hill in planting space of $15cm{\times}30cm$. During nitrogen fertilization, 9 kg and 18 kg was used, respectively. The harvest of the green whole rice grains was carried out on the 15th, 20th, 25th, 30th, and 40th day after the heading date. The clum length was greater with later planting and with application of more nitrogen. The rice yield was higher with nitrogen fertilization of 18 kg/10 a when transplanted on May 30 for Hupumbyeo, and for Unkwangbyeo, was higher at 9 kg/10 a nitrogen fertilization when transplanted on May 30. The protein content of Hopumbyeo was higher when the nitrogen fertilizer was 18 kg/10 a, and that of Unkwangbyeo was lower than that when transplanting on June 20. The greenness was not related to the nitrogen fertilization level when transplanted on May 20 but for later transplanting, the greenness was higher when the nitrogen application was increased, and the greenness was the greatest about 30 days after the heading date.

• Journal of agriculture & life science
• /
• v.50 no.4
• /
• pp.59-71
• /
• 2016

The occurrence and growth of grass and sedge weed species were investigated in the transplanted rice fields that have different transplanting dates from Apr. 30 to Jun 19 with 10-day interval. The growth and yield of rice plant grown without weed control examined in each plot that has different transplanting dates. Both grass and sedge weeds showed greater plant numbers in the early transplanted plots(Apr. 30 and May 10) than late transplanted plots. Based on the occurring number and dry weight of weeds, the experimental plots were classified into two groups, early group and late group. Weed occurrence and growth were not dramatically different within a group even the occurrence was enhanced as delayed transplanting. Echinochloa spp. that was the most problematic weed showed higher dry weight in early-transplanted field until July, however, the greater dry weight was observed in the late-transplanted plots after August. Sedge weeds including Eleocharis kuroguwai and Scirpus juincoides showed persistently higher value of dry weight in early-transplanted plots than late plots over the experimental period. As the puddling was conducted earlier, emergences of grass and sedge weeds were occurred early and weed growth rate became greater. Therefore, growth and yield of rice that transplanted early decreased more strongly due to the strong suppression by grass and sedge weeds showing the enhanced weed growth rates in early-transplanted plots. Based on the weed growth rate, the adverse effects of grass weeds was maintained for longer period than sedge weeds that showed higher growth rates before heading date of rice plant.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.4
• /
• pp.442-447
• /
• 2015

This research analyzed the characteristics of varieties of rice such as a harvest time and yield, and to select a proper variety to product green rice according to a conventional planting culture and a late planting culture. The most proper harvest time of rice, in general, was 15 to 25 days after heading to product the green rice. Sinsunchal among glutinous rice varieties and Chilbo among nonglutinous rice varieties showed the most amount harvest at 25 days after heading, which was a limit harvest time for the whole green rice production in overall rice varieties. The amount of green rice according to transplanting times, the May $30^{th}$ transplanting was more than the June $20^{th}$. The yield of green rice harvested at 15~25 days after heading was varied according to varieties. Proper glutinous varieties for green rice production were Dongjinchal, Sangdongchal, Boseokchal, and Sinsunchal, in order of listed, which were transplanted at the May $30^{th}$. Meanwhile, Boseokchal, Backokchal, and Sinsunchal, in order of listed, were proper varieties for green rice production, which were transplanted at the June $20^{th}$. In nonglutinous rice, Samkwang, Nunbora, and Chilbo, which were transplanted at the May $30^{th}$, were proper varieties for green rice production. Hwanggeomnodeul, Hopum, and Chilbo, which were transplanted at the June $20^{th}$, were proper varieties for green rice production.

• Journal of the Korean Geographical Society
• /
• v.38 no.1
• /
• pp.48-69
• /
• 2003

Colonialism heretofore described merely as a political economic phenomenon denotes another aspect, namely, an ecological imperialism that accompanies the biological implantation of human beings, crops, weeds, domestic animals, and pathogens onto colonized lands. Foremost, the Korean Peninsula during the colonial period served as a testing ground for the transplanted Japanese varieties of rice. Near the mid-1940s, the new varieties came to dominate over 90% of cultivated rice paddy. The speedy diffusion of transplanted rice was attributable to the aggressive promotion of agricultural institutions led by the Institute of Agricultural Tests and Experiments. Various policies and tactics were also instrumental to the nationwide distribution of new varieties, and they included naming recommended varieties, sponsoring rice contests, establishing crop inspection offices, educating young farmers at training camps, and publishing newsletters for agricultural societies. The forward and backward linkages that came along with the new varieties of transplanted rice helped to consolidate colonial status quo and to create hybrid agricultural landscapes in the Korean countryside.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.54 no.4
• /
• pp.339-345
• /
• 2009

This experiment was carried out to identify the proper transplanting time at reclaimed saline land in the southwestern area of Korea from 2006 to 2007. The rice cultivars tested were Unkwangbyeo(Early maturing one), Gopumbyeo(Medium maturing one) and Samgwangbyeo, Sindongjinbyeo, Cheonghobyeo, Hopyeongbyeo(Mid-late maturing one). The results are summarized as follows. No. of spikelet per the unit area was lower at transplanting on May 20 and wasn't different in those of the other transplanting time. The ripened grain rate was high transplanted May 20 in Unkwangbyeo, but high transplanted from June 1 to June 20 in Mid-late maturing Cultivar. The yield of head rice was high transplanted June 10 and June 20 in Unkwangbyeo, Sindongjinbyeo, Hopyeongbyeo, but June 1 and June 20 in Samgwangbyeo, Cheonghobyeo. The protein content was high transplanted early in Unkwangbyeo, Samgwangbyeo, and late in Gopumbyeo, Sindongjinbyeo, Cheonghobyeo, but wasn't differ among transplanting time in Hopyeongbyeo. Considering the rice growth, the rice good quality, the yield of milled and head rice, the proper transplanting time was June 10 in Unkwangbyeo, Sindongjinbyeo, whereas was June 10 in Samgwangbyeo, Cheonghobyeo, Hopyeongbyeo.