• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.182-191
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• 2020

A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas have lower optimum grain filling temperatures for yield improvement than the varieties from South Korea. Three varieties originated from North Korea and three varieties from northern China were compared to the same number of varieties from South Korea. In a field study, the optimum grain filling temperatures over 40 days after heading were 22.6 - 23.0℃, 21.5 - 22.3℃, and 21.5 - 23.6℃ for the varieties from North Korea, northern China, and South Korea, respectively, resulting in no significant difference among varietal groups. Meanwhile, the heading dates of the early maturing varieties from North Korea and China were 7 - 12 days earlier than that of the early maturing Odae variety from South Korea during the first transplant of 2017. The phytotron study, in which different temperature regimes were imposed from flowering/fertilization to harvest with constant daily mean temperatures, revealed that milled rice weight did not decrease under low temperatures, even at 16℃, compared to that at 22℃. At the fourth transplant in the field study, mean temperature lower than 10℃ appeared before rice grains were fully developed, resulting in yield reductions. It was concluded that rice varieties adaptable to high-altitude areas do not have lower optimum grain filling temperatures but, instead, possess shorter growth durations. It was further suggested that the optimum grain filling temperature of rice observed under natural conditions could be attributed to the lowering temperature at the late filling stage under temperate climatic conditions.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.19-29
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• 1999

This experiment was conducted to compare with the growth and fruit quality of Citrullus lanatus cv. Mudeungsan and Citrullus vulgaris cv. Dalgona grown in fertigation and soilless culture. Seeds were sown on April 16 and transplanted on April 24, 1998. Cultural systems used in fertigation and soilless culture beds using mixed substrate, coir dust (50%) and perlite (50%). In the plot of fertigation system, the number of leaves of cv. Dalgona were increased more than that of cv Mudeungsan, but leaf area shown inversed trend. Plant growth shown greater in soilless culture than those of fertigation culture. In regardless of cultural systems, soluble solid content in fruit was higher in the cv. Dalgona than that of cv. Mudeungsan, but fruit fresh weight was greater in cv. Mudeungsan compare to the cv Dalgona. Nitrate content in petiole sap of watermelon in regardless of cultivars and cultural systems was 11.4∼13.4mg/gFW on 15 days after transplanting, and then increased to 17.1∼20.6mg/gFW on the fruit growth stage. Phosphorous content was 3.7∼5.7mg/gFW in the early growth stage while decreased to 0.6∼1.1mg/gFW from maturing stage to harvesting stage. Potassium content was increased to 5.8∼6.6mg/gFW in the early growth stage while decreased to 4.0∼4.8mg/gFW from pollination stage to harvesting stage. Calcium content in spa petiole of watermelon was higher in soilless culture as 3.4∼4.1mg/gFW than 2.5∼3.5mg/gFW of fertigation culture, but calcium content in fertigation culture during maturing stage was higher than that of soilless culture. The tendency of magnesium uptake was higher in fertigation culture than that of soilless culture, and was similarly absorbed in the range of 0.9∼1.3mg/gFW in regardless of cultural method after pollination. It was demonstrated that cv. Mudeungsan can be adapted to soilless culture and improved the fruit quality. Consequently, hydroponic possibility for year round culture in the greenhouse was recognized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.195-201
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• 2012

It is important to determine the optimum harvesting time that impact decisively on the quality of vegetable waxy corns. In general, it takes 20~25 days from silking to harvest according to ecotype when waxy corn hybrids were sown in April. We identified the optimum harvesting time by the ecotypes and seeding dates for the establishment of corn double cropping system of waxy corn. It takes 23~25 days from silking to harvest regardless of ecotype, when waxy corns were sown at early in April or late in June. It takes 28~31 days when Chalok1, early maturing type, was sown between in July 10, and in July 30. It takes 29~31 days when Ilmichal, medium late maturing type, was sown between in July 10 and in July 20, but 39 days were required when sown at in July 30. The cumulative temperature for harvesting was about $1700^{\circ}C{\sim}2100^{\circ}C$. The minimum cumulative temperature from seeding to harvest was approximately $600^{\circ}C$. These results will be helpful to the farmers for determining the optimum harvest time of vegetable waxy corns.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.304-310
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• 2017

This study was conducted over a 3-year period from 2013 to 2015 in the mid-northern inland, Cheolweon, Korea, to investigate changes in flowering date, daily mean temperature during grain filling, and yield characteristics affected by transplanting date in an early-maturing rice variety, 'Joun'. Thirty-day-old seedlings were transplanted at four different dates at 15-day interval from May 5 to June 19. Flowering dates were July 16, July 21, July 31, and August 14 when transplanting was performed on May 5, May 20, June 4, and June 19, respectively. Late transplanting resulted in higher daily mean temperature before flowering but late-transplanted rice required fewer days and lower cumulative temperature to reach flowering from transplanting. As transplanting was delayed, daily mean temperature for 40 days after flowering decreased, whereas daily sunshine hours for the same period increased, with a temperature of $24.8^{\circ}C$ and sunshine for 5.8 hours being recorded at the transplanting on May 5, and with a temperature of $21.0^{\circ}C$ and sunshine for 7.7 hours at the transplanting on June 19. With late transplanting, panicles per square meter significantly decreased, whereas spikelets per panicle showed an increasing trend. Regression analysis showed that maximum head rice yield was attained from the transplanting on May 18, for which the flowering date was July 21, and daily mean temperature for 40 days from that flowering date was $24.6^{\circ}C$. A decrease in head rice yield by 5% and 10% of the maximum was observed for rice transplanted on June 6 and June 15, which resulted in flowering dates of August 2 and August 11, respectively, and the daily mean temperatures for 40 days from flowering were 23.2 and $21.7^{\circ}C$, respectively. Therefore, in mid-northern inland, it is recommended to transplant 'Joun' on May 18 to induce flowering on July 21, when grain filling is subjected to a daily mean temperature of $24.6^{\circ}C$ during active filling stage.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.549-553
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• 2011

'Jungmo 1012', a new japonica rice intermediate parent developed from a cross between 'Sambaegbyeo' having a good eating-quality and lodging resistance, and 'Ou329', was developed by the rice breeding team of Sangju Substation, National Institute of Crop Science, Rural Development Administration in 2010. This variety has about 120 days growth duration from transplanting to harvesting in southern mid-mountainous area of Korea. It has 78 cm culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows strong resistance to blast and viviparous germination, but is susceptible to bacterial blight, virus diseases, and insect pests. The milled rice of 'Jungmo 1012' exhibit translucent, relatively clear non-glutinous endosperm and medium short grain. It has a little lower amylose content of 18.2%, and higher protein content of 6.3%, and good palatability of cooked rice compared with 'Odaebyeo'. The milled rice yield performance of this variety is about 5.55 MT/ha in local adaptability test for three years. 'Jungmo 1012' will be adaptable to southern mid-mountainous of South Korea.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.149-153
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• 2009

Junamjosaeng is a new japonica rice cultivar developed in 2006 from a cross between Milyang165*3 and Koshihikari at the Department of Functional Crop Science, NICS, RDA. This cultivar is suitable for the double cropping system (i. e., before and after the cash crop). Heading date of Junamjosaeng is 6 days earlier than Keumobyeo under the late transplanting cultivation on July 10. It has a high grain fertility under cold conditions and low premature heading. One of the distinguishing characteristics of this variety is its resistance to major diseases like leaf blast, bacterial blight races ($K_1$, $K_2$, $K_3$) and rice stripe virus disease. However, it showed susceptibility to major insect pests. Milled rice kernels are translucent with non glutinous endosperm and have 6.7% protein and 19.8% amylose contents. Milling recovery of head rice is 75.7%. The palatability of cooked rice is better than Keumobyeo. The milled rice yield of Junamjosaeng in local adaptability tests after harvest of the cash crop was $4.43\;tons\;ha^{-1}$. This cultivar is suitable for planting in the plain paddy fields of Honam and Yeonnam regions in Korea.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.615-622
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• 2010

A new rice cultivar, 'Joami', was developed by the rice breeding team of Sangju Substation, National Institute of Crop Science (NICS), Rural Development Administration. It was selected by a bulk and pedigree methods from a cross-combination among 'Sambaegbyeo', 'Yukara', and 'Tonggae112'. A promising line of YR20557-1-1-3-B-3 was designated as 'Sangju 36' in 2006. Local adaptability test of 'Sangju 36' was conducted at ten sites throughout the Korean peninsula during three years from 2006 to 2008. 'Sangju 36', thereafter, was registered as 'Joami' in 2008. The cultivar headed on July 30 in the test of local adaptability. Endosperm of 'Joami' is translucent with clear chalkiness and has 5.4% higher head rice ratio than that of 'Odaebyeo'. The yield potential of 'Joami' in milled rice is about 5.40 MT/ha under ordinary fertilizer level of local adaptability test, which was 6% higher than that of 'Odaebyeo'. In an alpine area of Korea, the rice variety needs a cold tolerance and a resistance to blast disease. 'Joami' showed a tolerance reaction at Chuncheon cold tolerance screening nursery and exhibited resistance reaction to blast disease in nation-wide disease screening nursery. Therefore, 'Joami' would be well adaptable to mid-mountainous area at central and southern part of Korean peninsula.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.163-167
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• 2009

Jogwang is a new early maturing japonica rice developed in 2007 from a cross between Milyang187 and YR21113-B-B at the Department of Functional Crop Science, NICS, RDA. This cultivar is very suitable to the rice-cash crop double cropping system. Heading date of Jogwang is 2 days earlier than Keumobyeo under the late transplanting cultivation on July 10 at the Yeongnam plain. The tolerance level of this variety to leaf discoloration at seedling stage is very similar to Keumobyeo. It showed slightly lower viviparous germination and premature heading. This cultivar showed resistant reactions to leaf blast and rice stripe virus disease but susceptible to bacterial blight disease and major insect pests. The ratio of milling and head rice recovery of Jogwang is 76.5% and 64.5%, respectively. The milled kernels are translucent with non glutinous endosperm. This cultivar has 7.3% protein and 18.5% amylose content. In local adaptability test, showed that the milled rice yield of Jogwang is $4.90\;MT\;ha^{-1}$. This cultivar is suitable for planting in the plain paddy fields of Honam and Yeonnam regions in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.297-306
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• 2021

To select rice (Oryza sativa L.) cultivars suitable for forage-rice double cropping system, the growth and grain quality of four early maturing rice cultivars (Joun, Jopyeong, Haedamssal, and Unkwang), and the chemical properties of soils were investigated under single- (fallow-rice) and forage-rice double-cropping systems in paddy fields in Miryang, southern Korea. The soil where two forage crops [Italian ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.)] were cultivated during winter had a slightly lower pH; an increase in total nitrogen (T-N), K, Ca, and Na contents; and a slight decrease in organic matter and available P₂O₅ contents, compared with the soil fallowed during winter. This shows that the chemical properties of paddy soils can be improved by winter forage cropping. At the heading stage, the culm length, panicle length, panicle number, and leaf color of all cultivars, except for Haedamssal, were generally higher under double-cropping than under single-cropping. For Haedamssal, the culm length and leaf color did not differ between the cropping systems, but the panicle length was slightly shortened and its panicle number increased under double-cropping. After harvest, the yield of milled rice decreased for all cultivars except Haedamssal, but increased in Haedamssal under double-cropping. The head rice rate was slightly higher under double cropping, particularly in Jopyeong and Haedamssal, than under single-cropping. The protein content of milled rice under double cropping was higher and its amylose content was similar or slightly lower compared to those of rice under single cropping, resulting in decreased Toyo values for rice under double-cropping. The pasting temperature did not differ significantly between the cropping systems. However, Haedamssal had a low pasting temperature but a high Toyo value under double cropping, compared to the other three cultivars, suggesting that its palatability is relatively high. Furthermore, panicle number increased and milled rice yield did not decrease, even under double cropping. Therefore, Haedamssal seems to be the best cultivar for paddy-based double cropping with forage crops.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.139-145
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• 1992

To investigate changes in fatty acid and lipid composition of maturing perilla(Perilla frutescens var. japonica Hara) seeds, Suweon 10 and Jeju varieties were subjected to lipid analysis. The results were summarized as follows; As perilla seeds matured, content of ether-extractable lipids increased continuously to 46.3% in Suweon and 24.0% in Jeju. In ether-extractable lipids of mature perilla seeds, palmitic acid was $9.4{\sim}18.2%$, stearic acid $2.2{\sim}5.1%$, oleic acid $19.1{\sim}32.7%$, linoleic acid $12.4{\sim}15.3%$ and linolenic acid $30.6{\sim}54.1%$ of total fatty acid. Therefore, major fatty acid were unsaturated In mature seeds while those were saturated in the early stage of seed development. As perilla seeds matured, content of neutal lipids in total lipids increased. Neutral lipids of mature seed was 70.1% in Suweon 10 and 51.5% in Jeju, respectively. Triglycerides, free fatty acid and diglycerides were major components of ether-extractable neutral lipids. Triglyceride, which showed relatively rapid increase in the early stage of development, increased to 61.4% in Suweon 10 and 68.2% in Jeju, respectively.