• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1018-1023
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• 2010

Climatic change was observed and analyzed in view of impacts on agricultural ecosystem, inter alia on rice cropping. The changed climate gave rise to earlier transplanting of rice seedling and later harvest after 40 years. Also phenological change and prolonged growth duration was observed. The meteorological data was selected from the standardized climatological data of 30 year normals of 1960s and 2000s, which were published by Korea Meteorological Administration. Development stages and growing periods of rice crop were compared by analyzing critical and optimum temperatures of each growth stage during these two periods. The first appearance date of $15^{\circ}C$ was ranged from Apr. 29 to May 23 in the year-normals of 1960s and it varied from Apr. 24 to May 16 in the normals of 2000s. The difference of the first appearance date of $15^{\circ}C$ was 0~10 days earlier in the year-normals of 2000s than the 1960s. The last harvesting date was determined to be the last appearance date of mean air temperature $15^{\circ}C$. The difference in the last appearance date of $15^{\circ}C$ was 1 to 13 days later in the year-normals of 2000s than in 1960s. The plant height of a rice variety, Hwayoung-byeo was 101~109 cm in 4 local areas, Seoul, Kangneung, Kwangju and Daegu. The plant height became 1~4 cm taller under warm condition. Rice grain yields estimated with daily weather data for the year-normals of 1960s and 2000s were 453~580 kg $10a^{-1}$ and 409~484 kg $10a^{-1}$ respectively. Rice grain yield of the former period was 50~100 kg $10a^{-1}$ higher than that hat in the later period.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.235-244
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• 2017

'Manbaek' is a bacterial blight resistant mid-late maturing rice cultivar with high grain quality. 'Manbeak' was derived from anther culture using the backcross combination, $Hopum^*2/SR30075$. 'Hopum' is a mid-late maturing rice cultivar with high grain quality and 'SR30075' is a pyramid line carrying three bacterial blight resistance genes. 'Manbaek' was selected through the pedigree method, yield trials, and local adaptability tests. 'Manbeak' carrying two bacterial blight resistance gene Xa3 and xa5 showed high-level and broad-spectrum resistance against bacterial blight. 'Manbaek' was resistant to K3a, mostly virulent race in Korea, and exhibited resistance reaction against 16 Korean bacterial blight isolates. 'Manbaek' was a mid-late maturing rice. The heading date of 'Manbaek' was August 19th, which was 5 days later than that of 'Nampyeong'. Manbaek' was a lodging-tolerant rice with short culm and dark green leaf. Due to the low viviparous germination, 'Manbaek' could be a useful material to prevent pre-harvest sprouting. 'Mabeak' was resistant to bacterial blight and rice stripe virus, but susceptible to other virus diseases and insect pests. The yield of 'Manbaek' was similar to 'Nampyeong'. 'Manbaek' showed excellent grain appearance and good tastes of cooked rice, so that it could contribute to improving the quality of bacterial blight resistant cultivars. 'Manbaek', bacterial blight resistant cultivar with high grain quality, is suitable for the cultivation at bacterial blight prone area and has been utilized in the breeding programs for enhancing the resistance against bacterial blight (Registration No. 6069).

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.595-599
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• 2011

'Goami 3' is a new japonica rice cultivar developed from a cross between Suweon464 and Daeanbyeo by the rice breeding team of National Institute of Crop Science, RDA. 'Goami3' has about 130 days growth duration from transplanting to heading in central plain area of Korea. It has a good semi-erect plant type and resistance to lodging of about 79 cm in culm length. 'Goami 3' had 15 panicles per hill and 104 spikelets per panicle. 'Goami 3' has very high amylose (29.5%) and high non-dietary starch compared with Hwaseongbyeo. This rice variety has slow senescence and 47% tolerance to viviparous germination during the ripening stage. 'Goami 3' is susceptible to leaf blast, bacterial blight, virus disease and insect pest. The yield performance of this cultivar in milled rice was about 3.92MT/ha by ordinary season culture in local adaptability test from 2005 to 2007. 'Goami 3' is adaptable to central and southern plain area of Korea.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.600-605
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• 2011

'Boseogheugchal', a new black pericarp glutinous rice cultivar (Oriza sativa L.), was developed by the rice breeding team of National Institute of Crop Science, RDA, Suwon, Korea during the period from 1997 to 2008 and released in 2008. It was derived from a cross between SR18638-B-B-B-18-2/ Heugmi H31. The maturity of this cultivar is about 135 days from seedling to heading. This cultivar has about 12 tillers per hill and 94 spikelet numbers per panicle. Ripening ratio is about 72% and 1000 grain weight is 21.6 g in brown rice. This new variety shows grain shattering resistance and susceptible for blast, bacterial leaf blight and stripe virus. 'Boseogheugchal' has glutinous endosperm and low protein contents. It has higher anthocyanin content compared to black pigmented check cultivar 'Hegjinjubyeo'. The yield performance of brown rice was 4.82 MT/ha in local adaptability test for three years. 'Boseogheugchal' is adaptable to central plain area of Korea.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.543-548
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• 2011

Haiami is a new Japonica rice variety developed from a cross between 'Jinmibyeo' TR treated with ethyl methane sulfonate (EMS) EMS and 5-methytryptophan, and 'Gyehwabyeo' in order to develop a new premium quality rice variety by a rice breeding team of National Institute of Crop Science, Rural Development Administration in 2008. This variety has about 138 days of growth duration from transplanting to harvesting in central plain area of Korea. The heading date of this vareity was on $15^{th}$, August. The 'Haiami' has good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Haiami' is more than that of 'Hwaseongbyeo'. This variety shows slow leaf senescence and considerable tolerance to viviparous germination. It is susceptible to leaf blast, bacterial blight, and insect pests, but resistance to rice stripe virus. The milled rice of this variety exhibited translucent, clear non-glutinous endosperm and short grain shape. The essential amino acid properties of 'Haiami' have more than 31% that of 'Hwaseongbyeo' in polished rice. This variety has premium palatability of cooked rice. The yield performance of this rice cultivar was about 5.38 MT/ha in milled rice in local adaptability test for three years from 2006 to 2008. 'Haiami' is adaptable to central and southern plain areas of Korea.

• Korean Journal of Breeding Science
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• v.51 no.3
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• pp.222-233
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• 2019

'Haepum' is a bacterial blight-resistant, medium maturing rice cultivar with high grain quality. It was derived from a cross between 'Iksan493' (cultivar name 'Jinbaek') and the F₁ cross between 'Iksan495' ('Dacheong') and 'Iksan496' ('Jungmo1005'). Of these three cultivars, 'Jinbaek' is a bacterial blight-resistant mid-late maturing rice cultivar with high grain quality, 'Dacheong' is a mid-late maturing rice cultivar with multiple resistance to disease and insects, and 'Jungmo1005' is a mid-late maturing rice cultivar with lodging tolerance. To develop fixed lines, the anther culture method was applied to F₁ plants. The cultivar 'Haepum' was selected using the pedigree method, yield trials, and local adaptability tests. The heading date of 'Haepum' was August 11^th, three days earlier than that of 'Nampyeong' cultivar. Haepum' is a cultivar tolerant to lodging and it has short culms. Due to its low rate of viviparous germination, 'Haepum' could be useful for preventing pre-harvest sprouting in cultivation of medium maturing rice in the southern plain area of Korea. 'Haepum' carries two bacterial blight resistance genes (Xa3 and xa5), and in our study, it exhibited high-level and broad-spectrum resistance against bacterial blight, including K3a, the most virulent race in Korea. 'Haepum' is also resistant to the rice stripe virus and moderately resistant to rice blast. The yield of 'Haepum' was similar to that of 'Nampyeong'. 'Haepum' showed excellent grain appearance and good taste of cooked rice, and therefore it could contribute to the development of bacterial blight-resistant rice cultivars of improved quality. 'Haepum' would be suitable for cultivation in the southern plain area of Korea as well as in bacterial blight-prone areas. (Registration No. 6068)

• Korean Journal of Breeding Science
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• v.51 no.4
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• pp.504-514
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• 2019

'Yechan' is a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance. It was a derived from a cross between 'Hopum' and 'Iksan537' (cultivar name 'Haepum'). 'Hopum' is a high grain quality mid-late maturing rice cultivar with strong lodging tolerance and 'Haepum' is a high grain quality medium maturing rice cultivar with multiple disease resistance. To shorten the breeding period, another culture method was applied to the F₁ plants. 'Yechan' was selected through the pedigree method, yield trials, and local adaptability tests, with a high selection pressure for grain quality, lodging, and disease resistance. The heading date of 'Yechan' was August 14, one day later than that of 'Nampyeong'. 'Yechan' is a cultivar tolerant to lodging and it has short culms. It has multiple disease resistance against rice blast, rice stripe virus, and bacterial blight, including the K3a race, the most virulent race in Korea. The yield of 'Yechan' was similar to that of 'Nampyeong'. 'Yechan' showed excellent grain appearance, superior taste when cooked, and enhanced milling performance; thus, we concluded that it could contribute to the improvement of Korean japonica rice cultivar quality. 'Yechan', a high grain quality mid-late maturing rice cultivar with lodging tolerance and multiple disease resistance, would be suitable for cultivation in the southern plain area in Korea and has been utilized in the breeding programs aimed at enhancing the grain quality and stability for the cultivation of Korean japonica rice (Registration No. 7647).

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.356-369
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• 1985

In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.654-659
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• 2009

"Cheongcheongjinmi" is a new japonica rice variety developed from a cross between Iri401 and Ilpumbyeo by the rice breeding team of National Institute of Crop Science, RDA. This variety is suitable for ordinary season culture of low level nitrogen application. Heading date of "Cheongcheongjinmi" is August 17, 4 days later than that of Sobibyeo in plain areas. It has culm length of 82 cm, and relatively semi-erect pubescent leaf blade and slightly tough culm tolerant to lodging with good canopy architecture. This variety has 13 tillers per hill, 126 spikelets per panicle and 90.2% of ripened grains. "Cheongcheongjinmi" showed lower spikelet fertility than Sobibyeo when exposed to cold stress. This variety showed slower leaf senescence and lower viviparous germination compared to Sobibyeo during the ripening stage. "Cheongcheongjinmi" is susceptible to blast disease, bacterial blight, virus diseases and planthoppers. The dried plant weight, total nitrogen and RuBisCO activity of "Cheongcheongjinmi" were higher than those of Sobibyeo in low level nitrogen application. The milled rice of "Cheongcheongjinmi" exhibits translucent, clear non-glutinous endosperm and medium short grain. It shows lower protein and amylose contents than those of Sobibyeo, and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.10 MT/ha at low level nitrogen application of ordinary season culture in local adaptability test for three years. Especially, "Cheongcheongjinmi" has better milling properties such as the percentage of whole grain in milled rice and milling recovery of whole grain, respectively than those of Sobibyeo. "Cheongcheongjinmi" would be adaptable to middle plain areas and middle-western coastal areas of Korea.