Developing a unique local variety that adapts well to the regional environment and consistently expresses its own characteristics provides a significant competitive advantage in the branded rice market. The aim of this study was to develop a Mid-Late Maturing Rice Cultivar with High Grain Quality adapted to the Chungnam Plain. ‘Daebang’ was developed by crossing ‘Haedamssal,’ a stable and high-yielding cultivar, with ‘Jinsumi,’ known for excellent grain appearance and eating quality, during the winter of 2013-2014. The F₁ was grown in summer 2014 to produce F₂ seeds, and promising lines were selected via the pedigree method. Under normal transplanting, ‘Daebang’ headed on August 19, about four days later than ‘Samkwang. ’ It had a culm length of 75 cm (9 cm shorter than ‘Samkwang’), indicating better lodging resistance. It had 84 spikelets per panicle, a 1,000-grain weight of 21.9 g, and a milled rice yield of 6.06 MT ha^-1, which was numerically higher but not significantly different from that of ‘Samkwang.’ The head rice ratio was 95.9%, with a protein content of 5.4%, and glossiness value 78.5, indicating a superior grain quality. ‘Daebang’ also showed similar resistance to blast and bacterial leaf blight as ‘Samkwang.’ Therefore, ‘Daebang’ is expected to serve as a promising mid-late maturing cultivar for producing premium-branded rice in the Chungnam region because of its high grain quality, lodging tolerance, and stable yield (Registration No. 9169).

The rice cultivar, ‘Dapum’, is a high-quality, late-maturing rice with low amylose content developed by the Chungcheongnam-do Agricultural Research and Extension Services (Yesan, Korea). Dapum was derived from a cross between Miho, a processed rice cultivar known for its cultivation stability and low amylose content, as the maternal parent, and Daohuaxing2, a high-quality aromatic rice cultivar, as the paternal parent. Subsequently, a pedigree breeding method was employed, and yield trials conducted from 2019-2020, followed by local adaptability tests from 2020-2021. As a result of the local adaptability test, the heading date of ‘Dapum’ was August 28^th, which is slower than the cultivars mainly cultivated in the Chungnam Province in Korea; therefore, it can be ripened at an appropriate temperature. The yield of milled ‘Dapum’ rice under standard fertilizer conditions was approximately 572 kg/10a, which was 15 kg/10a higher than that of Miho. The amylose content of ‘Dapum’ was 12.5%, similar to that of Miho, and the glossiness of cooked rice, which reflects its indirect eating quality, was 86.8, which was 7.0 points higher than that of Miho. The new rice cultivar, ‘Dapum’, is expected to be used in various ways, such as for cooked and processed rice, due to its low amylose content and good eating quality. Further, it has the potential to enhance the competitiveness of rice production in the Chungnam Province by diversifying the rice market, which has traditionally focused on mid-maturing, non-glutinous rice (Registration No. 10181).

The rice cultivar ‘Baekokhyang,’ a high-quality late maturing aromatic rice developed by Chungcheongnam-do Agricultural Research and Extension Services, was developed to cope with rising temperatures due to global warming and the market demand for various rice cultivars. ‘Baekokhyang’ was derived from a cross between ‘Ungwang,’ a multi-disease-resistant early-maturing rice cultivar as the maternal parent, and ‘Okhyangheugchal,’ an aromatic black rice as the paternal parent. Subsequently, a pedigree breeding method was used and yield trials were conducted from 2017 to 2018, followed by local adaptability tests from 2018 to 2019. ‘Baekokhyang’ is a late-maturing rice cultivar with the heading date of August 25th, demonstrating a slower maturation tendency compared to other medium-maturing cultivars, and this trait enables it to be ripened at an appropriate temperature after the heading date. ‘Baekokhyang’ exhibited tolerance to lodging, indicating high cultivation stability and more grains per panicle than ‘Samgwang. ’ Yield of milled rice was approximately 6.42 MT/ha under normal fertilizer levels in the local adaptability tests, which was 0.38 MT/ha higher than that of ‘Samgwang’. Additionally, the weight of 1,000 brown grains was 26 g which was 4.4 g heavier than that of ‘Samgwang’. The width/length ratio was 1.97, indicating the characteristic of long grains.The new rice cultivar ‘Baekokhyang’ is expected to enhance the competitiveness of rice production in Chungnam Province by diversifying the rice market which is currently dominated by non-glutinous and short-grain rice (Registration No. 8608).

‘Aram’ is a high-quality, medium-late maturing rice variety adapted to the Gyeongnam province. It was developed through a cross between, ‘Yeonghojinmi,’ a good quality cultivar, and ‘Saenuri,’ a disease-resistant cultivar, in 2016. Anther culture was used for developing ‘Aram’. Its average heading date was August 16, which is 2 days later than that of the check cultivar, ‘Nampyeong’. The culm length of ‘Aram’ was 82.3 cm, and it had 17 panicles per hill. The ratio of ripened grain was 85%, which was 3% higher than that of ‘Nampyeong’. ‘Aram’ shows resistance to bacterial blight and rice stripe virus and moderate resistance to bakanae disease. However, it is susceptible to the K3a race of bacterial blight, other viral diseases, and plant-hoppers. ‘Aram’ has strong resistance to viviparous germination (4.9%) before harvest, and it shows strong resistance against field lodging. ‘Aram’ has a milling ratio of 74.6%; in addition, it has a high head-rice ratio and Toyo value. In the sensory test of cooked rice, ‘Aram’ had better scores for grain appearance, texture, and other items, compared to that for the check cultivar, ‘Nampyeong’. Therefore, ‘Aram’ could be used as a raw material for brand rice in Gyeongnam province because of its improved production stability and high quality (Registration No. 9628).

‘Dabokchal, a glutinous rice variety (Oryza sativa L.) with a medium late maturation period was developed by the Department of Crops and Food, JARES in 2020. It was derived from a cross between the glutinous cultivar ‘Shinmyeongheugchal’ with the good glutinous properties and ‘Hwangkumnodeul’ as a high yielding source. The progenies of the cross were selected by bulk and pedigree breeding method until the F₈ generation. As a result, a promising line, JR53-28-4-10-5-3, was advanced and designated as the name of ‘Jeonbuk12’ in 2018. The ‘Jeonbuk12’ local adaptability test was carried out at four locations during 3 years from 2018 to 2020. This variety headed on August 13, which was eight days later than ‘Sinseonchal’ in Honam plane. The culm and panicle length of this variety was 70 cm and 22 cm, respectively. This variety has about 16 tillers per hill and 92 spikelets per panicle. The ratio of ripened grain is approximately 84.9% and 1000-grain weight was 24.9 g in brown rice. This variety has a higher amylose content compared to that of ‘Sinseonchal’. The yield performance of brown rice was 591 kg/10a in the local adaptability test. This cultivar is considered to be adaptable to the Honam plain area of Korea (Registration No. 9602).

This study was conducted to reset the transplanting period to produce high-quality rice in the South regions due to the rise in air temperature caused by global warming. From May 15 to June 25, transplants were performed five times every ten days. Quantity and quality were comprehensively reviewed, including watering season, ripened grain rate, head rice rate, head rice yield, protein content, and palatability. In the southern plains, medium-late and medium maturing cultivars yielded the most when transplanted on June 15, while early maturing cultivars yielded the most when transplanted on June 25. Considering the quality and quantity of rice, the optimal transplanting window for medium-late maturing cultivars is June 10-15, for medium maturing cultivars it is June 15-20, and for early maturing cultivars it is June 25. In the middle of the southern region, the highest yield was on June 25 for medium-late maturing and June 15 for medium maturing and early maturing. However, considering the quality, the best time for transplanting is June 10 for medium-late maturing, June 5 for medium maturing, and June 15 for early maturing. As a result of the rise in average temperature, the transplantation period was delayed by at least 4 to 16 days in all varieties and regions relative to the traditional transplantation duration. In summary, it is determined that a suitable transplanting period must be established in response to the increase in average temperature to ensure the production of high-quality rice.

‘Sangbo’ is a japonica rice (Oryza sativa L.) variety with high head rice grain ratio and good ripened grain color, as well as resistance to rice dwarf virus (RDV) and bacterial blight disease (BB). It was developed by the rice breeding team of the Yeongdeok Branch of the National Institute of Crop Science, RDA, Korea, in 2015. This variety was derived in the 2002 summer season from a cross between ‘Yeongdeog32’, with high eating quality, and ‘Nampyeong’, with a high milling ratio. In 2012, a promising line, YR24256-142-5-3-1-1-2, selected by the pedigree breeding method, was designated the name, ‘Yeongdeog59’. After performing a local adaptability test at nine locations from 2013 to 2015, ‘Yeongdeog59’ was released with the name ‘Sangbo’ in 2015. ‘Sangbo’ has a culm length of 77 cm and a medium-late growth duration. This variety was resistant to K1, K2, and K3 races of bacterial blight, along with the dwarf virus, and was moderately resistant to leaf blast disease. Based on the results of a panel test, ‘Sangbo’ has translucent and clear milled rice kernel without white core and belly rice, and good eating quality. The yield potential of ‘Sangbo’ in milled rice was approximately 6.21 MT/ha at the ordinary fertilizer level of the local adaptability test (LAT). This cultivar would be adaptable to the middle plain, south plain, Yeongnam plain, east coastal area, and south mid-mountainous areas of Korea (Registration No. 7284, 2018.06.25).

Oryza sativa ‘Sinbo’ is a cultivar of japonica rice with good eating quality as well as resistance to rice dwarf virus (RDV) and bacterial blight disease (BB). It was developed in 2013 by the rice breeding team of Yeongdeok Branch, National Institute of Crop Science, RDA, Korea. This cultivar was derived from a cross between ‘Yeongdeog34‘, a cultivar with good eating quality, and ‘Saekyehwa’, a cultivar of a good plant type, in summer of 2002. A promising line (YR24264-25-3-2) selected using the pedigree breeding method was designated as ‘Yeongdeog55’ in 2010. After carrying out the local adaptability test at nine locations from 2011 to 2013, ‘Yeongdeog55’ was published under the name of ‘Sinbo’ in 2013. ‘Sinbo’ is a medium-late maturing cultivar with a short culm length of 70 cm. This cultivar is resistant to K1, K2, and K3 races of bacterial blight as well as to dwarf virus, and it is moderately resistant to leaf blast disease. The results of the panel test indicated that ‘Sinbo’ has translucent and clear milled rice kernel without white core and belly rice as well as good eating quality. The yield potential of ‘Sinbo’ was approximately 5.67 MT/ha at the ordinary fertilizer level in the local adaptability test (LAT). This cultivar could be adaptable to the middle plain, south plain, Yeongnam plain, east costal area, and south mid-mountainous area of South Korea. (Registration No. 5643)

‘Neugeunsuperjami’, a late maturing and blackish purple pigmented rice cultivar, was developed from a cross between Gumjeongbyeo and Hwaseonchalbyeo. During selected by pedigree breeding method until F⁸ generation, a promising line, SR28757-22-2-4-2-1-1-2-B, was selected and advanced by late maturing and content of Cyanidin 3-glucoside. Advance line designated as the name of ‘KNOU 13’. This variety headed on August 28, 140 days to heading after sowing. The culm length and the panicle length of ‘Neugeunsuperjami’ was 91.0 cm and 20.0 cm, respectively. The number of panicle per hill was 10.5 and the number of grain per panicle was 88.6. The dehulling recovery of ‘Neugeunsuperjami’ was about 80.5% and 1,000-grain weight was about 19.7 g, heavier than that of ‘Heugjinju’. ‘Neugeunsuperjami’ has 3~5 times higher Cyanidin-3-glucoside(C3G) content compared with ‘Heugjinju’.

Recently, concerns have been voiced about the high eating quality rice in the market. To cope the high quality demands in rice market, a rice cultivar ‘Jinsumi’ which is showing high grain quality and multi-resistant to diseases was developed by the National Institute of Crop Science, RDA, Miryang, Korea. ‘Jinsumi’ was derived from a three-way cross of ‘Milyang165’ and F1 plant of YR16195-B-B-B-21-1/Milyang169. The pedigree of ‘Jinsumi’ was YR21999-B-B-B-17-3-1 and designated as ‘Milyang 218’ in 2005. Heading date of ‘Jinsumi’ was August 15 as mid-late maturing ecotype. ‘Jinsumi’ showed multi resistant to rice stripe virus (RSV), bacterial blight races of K1, K2, K3 and moderately resistant to leaf blast disease. The grain appearance of ‘Jinsumi’ was translucent and showed 96.6% of head rice ratio. The milled rice yield of ‘Jinsumi’ was 5.74 MT/ha at ordinary transplanting of local adaptability test. ‘Jinsumi’ would be adaptable to the plain area of Yeongnam province in Korea.

The ‘Jungmo1017’ is a japonica rice variety developed from a cross between Suweon462 which has a good plant architecture, cold tolerance, moderately tolerant to leaf blast and bacterial blight and medium maturing habit, and Yeongdeog34 which has translucent milled rice and good milling properties, by the rice breeding team at NICS, RDA in 2011. The heading date of ‘Jungmo1017’ is August 16 and it is six days later than ‘Hwaseong’. ‘Jungmo1017’ has 65 cm of culm length which is 18 cm shorter than those of ‘Hwaseong’ and 93 spikelet per panicle. The pre-harvest sprouting rate of ‘Jungmo1017’ is 8.6% that is lower than 27.7% of ‘Hwaseong’ on local adaptability test (LAT). It showed resistance to blast diseases and moderately resistant to bacterial blight (K1 race) and stripe virus, but susceptible to other races (K2, K3 and K3a) of bacterial blight, viruses and planthoppers. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and medium short grain shape. It has better palatability index of cooked rice (0.53) than that of ‘Hwaseong’. ‘Jungmo1017’ showed lower protein content (6.4%) and amylose content (18.0%). ‘Jungmo1017’ could use aseptic-packaged cooked rice or processing cooked rice because its hardness of cooked rice is soft, setback and balance is low and palatability of cold and aseptic rice showed high score. The characters related to milling is better than those of ‘Hwaseong’. ‘Jungmo1017’ showed 5.01 MT/ha of milled rice productivity at 7 sites of middle plain, southern mid-mountainous and south-east coastal area in ordinary cultivation. ‘Jungmo1017’ could be adaptable to the middle plain area in Korea.