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).

Early maturing rice cultivars grown in plain areas have an undesirable appearance due to high temperatures during the grain-filling stage. Therefore, developing early maturing rice cultivars with desirable appearance traits in plain areas is the primary goal of rice breeding programs. This study aimed to develop an early maturing rice cultivar adaptable to early transplanting cultivation in the Chungnam plain area. To develop “Yeoreumi,” two breeding materials were used, good-quality “Joami” from the Chungnam plain area and “Hokuto” having the fastest heading date among the genetic resources and originating from Japan. These two resources were crossed in 2010 to develop the “Yeoreumi” cultivar using the pedigree method. A yield trial was conducted in 2015-2016, and a local adaptability test was conducted in 2017-2019. The heading date of “Yeoreumi” was July 10, when it was transplanted early in the Chungnam plain area, and it could be harvested at August end, which was sufficient to produce a fresh stock of rice before “Chuseok, which is the Korean Thanksgiving Day.” The yield of milled rice was approximately 5.29 MT/ha in the local adaptability test, which was 0.47 MT/ha higher than that of “Jinbuolbyeo.” Additionally, its grain quality was good, with 89.9% head rice and 67.6 glossiness of cooked rice. Overall, the results of this study indicated that “Yeoreumi” was suitable for early transplanting cultivation in the Chungnam plain area for “Chuseok,” and could be used as a representative early maturing rice cultivar in Chungcheongnam-do (Registration No. 8597).

This study was performed to determine the optimum transplanting dates of ‘Bbareumi’ in the Chungnam Plain area. ‘Bbareumi’ was transplanted into a rice research field of Chungnam Agricultural Research and Extension Services at intervals of approximately 15 days from April 17^th to August 1^st in 2019 and 2020. The heading dates of ‘Bbareumi’ were June 23^rd to September 2^nd depending on transplanting dates. The highest milled-rice yield was 5.61 MT/ha on May 1^st and the lowest was 3.65 MT/ha on August 1^st. As the transplanting date was delayed, protein content increased; however, the number of days from transplanting to heading decreased. Protein content and the number of days from transplanting to heading showed a highly significant correlation (R² = 0.802^**). Therefore, it was found that early transplanting was beneficial to produce lower protein content because head rice percentage was 84-87% for early (April 17^th to May 16^th), 74-80% normal (June 1^st to June 16^th), and 86-95% for the late transplanting date (July 1^st to August 1^st). The mean temperature during the ripening stage differed according to the transplanting dates, and early transplanting showed a lower temperature than the normal one (May 16^th to June 15^th) and a higher head rice percentage. Therefore, extremely early maturing rice cultivars should be transplanted between late April and early May to obtain lower protein content and higher head rice percentage. These results will be useful for rice breeding programs, as it is generally recognized that early transplanting results in poor rice quality; however, this study revealed contrasting results.