‘Alchanheukchal’ is a single-cross hybrid waxy corn cultivar developed by using the inbred line ‘KBW16’ as the seed parent and ‘KBW23’ as the pollen parent. Yield trials were conducted in 2013 and 2015 followed by regional adaptability tests at six locations over three years (2018-2020). Recognized for its superior performance, it was designated as a new variety by the NICS in 2020. ‘Alchanheukchal’ contains 32.9 μg 100 g^-1 of anthocyanins, resulting in black-colored ears and exhibiting an intermediate ear shape. Its silking period was 74 days, equivalent to that of the standard variety ‘Ilmichal’. The ear length was 19.3 cm, similar to ‘Ilmichal’, while the kernel set rate was 94%, which was lower than that of ‘Ilmichal’. In terms of disease and pest resistance, including southern rust, northern corn leaf blight, and corn borer, as well as lodging resistance, ‘Alchanheukchal’ was comparable to ‘Ilmichal’. The number of ears and ear weight per 10a were 6,336 ears and 1,136 kg, respectively, which indicates a higher ear number but lower ear weight than ‘Ilmichal’. The 100-kernel weight was 27.7 g, smaller than that of ‘Ilmichal’. In sensory evaluation tests, the overall acceptability score was 4.7, which was lower than that of ‘Ilmichal’. The highest seed production efficiency was observed when the planting ratio of the seed parent to pollen parent was 2:1. However, because the silking date of the pollen parent occurred later, it was considered necessary to perform staggered sowing (Registration No. 10033).

‘Godangok 2’, a yellow sweet corn hybrid obtained by crossing inbred KSE14 (female) and KSE23 (male) varieties harboring the sugary enhancer (se) gene, was developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration, Korea, in 2020. Days to silking of ‘Godangok 2’ (65 days) was 3 days later than ‘Danok 3’ (check hybrid, 62 days). The ear length of ‘Godangok 2’ (18.9 cm) was similar to that of ‘Danok 3’, but it exhibited a higher kernel filling rate (97%). In addition, the lodging tolerance of ‘Godangok2’ was greater than that of ‘Danok3’. The number of ears per 10a in Godangok2 (6,177) was 4% higher than that in ‘Danok 3’, whereas ear weights (1,075 kg) were 4% lower. ‘Godangok 2’ had a high sugar content of 23.4° Brix, a thin pericarp thickness of 21.4 μm, and a light 100-kernel weight of 25.4 g compared to that of the check hybrid. ‘Godangok 2’ showed the highest seed yield of 270 kg/10a at a 4 (female):1 (male) planting ratio. Because ‘Godangok 2’ carries the recessive se gene, its unique qualities may be compromised by cross-pollination with other corn varieties (e.g., sh2, bt, wx types). Therefore, to maintain sweet corn quality, corn should be grown and harvested separately in time and space (Registration No. 10059).

‘KM7’, a maize hybrid for grain production, was developed for the Southeast Asian seed market by the maize breeding team of the National Institute of Crop Science (NICS), Rural Development Administration (RDA) in 2020. The hybrid, ‘KM7’, was bred by crossing two inbred lines, CL32 and 14K23. After a one-year yield trial in Dong Trieu, Vietnam, country adaptability trials were performed three times in three different countries (Vietnam, Cambodia, and Indonesia) in both 2019 and 2020. The seed type was flint-like and suitable for both food and feed. ‘KM7’ adapted well to conditions in northern Vietnam, northwestern Cambodia, and Central Java in Indonesia. The silking date of ‘KM7’ in Vietnam was 62 d, which was 1 d earler than that of LCH9, a leading cultivar in Vietnam. ‘KM7’ is an early maturing, high-grain yielding F1 hybrid that is also resistant to downy mildew. ‘KM7’ produced a grain yield of 842, 831, and 950 kg/10a in Vietnam, Cambodia, and Indonesia, respectively. This demonstrated a higher yield than that of the leading cultivars in each respective country. ‘KM7’ produced 26% more grain in Vietnam, 28% more in Cambodia, and 56% more in Indonesia than the respective control varieties (Registration No. 10034).

‘KM3’ is an F1 hybrid maize developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration (RDA), for the Southeast Asian seed market. This hybrid was obtained by crossbreeding two inbred lines—14K26 and 15VL027. The hybrid was evaluated in a crop-year yield trial in Cambodia, followed by country adaptability trials in Cambodia and Indonesia in 2016 and 2017, respectively. The flint-like seed type of ‘KM3’ makes it suitable for both food and feed, demonstrating its adaptability to Southeast Asia. ‘KM3’ exhibited early maturity, high grain yield as an F1 hybrid, and resistance to downy mildew. The silking date of ‘KM3’ was two days earlier than that of the leading cultivar ‘CP888’ in Cambodia, with a grain yield of 913 kg/10a, outperforming ‘CP888’ by 26% (Registration No. 9319).

‘KM5,’ a high grain yielding maize hybrid, was developed for the Southeast Asian seed market in 2018 by the maize breeding team of the National Institute of Crop Science (NICS), Rural Development Administration (RDA). ‘KM5’ was bred by crossing two inbred lines—14K23 and CL59. After a 1-crop year yield trial in Dong Trieu and Vietnam, country adaptability trials were performed in 2017 and 2018 in three different countries—Vietnam, Cambodia, and Indonesia. The seed type is flint-like and suitable for both food and feed. ‘KM5’ adapted well to northern Vietnam, northwestern Cambodia, and Central Java in Indonesia. It is an early maturing, high grain yield F1 hybrid that is also resistant to downy mildew. The silking date of ‘KM5’ in Vietnam is 74 days, which is the same as that of LCH9—a leading cultivar in Vietnam. ‘KM5’ produced a grain yield of 695, 764, and 678 kg/10a in Vietnam, Cambodia, and Indonesia, respectively, thus demonstrating a higher yield than the leading cultivar in each country. ‘KM5’ produced 2%, 27%, and 8% more grain than the respective control varieties in Vietnam, Cambodia, and Indonesia, respectively (Registration No. 8947).

‘KM2’, a maize hybrid grain was developed for the Southeast Asian seed market by the maize breeding team of the Rural Development Administration (RDA), South Korea 2018. ‘KM2’ was bred by crossing two inbred lines, ‘15VL065’ and ‘KS155’. After a advanced yield trial at Dong Trieu, Vietnam, for the first cropping cycle in 2016, country adaptability trials were performed twice in three different countries: Vietnam, Cambodia, and Indonesia, in 2016 and 2017. ‘KM2’, a yellow intermediate seed for food and feed, adapts well to the northern Vietnam, northwestern Cambodia, and Central Java in Indonesia. It is an early maturing high-grain yield F1 hybrid. This hybrid is resistant to downy mildew, but not corn rust. The silking date of ‘KM2’ is 10 days earlier than that of ‘LVN10’, a leading cultivar in Vietnam. ‘KM2’ produced grain yields of 811 kg/10a, 845 kg/10a, and 783 kg/10a in Vietnam, Cambodia, and Indonesia, respectively, showing even higher grain yield than the countries’ respective leading cultivar. ‘KM2’ produced 61%, 17%, and 14% higher grain yield in Vietnam, Cambodia, and Indonesia, respectively, than their respective control cultivars (‘LVN10’, ‘CP888’, ‘P21’) (Registration No. 8192).

‘Hwanggeummatchal’, a yellow waxy corn hybrid obtained by crossing inbred ‘KY37’ and ‘KY29’, was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA, Korea, in 2017. The number of days to silking of ‘Hwanggeummatchal’ was 69 days after planting, 2 days earlier than ‘Ilmichal’ (a control variety). Plant height of ‘Hwanggeummatchal’ was 205 cm, lower than that of the control, and ear height ratio was 49%, which was lower than that of ‘Ilmichal’. Lodging resistance of ‘Hwanggeummatchal’ was similar to ‘Ilmichal’. The fresh ear yields were 6,389 ears in 10 a. The carotenoid content of ‘Hwanggeummatchal’ was 16.4 μg 100 g^-1 fresh weight, which was much higher than that of ‘Ilmichal’. The pericarp thickness was 41 μm. The sensory evaluation value was 5.7, and the flavor was excellent. The flowering period of its parental lines was well matched, and seed production was best at a planting ratio of maternal and paternal lines, 3:1. ‘Hwanggeummatchal’ is suitable to the whole country, except for Jeju-do. Seeds of ‘Hwanggeummatchal’ must be renewed annually because it is a single cross hybrid. If this hybrid is cultivated under high-density conditions, the ear size and the ratio of kernel set length to ear length will be lower than that of standard cultivation. Pest control should be performed for this hybrid because it is susceptible to corn borer (Registration No. 8136).

‘KM1’, a corn hybrid was developed for seed export to Southeast Asia by the maize breeding team of the National Institute of Crop Science (NICS), RDA in 2016. The hybrid ‘KM1’ was obtained by crossing two inbred lines, ‘KS155’ and ‘15VL060’. After yield trials at Dong Trieu, Vietnam for one year, country adaptability trials were subsequently carried out in three countries (Vietnam, Cambodia, and Indonesia) in 2016. ‘KM1’ is a white-yellow and dent-like corn, and the plant adapts to the northern part of Vietnam and northwestern part of Cambodia; and the corn can be used as food and feed. The plant is fast flowering and has strong lodging tolerance and resistance to southern leaf blight and downy mildew. Silking date of ‘KM1’ is 5 days earlier than that of Vietnam’s leading cultivar ‘LVN10’. The grain yield of ‘KM1’ is 879 kg/10a in Vietnam, which is 22% higher than that of LVN10, and 914 kg/10a in Cambodia, which is 5% higher than that of Cambodia’s leading cultivar ‘CP888’. This hybrid requires the implementation of disease control measures because it is susceptible to corn rust. (Registration No. 7507).

Hwangmichal, a yellow waxy corn hybrid, is a single cross hybrid developed in 2014. This hybrid was created by crossing the seed parent KY30 and pollen parent KY9. Hwangmichal has yellow kernels with a conico-cylindrical ear shape. The days to silking of Hwangmichal were similar to that of Ilmichal, a check hybrid. The ear height ratio of Hwangmichal was 50%, which was lower than that of Ilmichal, and its number of tillers was less than that of Ilmichal. The ear size of Hwangmichal was smaller than that of Ilmichal and the kernel set ratio was 89%. Its sensory evaluation was better than that of Ilmichal. The carotenoid content of Hwangmichal was 32.2 µg/g, which was much higher than that of Ilmichal. Lodging resistance of Hwangmichal was better than that of Ilmichal. Although the number of fresh ears of Hwangmichal was more than that of Ilmichal, the weight of fresh ears was lower than that of Ilmichal. The flowering period of its parent lines was well matched and seed production was 3:1 at a planting density of parent lines of more than 2:1. It is adaptable to the whole country except for Jeju-do. The plant variety protection right of Hwangmichal was registered in June 2017, and its grant number is 6728.

‘Daanok’, a new maize F₁ hybrid (Zea mays L.), is developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2013. The high-yielding hybrid, named ‘Daanok’ was bred by crossing between two inbred lines, ‘KS174’ and ‘KS175’. It is a yellow semi-flint maize hybrid (Zea mays L.). After preliminary yield trial and advanced yield trial of Daanok in Suwon for two years, regional yield trial of that was subsequently carried out for evaluation of its growth and yield at three different locations from 2011 to 2013. The silking date of Daanok is earlier than that of the check hybrid, ‘Jangdaok’. The plant height of Daanok is 229cm, similar to Jangdaok, and its ear height ratio is similar with that of Jangdaok.It has resistance to lodging. There are much of the No. of ear per 100 plants. The ear length of Daanok is similar with that of Jangdaok. The weight of 100 seeds of Daanok is the same with that of Jangdaok. It has strong resistance to northern leaf blight (Exserohilum turcicum) and southern leaf blight (Bipolaris maydis). It has strong resistance to ear lot. It has moderate resistance to corn borer. The grain yield (7.34 ton/ha) of Daanok was 23% higher than that of Jangdaok. The seed production of Daanok has gone well due to a good synchronization of flowering period during crossing between the seed parent, KS174, and the pollen parent, KS175, in Yeongwol and F1 seed yield was 2.38 ton/ha. Daanok would be a suitable cultivar to all plain area in Korea.

A ‘Hayanchal95’, a new waxy corn hybrid, is a single cross hybrid developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration(RDA) in 2011. This hybrid was made by crossing between seed parent KW44 and pollen parent KW35. Days to silking of Hayanchal95 was three days earlier than Ilmichal, a check hybrid. Ear length and diameter of Hayanchal95 were 18.3 cm and 4.1 cm, respectively. The ratio of kernel set length to ear length was 90% and lower than Ilmichal. Its quality characteristics like amylopectin content, hardness of kernels, and value of sensory evaluation were not significantly different from Ilmichal except grain length. Resistance to corn borer and lodging tolerance of Hayanchal95 were better than Ilmichal. The number of fresh ears was similar to those of Ilmichal and weight of fresh ears was lower than Ilmichal in regional yield trials (RYT) from 2009 to 2011. Although flowering time of its parent lines was good match during crossing between the seed and pollen parents, seed production was low. It is adaptable to the whole country. Plant variety protection right of ‘Hayanchal95’ was registered in July 2014, and its grant number is 5110.

A single cross hybrid, ‘Godangok’, is a yellow sweet corn developed by the maize breeding team at the National Institute of Crop Science (NICS), Rural Development Administration (RDA) in 2011. This hybrid was produced by crossing between KSE5 and KSE19. KSE5 is a seed parent and KSE19 is a pollen parent of Godangok. Days to silking of Godangok was 3 days later than Danok 3, a check hybrid. Ear length and diameter of Godangok were 17.6 cm and 4.4 cm, respectively. The ratio of kernel set length to ear length was 87.1%. These characteristics of ear were similar to those of the check hybrid. However, the Degree Brix was 24.3 °Bx, higher than the check hybrid, 14.1 °Bx. Lodging tolerance of Godangok was better than the check hybrid. The number and weight of fresh ear of Godangok were similar to those of the check hybrid in regional yield trials (RYT) from 2009 to 2011. Seed production of this hybrid is good due to good match between the seed and pollen parent. It is adaptable to the whole country. Plant variety protection right of ‘Godangok’ was registered in July 2014, and its grant number is 5094.