Kyungpook National University

The Academy of Agricultural Sciences

Progress of maize breeding and production increase in North Korea

--Kim, SK, Han, HJ, Kim, P

Maize is a staple food crop in North Korea, along with rice. It is grown on approximately 700,000ha, with about 200,000ha being on the hilly side, and rice is grown on 600,000ha. Seventy percent of the population of 23 million North Koreans depends on maize as the main food. While South Korea, with a population of 47 million, is the second largest importer of maize in the world after Japan. Historic floods in 1995 and 1996, and hail and drought in 1997, along with economic difficulties, caused the country of North Korea to be at the center of world concern. When the country had severe economic difficulties, scientists of South and North Korea, with strong support from both governments, and Koreans inside and outside of Korea, agreed to increase maize production in the shortest possible time, and also develop better high yielding and more stable maize cultivars for the country. The major constraints in maize production were lack of fertilizers and high quality F1 seeds, and the solid cropping of maize with legumes. The North and South Korean team collaborating on super-maize research has taken two prolonged approaches: increase grain production with the hybrid Suwon 19, which was developed in South Korea in 1976 by the senior author after his education in the USA, and initiate an extensive maize breeding program nationwide. The results of six years of the collaborative works (1998-2003) show that North Korea has very favorable environments for maize cultivation. The total production of maize and other foods (rice and potato) has increased from two million tons to four million tons within the project period. Purity improvement of the F1 hybrid, intercropping of soybean into maize fields, reduction of the population density of maize plants, and increased availability of fertilizers were aided by the government of South Korea as well as by NGOs. The increase in total production was also influenced by the promotion of disease free potato seeds and the advancement of agriculture as the No.1 policy of the government, as well as the introduction of the bonus system to encourage more cooperative farms. Although the total production has been doubled, it is still short one million tons for the population size. Approximately half of the 3000 cooperative farms have used Suwon 19 for grain production. The collaborative team has tested a total of 31,000 crosses at 25 stations in North Korea and 7 in South Korea. Ten outstanding hybrids have been selected from the on-farm testings. F1 seed production for larger scale testings has been carried out. The results of genetic studies for tolerance of new maize inbreds to major biotic (Exserohilum turcicum, stalk rots, stem borers) and abiotic stresses (drought and N use efficiency) will increase the stability of maize.