"Oraebyeo" is mutation of a high quality japonica cultivar, Ilpumbyeoa new japonica rice(Oriza sativa L.) cultivar developed from by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res. & Ext. Service in 2006. This variety heads 20 days earlier than Ilpumbyeo and similar to that of Odaebyeo an early maturing leading cultivar of northern plain area of Korea. Compared with Odaebyeo has a good semi-erect plant type with lodging tolerance due to much shortened plant hight(l2cm shorter than Odaebyeo). Oraebyeo has similar panicle number with Odaebye where as it has more spikelets per panicle. However, this variety less the ratio of ripened grains and 1,000 grain weight than those of Odaebyeo. The yield performance of this cultivar in milled rice was about 5.09MT/ha in local adaptability test conducted for three years 2002-2004 and 5.51MT/ha in the demonstration plot of farmer's field.

Sanggolbyeo is a new japonica rice cultivar developed from Ilpumbyeo mutation lines by N-methyl-N-nitrosourea(MNU) treatment on fertilized egg cell by the rice breeding team of Gangwon Provincial Agricultural Res.& Ext. Service in 2006. This cultivar has about 135 days growth duration from transplanting to harvesting. Sanggolbyeo has short and round grain and non-glutinous endosperm with very low phytate content, below 50% of Ilpumbyeo, implying it could help men to absorb Calcium from rice. This cultivar shows midium diseases tolerance to leaf blast, bacterial blight, virus and insect pest. The milled rice yield of Sanggolbyeo is about 4.98 MT/ha at ordinary transplanting culture in the local adaptability test. Sanggolbyeo would be adaptable for the mid-northern plain areas of Korea.

Expanded rice husk (ERR) is different from commercial rice seedling media in chemical and physical properties such as pH, permeability, and water content. This study was conducted to test a possibility of improving rice seedling growth by improving the texture of ERR as a rice seedling medium. The seedling media used were a commercial seedling medium (CSM), rice husk, and ERR 1, 2, 3, and 4 with different expansion degrees. The pH of the ERHs ranged from 6.3 to 6.8. As the expansion rate increased, ERR particle sizes decreased, and water permeability and absorption rates improved. No significant differences in shoot dry weight and rate of maturity were found among the seedlings cultivated in the different ERH media. However, the mat formation of seedling roots became loose as the expansion rates were decreased. Further studies are necessary to determine the cause of poor root growth in ERH media.