단미벼의 발아 특성 및 기계이앙 육묘시 적정 파종량
Studies on Seed Germination Characteristics of Rice Cultivar ‘Danmi’ and Its Optimum Seeding Rates for Seedling Raising in Machine Transplanting
A high sugar rice cultivar Danmi which has been recently developed and released in the Functional Crop Resource Development Division, Department of Func-tional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed develop-ment. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of ‘Danmi’ and determined an optimum seeding rate for seedling establishment. Danmi seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo s 26.7g. The 97.4% of ‘Danmi’ seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed ger-mination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of 20-31℃ because of high seed amount of specific gravity below 1.0 in Danmi . It took 2~4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. ‘Danmi’ has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of Danmi in the seedbed was 62.6~64.9% for 10-day old seedling and 83.5~86.7% for 30-day old seedling which is lower by 29.6~30.0% and 11.3~12%, respectively than Ilmibyeo. Although Danmi has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of ‘Danmi’ for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.
재료 및 방법
결과 및 고찰