The Investigations and the Improvement of Problems which are Admitted on the Rasing Method of Rice Seeding by Sparse Seeding with No-heating in the Northen Area of Japan

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 04556003
• Research Category: Grant-in-Aid for Developmental Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 作物
• Research Institution: Miyagi Agricultural College
• Principal Investigator: SAITO Mitsuo Miyagi Agri. College, Agriculture, Assistant Professor, 農業科, 助教授 (50196010)
• Co-Investigator(Kenkyū-buntansha): GOTO Yusuke Tohoku University, Faculty of Agriculture, Assistant, 農学部, 助手 (80122919) ; TOGASHI Chiyuki Miyagi Agri. College, Agri. Ebgineering, Assistant Professor, 農業土木科, 助教授 (00105181) ; MATSUMORI Kazuhiro Miyagi Agri. College, Agriculture, Instructor, 農業科, 講師 (00181793)
• Project Period (FY): 1992 – 1994
• Keywords: Mature seedling / Permissible rate of vacant hills / Raising of seedling by sparse seedling with no-heating / Raising rice in the northern area of Japan / Seeded accuracy / Seeded style in the mursery box / Sparse seeding / The tiller from the 2nd node

Research Abstract

The rasing method of rice seedlings which was based on sparse seeding with no-heating is adapted by the devoted farmer in the northern area of Japan.
After advantages and disadvantages of this rasing method had been made clear, improvements of this method and the management works on paddy fields were tried. When the seeding rate per nursery box was about 40g which was less than half of it to get middle ssedling, the tiller from the 2nd node (T2) was secured over 80% of seedling at 6-leaf age. When these seedlings were transplanted to the paddy field, almost every T2 became productive tiller, and it contributed to get a lot of panicle number and yield. This kind of seedlings could be got by other two ways. One was heating the nursery box in the nursery chamber which had been kept at 32ﾟC for the next day after seeding. The other was heating it in the same condition's nursery chamber and lighting it at second day after seeding. When two mature seedlings which had tiller were transplanted as one hill, artificial vacant hills were occurred. As the result of it, compensatory effect was admitted on hills around the vacant hill. The vacant hills' rate which did not influence to yield (permissible rate of vacant hills) was 20%, and if continuous 2-or-3 vacant hills had been occurred, it was 10 to 8%. When the seeding rate per nursery box was about 40g, seeding accuracy was worse by the broadcast seeding with hand. And vacant hills were occurred over the permissible rate of vacant hills. Two types of seeders for mature sedling were useful. But vacant hills' rate by using transplanter was higher than the theoretical rate which was counted by using those seeder. When it was considered that the vacant hills and the situation that was the one nursery seedling was transplanted as one hill, countermeasure was necessary for high seeding accuracy.