Abstract
The emergence and establishment of germinated iron oxide-coated paddy rice seeds were examined in the field and in pots to establish a method for direct seeding culture of iron oxide-coated seeds using an air-assisted row seeder in a cold districts. In this study, we focused on the prewarming of coated seeds to shorten the time to seedling emergence and establishment of direct seeding of iron oxide-coated germinated seeds. The effect of seeder passage treatment after heat processing of coated seeds on seedling emergence and establishment and that of cold storage of coated seeds were examined. Direct seeding of iron-coated germinated seeds resulted in earlier seedling emergence and higher establishment rate and promoted early growth under low temperature conditions, suggesting that iron oxide-coated germinated seeds would perform well in cold areas such as Hokuriku region. However, iron oxide-coated germinated seeds, after prewarming were markedly damaged by seeder passage treatment and were rapidly deteriorated in germinability during low temperature storage. Overall, the introduction of prewarming of coated seeds into direct seeding culture of iron oxide-coated seeds was difficult.
