Labor, Seedling Establishment and Yield in Direct Seeding of Non-coated Rice Seeds Using a Puddling Seeder in the Cool Region of Japan

Abstract

Non-coated rice seeds of rice varieties “Moeminori” and “Haenuki” were direct seeded using a trial puddling seeder in a cool region in Japan from 2011 to 2014. The seeder does not require seed coating or the finishing puddling. The time required for seeding was 0.32 hr 10a^-1 on the average with a minimum of 0.22 hr 10a^-1. The percentage of seedling establishment in the field drained after shallow seeding with a puddling seeder was 65%. The seedling distribution was more even in the field in which seeds were sown with the seeder than in the field in which a knapsack duster was used and comparable to that in which iron-coated seeds were sown with a hill seeder. The maximum stem number was larger than the standard value for direct seeding. Dry weight at heading and maturity was similar to the standard value. Lodging was slight in most experiments. Combineharvested yield of “Moeminori” ranged from 573 to 660 kg 10a^-1 and was comparable to that obtained by direct seeding of ironcoated seeds. The yield of “Haenuki” ranged from 480 to 688 kg 10a^-1 and comparable to the average yield in the regions except that in the experiment suffering from heavy lodging and weed infestation. We conclude that the direct shallow seeding of noncoated seeds is useful for rice farmers in the cool region of Japan.