Dry Matter Production and Grain Yield of High Yielding Rice Cultivar, Takanari, Directly Seeded in the Paddy Field with an “Air-assisted Drill”

Abstract

The lodging-tolerant rice cultivar, Takanari, was directly seeded with an “air-assisted drill” in the paddy field, and its dry matter production and grain yield were compared with those in the plants, hill-seeded and conventionally transplanted in 2009, 2010 and 2011. In the air-assisted drilled rice, plants were scattered around the row, which was quite different from the hill-seeded rice. The air-assisted drilled rice produced heavier dry matter and had a higher grain yield than the hill-seeded and transplanted rice, because of the higher crop growth rate. During the tillering stage, tiller number and leaf area index increased more rapidly in the air-assisted drilled rice than in the conventionally transplanted rice and this resulted in higher light interception of the canopy in the air-assisted drilled rice. Compared with the hill-seeded and conventionally transplanted rice, the air-assisted drilled rice had a lower light extinction coefficient of the canopy at the ripening stage and larger number of crown roots on the main stem with more nitrogen accumulation during the ripening period. These characteristics might contribute to the higher dry matter production in the air-assisted drilled rice.