Root System Formation in Rice Plant III. Quantitative studies

Abstract

Quantitative studies on the root system formation were carried out on a rice cultivar which was intermediate in leaf number (16) on the main stem. The components of the root system studied included root number, root length, total volume and surface area, for all kinds of roots, i.e., primary, secondary and tertiary. The percentage of the root system formation was as high as 40% in the main stem and 20% in the tiller VII at about 30 days before heading. Within the next 20 days or so, active growth continued in the main stem. In the tiller VII, active growth continued slightly longer. In the main stem as well as the tiller VII, the root system formation completed just after heading. The ultimate size of the root system of the main stem was 120,580 in number, 1,085 m in length, 24cm3 in volume 3,622cm2 in surface area. In the tiller VII, the root size was 50,145 in number, 464 m in length, 11 cm3 in volume, 1,532cm2 in surface area. The total root size of a single hill estimated from these data was 1,284,640 in number, 11,764 m in length, 272cm3 in volume and 39,000cm2 in surface area. © 1988, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.