Abstract
The tillering behavior of rice plants (1 plant/pot) at the late tillering stage was investigated. Assuming plant growth in which a leaf of each tiller and a leaf of the main stem expand synchronously (synchronous growth), we made a growth curve of tiller number which we called a 'synchronous growth curve (SGC). Compared the SGC with the growth curve (tiller number) obtained from actual measurement (MGC), we analyzed the pattern of tillering cessation. The growth curve of increase in tiller number of cv. Sasanishiki (which SGC was simple sigmoid curve) and the simulated growth curve (which was drawn under the assumption that every tiller had appeared) were used for the analysis. Though the tiller number of MGC suddenly stopped increasing and the relative rate of the increase in tiller number (Rt) of MGC fell off sharply, Rt of SGC decreased gradually. We thought that the factor responsible for the phenomenon was the difference (D) in growth speed between the main stem and each tiller. In relation to tillering cessation, we examined tiller positions or the last emergence daughter tillers (LMT: the tiller which emerged last from each mother tiller) and the emergence date of LMT. We also discussed the application of the concept of Rt to the analysis of the tillering at the last tillering stage.
