Fig. 7. Relationship between rate of change in potentially fertile tiller number and estimated ratio of realized/potential leaf area growth for data calculated in each of the three replications at a density of two (circles), four (upward pointing triangles), eight (squares) and 16 (downward pointing triangles) plants m^–2. Realized leaf area was estimated from estimated light interception, using the extinction coefficient, radiation use efficiency and plant leaf area ratio, as reported by Lafarge and Hammer (2002). Otherwise data were calculated as for Fig. 6. The dotted line shows the linear regression of the reference response fitted in Fig. 6.