Fig. 5. Effect of ozone exposure of the shoot on (A) below-ground biomass productivity of cotton (circles) and nutsedge (squares) grown alone and on the combined biomass of one plant of each species grown in direct competition (solid triangles), and (B) on the reproductive effort of nutsedge grown alone (1:0; open squares) or averaged over all population ratios (All:1; solid squares), expressed as the number of reproductive structures per plant. Mean separation as in Fig. 1, and indicates P 0.10.