Abstract

The allocation of a hydroxamic acid (DIBOA) and biomass was evaluated in vegetative growth stages (GS) of rye. Allocation to the shoot, root/shoot ratio of allocation, and the effect of reduced pot volume on such patterns of allocation were evaluated. Higher allocation of biomass to the shoot relative to the root as the plant aged was observed. No significant differences in allocation of DIBOA were found at different plant GS. Reducing pot volume decreased final shoot biomass. The effect at an early GS was marginally non-significant, while it was highly significant at a late GS. The effect of reduced pot volume on DIBOA accumulation differed between the GS. At the early stage the DIBOA content per unit of biomass in the shoot increased significantly with reduced pot volume, whereas at the late stage it was not significantly different. The effects of reduced pot volume on the shoot were not a consequence of a significant shift in the corresponding root/shoot ratios. While the total content of DIBOA (nmol) and the total biomass (g) in the shoot varied at similar rates in the first GS evaluated, a substantially greater relative increase in biomass occurred in the last two GS.