Young maize plants have been grown for two weeks on a perlite/sand mixture under controlled high light conditions at two suboptimal nitrogen levels. The relationships between  root dry weight (RDW) and dry weight of the total plants,  RDW and total root length (TRL), and  TRL and daily N-uptake during the two weeks were different for the two N-levels. In contrast, the relationships between  the N-concentrations in shoots (NCS) and in total plants,  shoot dry weight and leaf area, and  NCS and net assimilation rate (NAR) were similar at both N-levels. Mathematical descriptions of the six experimentally derived relationships were combined in a growth model. Varying relation  in the model allowed predictions about the effect of different shoot /root ratio (SRR) on growth. Both experimentally observed SRR-relations were nearly optimal for the respective N-levels. Therefore,the SRR established by the plants was close to the 'functional equilibrium' proposed for root and shoot growth.
|Title of host publication||Plant nutrition : physiology and applications : proceedings of the eleventh international plant nutrition colloquium, 30 July - 4 August 1989, Wageningen, The Netherlands|
|Editors||M.L. van Beusichem|
|Place of Publication||Dordrecht|
|Publication status||Published - 1990|
Findenegg, G. R. (1990). Effect of varied shoot/root ratio on growth of maize (Zea mays) under nitrogen-limited conditions: growth experiment and model calculations. In M. L. van Beusichem (Ed.), Plant nutrition : physiology and applications : proceedings of the eleventh international plant nutrition colloquium, 30 July - 4 August 1989, Wageningen, The Netherlands (pp. 21-27). Dordrecht: Kluwer.