The objective of this experiment is to test the hypothesis of optimal root/shoot allocation behavior in response to relative rates of supply of root (N) and shoot (light) resources.
Agropyron repens was grown hydroponically in a growth chamber, 72 plants per container. An assay was run at 7 nitrogen levels to determine the response curve. The main experiment involved 4 treatments with 4 replicates (16 containers). All plants were grown initially at the same light-N levels, and after 4 weeks treatments received increased light (shades removed) only, increased N only, both increased N and light, or no change. Plants were harvested at 2 and 4 weeks, and then (after perturbation) every three days for twelve days and at a final harvest at 20 days. Plants were dried at 60 degrees C and then separated to root and shoot and weighed. These data will allow analysis of the biomass allocation and growth response of plants to perturbation in resource levels, specifically with respect to two theoretical predictions 1) non-additive growth response to L+N and 2) complete switching allocation in response to single resource perturbation.