Zinc requirements of rice at elevated CO2

The current atmospheric CO2 partial pressure of 36 Pa is expected to nearly double by the end of the 21st Century.Increases of this magnitude are likely to profoundly change the biochemistry, growth and morphology of plants, particularly C3 species.The research in this thesis focuses on the micronutrient Zinc (Zn), because this element is associated with a number of macromolecules which play key roles in plant growth and development, particularly on the shoot apex.The main objective of the work was to study the influence of elevated CO2 Zn nutrition of rice in the vegetative phase.A second objective was to investigate whether high CO2 reduced Zn concentrations in grain of cv. Jarrah and a Japanese cultivar, Akitakomachi, grown in either controlled environments, or in the field in a FACE (Free Air CO2 Enrichment) experiment. The greater Zn use efficiency of cvv. IR8 and Jarrah at elevated CO2, and the fact that high CO2 completely overcame chronic Zn deficiency at low Zn supplies, indicates that it may be possible , under future CO2 scenarios, to produce rice in areas where low soil Zn availability currently limits yield