The rise in atmospheric CO2 partial pressures that is predicted for the 21st Century is likely to increase productivity and alter nutrient of C3 crop plants. Consequently, physiological data on plant growth and nutrition at elevated CO2 are required, because these data underpin simulation models, which are needed for management of crops under the CO2 scenario for the mid to late 21st Century.In particular, information is required about management of nitrogen(N) fertilisation because this mineral nutrient plays a central role in the growh of many crops. Rice was chosen as a model plant because of its widespread consumption throughout the world and its responsiveness to CO2 and N fertilisation. There were three major hypotheses: first, that early exposure of rice plants to high CO2 is required to achieve the maximum growth and tillering response; secondly, that early increases in growth and tillering at high CO2 are associated with the phytohormone, ethylene; and thirdly, that growth at elevated CO2 decreases leaf N concentrations required to support maximum dry mass production and photosynthetic rates (critical concentrations).Several tests and experiments were conducted and results noted. It is likely that grain yield will be greater as the atmospheric CO2 partial pressure rises even when N supplies are low, providing that high CO2 does not cause accelerated tiller abortion at low N. / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:ADTP/216310 |
| Date | January 2000 |
| Creators | Aben, Silvestre K., University of Western Sydney, Hawkesbury, Faculty of Science and Technology, Centre for Horticulture and Plant Sciences |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Source | THESIS_FST_HPS_Aben_S.xml |
Page generated in 0.0013 seconds