The CO2 concentration in the atmosphere is rising dramatically each year. Increases are certain to influence growth of C3 plants. This thesis focuses on the growth and development of rice (Oryza sativa L. cv. Jarrah).The major questions addressed in this thesis were whether elevated atmospheric CO2 concentrations would : 1/ increase grain yield where the soil was flooded or unflooded under conditions of varying phosphorus supply; 2/ change the timing of development; 3/ alter the partitioning of dry weight and nutrients between the roots and shoots; and, 4/ influence grain quality. The mechanisms underlying growth and developmental changes at elevated CO2 were also investigated. After experimentation, it is concluded that the grain yield of rice will increase as the atmospheric CO2 concentration rises even when phosphorus supplies are low. The largest response to rising atmospheric CO2 concentrations will occur under dryland conditions but increases of up to 60 per cent are likely in flooded rice. Importantly, there is likely to be a reduction in the life cycle of rice crops as the CO2 concentration rises. This would have the advantage that more crops could be sown in one season. The quality of the rice grain produced at high CO2 concentrations will also change, with milling quality appearance likely to improve. The cooked rice will be firmer. Experiments also showed that rice grown in flooded soil at different CO2 concentrations is an excellent system for investigating the control of plant growth and development, particularly the influence of hormones. / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:ADTP/235767 |
| Date | January 1995 |
| Creators | Seneweera, Saman P., University of Western Sydney, College of Science, Technology and Environment, School of Horticulture |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
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