This thesis quantifies the effects of environment (e.g. temperature and photoperiod) on vegetative and reproductive development of subterranean clover (Trifolium subterraneum), including time of flowering, seed set and hardseededness. A reanalysis of published literature for sub clover cultivars grown in different latitudes across Oceania showed that flowering occurred after 44 to 271 days, or 628 to 2600 °Cd (Tb=0). An experiment then quantified the cardinal temperatures and thermal time requirements for ‘Monti’, ‘Narrikup’, ‘Antas’ and ‘Denmark’ sub clover cultivars. All had a base temperature (Tb) of 0 °C. The optimum temperature (Topt) was 16 °C for ‘Monti’ and ‘Narrikup’ but 22 °C for ‘Antas’ and ‘Denmark’. The maximum temperature (Tmax) was 36 °C for ‘Antas’ and ‘Denmark’ and 39 °C for ‘Monti’ and ‘Narrikup’. The thermal time requirement for 50% germination was ~36 °Cd A subsequent field experiment showed the minimum thermal time requirement for six sub clover cultivars to complete their annual lifecycle (V0-R11) ranged from 1269±37.0 °Cd for ‘Monti’ to 1434±125.0 °Cd (123±6.0 days) for ‘Antas’. Carmen was supervised by Prof Derrick Moot.
Carmen is currently working with the Dryland Pastures Research Group on the Hill Country Futures programme (BLNZT1701) funded by Beef + Lamb New Zealand, MBIE, Seed Force New Zealand and PGG Wrightson Seeds.