Phenological development and hardseededness of subterranean clover (PDF 9.9 MB)
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.