Flowering time of cultivars of subterranean clover in New South Wales
The period from sowing to flowering was determined for 8 subterranean clover cultivars sown in late March, late April and late May at 9 environmentally distinct locations in New South Wales. The length of the period to flowering depended on cultivar (ranging from a mean of 1 12 days for Northam to 15 1 days for Larisa) and site (from a mean of 1 18 days at Grafton to 145 days at Canberra). There was a greater range in the period from sowing to flowering between cultivars at earlier flowering sites compared with late flowering sites. The period from sowing to flowering decreased with later sowings so that clovers sown late (May) flowered on average less than 14 days after those sown early (March). A relationship was developed between temperature and latitude and the period to flowering for each sowing date and cultivar. This relationship accounted for 95% ofthe variation in flowering time observed in this study and was used to predict with acceptable accuracy the flowering time of subterranean clover cultivars in a study undertaken in Western Australia in 1972 and 1973. We believe the relationship could be useful in predicting flowering time in subterranean clovers.