Coefficients that describe phenological development of subterranean (sub) clover (Trifolium subterraneaum L.) were derived from field and controlled environment experiments. These were combined with national scale historical climate data to estimate when key stages in the life cycle occur at different locations in New Zealand. Based on a 20 mm accumulated rainfall threshold in autumn, sub clover germination and emergence in eastern regions of the South and North Islands occurred between 10th and 24th March and later (~ 31st March) in the cooler southern areas of the South Island, after 36 ± 6.0°Cd and 115 ± 9.0°Cd, respectively. During this time the absolute photoperiod decreases from 13.7 h to 11.6 h (at latitude −34.3950) and from 14.4 h to 11.1 h (at latitude-47.2590). In spring, flowering was estimated to commence in August in North Island locations but from September onwards in South Island locations. The group of cultivars classified as ‘Late’ flowering by plant breeders were estimated to flower in the North Island starting by mid-August compared with mid-September to mid-October in southern (cooler) regions. The safe grazing period was estimated as 25% longer for ‘Late’ cultivars than the ‘Early’ cultivars. The quantification of these key phenophases can be extrapolated to different regions to enhance strategic management of weed control, grazing times and closing dates for seed set. This should enable increased species persistence of sub clover in pasture swards.

描述地下（亚）三叶草（Trifolium subterraneaum ）物候发育的系数L.) 来自现场和受控环境实验。这些与国家尺度的历史气候数据相结合，以估计生命周期的关键阶段何时发生在新西兰的不同地点。根据秋季 20 毫米的累积降雨阈值，南岛和北岛东部地区的亚三叶草发芽和出苗发生在 3 月 10 日至 24 日之间，随后（~3 月 31 日）在南岛较凉爽的南部地区，36 年后分别为 ± 6.0°Cd 和 115 ± 9.0°Cd。在此期间，绝对光周期从 13.7 小时减少到 11.6 小时（纬度 -34.3950）和从 14.4 小时减少到 11.1 小时（纬度 47.2590）。在春季，估计北岛地区的开花时间是 8 月，但南岛地区的开花时间是从 9 月开始。据估计，被植物育种者归类为“晚”开花的品种组从 8 月中旬开始在北岛开花，而南部（较冷）地区则在 9 月中旬至 10 月中旬开花。'晚期'品种的安全放牧期估计比'早期'品种长25%。这些关键物候期的量化可以外推到不同地区，以加强对杂草控制、放牧时间和结种日期的战略管理。这应该能够增加草场中亚三叶草的物种持久性。这些关键物候期的量化可以外推到不同地区，以加强对杂草控制、放牧时间和结种日期的战略管理。这应该能够增加草场中亚三叶草的物种持久性。这些关键物候期的量化可以外推到不同地区，以加强对杂草控制、放牧时间和结种日期的战略管理。这应该能够增加草场中亚三叶草的物种持久性。