Prediction of lucerne phenological and morphological development is important for optimising the defoliation schedule and time of other management events. A challenge for any lucerne phenology module is to capture the seasonality of development processes in response to environment, management and genotype. To date, lucerne phenological modules have not been evaluated under different defoliation regimes or with genotypes of different fall dormancy (FD) classes. This research integrated data of lucerne phenological development into the Agricultural Production Systems sIMulator (APSIM) next generation (APSIM NextGen) model framework to develop and verify a phenology module. Relationships derived from the FD5 genotype, grown under a 42 day (LL) defoliation treatment were used for model development. These were further tested for two genotypes with contrasting FD (FD2 and FD10) under frequent (28 day: S) or long (84 day: H) defoliation regimes, all under irrigated conditions. Development was parameterized based on thermal time targets to reach specific phenological stages and modified by photoperiod responses. Development stage and node appearance were shown to be independent of defoliation treatment and FD class. Simulation results showed good agreement for prediction of development stages (NSE of 0.77 for days to buds visible and 0.67 for days to flowering stage) and number of main stem nodes (NSE values were ranged from 0.53 to 0.84). However, both defoliation management treatment and FD classes affected stem height. For FD5, there was good agreement for the 84 day treatment (NSE of 0.83) and the 42 day treatment (NSE of 0.66), but it was poor for the 28 day treatment (NSE of -0.08). This was probably due to reduced stem extension rates, limited by low C and N reserves in perennial organs under the frequent (28 day) defoliation regime. For FD2 and FD10, two separate sets of parameters were used to improve model prediction of height to account for their contrasting seasonal C partitioning patterns. These results show that the APSIM NextGen lucerne phenology module was able to simulate crops grown under unconstrained growing conditions. However, the reason for under estimation of stem height for the 28 day treatment needs further investigation.

苜蓿物候和形态发育的预测对于优化其他管理事件的落叶时间表和时间很重要。任何苜蓿物候模块的挑战是捕捉响应环境、管理和基因型的发育过程的季节性。迄今为止，尚未在不同的落叶制度或不同秋季休眠 (FD) 类别的基因型下评估苜蓿物候模块。该研究将苜蓿物候发育的数据整合到下一代农业生产系统模拟器（APSIM）（APSIM NextGen）模型框架中，以开发和验证物候模块。源自 FD5 基因型的关系，在 42 天 (LL) 落叶处理下生长，用于模型开发。在频繁（28 天：S）或长（84 天：H）落叶制度下，所有这些都在灌溉条件下，进一步测试了两种具有对比 FD（FD2 和 FD10）的基因型。发育基于达到特定物候阶段的热时间目标进行参数化，并通过光周期响应进行修改。发育阶段和节点外观被证明与脱叶处理和 FD 等级无关。模拟结果表明，预测发育阶段（NSE 为 0.77 天到芽可见，0.67 天到开花期）和主茎节数（NSE 值范围从 0.53 到 0.84）具有良好的一致性。然而，落叶管理处理和 FD 等级都会影响茎的高度。对于 FD5，84 天治疗（NSE 为 0.83）和 42 天治疗（NSE 为 0.66）有很好的一致性，但 28 天治疗效果不佳（NSE 为 -0.08）。这可能是由于茎伸长率降低，受频繁（28 天）落叶制度下多年生器官中碳和氮储量低的限制。对于 FD2 和 FD10，使用两组单独的参数来改进模型对高度的预测，以解释它们对比的季节性 C 分区模式。这些结果表明 APSIM NextGen 苜蓿物候模块能够模拟在不受约束的生长条件下生长的作物。然而，28 天处理的茎高估计不足的原因需要进一步调查。使用两组独立的参数来改进模型对高度的预测，以解释它们对比的季节性 C 分区模式。这些结果表明 APSIM NextGen 苜蓿物候模块能够模拟在不受约束的生长条件下生长的作物。然而，28 天处理的茎高估计不足的原因需要进一步调查。使用两组独立的参数来改进模型对高度的预测，以解释它们对比的季节性 C 分区模式。这些结果表明 APSIM NextGen 苜蓿物候模块能够模拟在不受约束的生长条件下生长的作物。然而，28 天处理的茎高估计不足的原因需要进一步调查。