Abstract Since new varieties are released continuously in the Brazilian sugarcane agro-industry, the understanding of their growth, development and yields are necessary. In Brazil, there is a lack of studies on sugarcane variety traits for canopy development and yields, especially those employed by the sugarcane modelling community. This paper assessed the canopy development and light interception by 27 sugarcane varieties grown at two tropical sites (Sao Romao, MG, and Guadalupe, PI) under non-limiting (potential) conditions in Brazil and tested the capability of the well-known APSIM-Sugar model to distinguish these varieties. Parameters for APSIM-Sugar canopy traits (leaf size, green leaf number, tillering and stalk emergence) and the light extinction coefficient were derived for each variety from field experiments and by calibration for the plant cane cycle. Trait parameters were then validated satisfactorily against independent datasets from the same two sites (first ratoon cycle of 27 varieties) and a row spacing experiment at Sao Romao (plant and ratoon for six varieties). A validation was also done using published experiments in other five sites across Brazil (four varieties). After APSIM-Sugar parameters were calibrated and validated, long-term simulations were run for each variety at the two sites. APSIM-Sugar outputs of thermal time to reach 50% of canopy closure were employed to group the varieties in terms of canopy formation by clustering analysis. The four major clusters corresponded well with promotional information from breeding companies in Brazil about canopy formation. These findings suggest it is reasonable to hypothesise that the APSIM-Sugar parameters are plausible and are an important step for unravelling genetic × environment × management interactions to improve yields and quality in the Brazilian sugarcane agro-industry.

中文翻译：

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二十七种巴西甘蔗品种的冠层发育和遮光性状

摘要 由于巴西甘蔗农工业不断推出新品种，因此有必要了解它们的生长、发育和产量。在巴西，缺乏对冠层发育和产量的甘蔗品种特性的研究，特别是甘蔗建模社区采用的那些特性。本文评估了在巴西非限制性（潜在）条件下在两个热带地区（圣罗毛，MG 和瓜达卢佩，PI）种植的 27 个甘蔗品种的冠层发育和光拦截，并测试了著名的 APSIM-糖模型来区分这些品种。APSIM-Sugar 冠层性状参数（叶大小、绿叶数、分蘖和茎秆出苗）和每个品种的消光系数是通过田间试验和植物甘蔗周期校准得出的。然后，根据来自相同两个地点（27 个品种的第一个宿根周期）的独立数据集和在圣罗毛（6 个品种的植物和宿根）的行距试验，对性状参数进行了令人满意的验证。还使用在巴西其他五个地点（四个品种）发表的实验进行了验证。在校准和验证 APSIM-Sugar 参数后，对两个站点的每个品种进行了长期模拟。APSIM-Sugar 输出达到冠层关闭 50% 的热时间，通过聚类分析根据冠层形成对品种进行分组。四个主要集群与巴西育种公司关于树冠形成的宣传信息非常吻合。这些发现表明，可以合理地假设 APSIM-Sugar 参数是合理的，并且是解开遗传 × 环境 × 管理相互作用以提高巴西甘蔗农业工业的产量和质量的重要步骤。