Forecasting the severity of plant diseases is an emerging need for farmers and companies to optimize management actions and to predict crop yields. Process-based models are viable tools for this purpose, thanks to their capability to reproduce pathogen epidemiological processes as a function of the variability of agro-environmental conditions. We formalized the key phases of the life cycle of Puccinia kuenhii (W. Krüger) EJ Butler, the causal agent of orange rust on sugarcane, into a new simulation model, called ARISE (Orange Rust Intensity Index). ARISE is composed of generic models of epidemiological processes modulated by partial components of host resistance and was parameterized according to P. kuenhii hydro-thermal requirements. After calibration and evaluation with field data, ARISE was executed on sugarcane areas in Brazil, India and Australia to assess the pathogen suitability in different environments. ARISE performed well in calibration and evaluation, where it accurately matched observations of orange rust severity. It also reproduced a large spatial and temporal variability in simulated areas, confirming that the pathogen suitability is strictly dependent on warm temperatures and high relative air humidity. Further improvements will entail coupling ARISE with a sugarcane growth model to assess yield losses, while further testing the model with field data, using input weather data at a finer resolution to develop a decision support system for sugarcane growers.

预测植物病害的严重程度是农民和公司优化管理措施和预测作物产量的新兴需求。基于过程的模型是实现这一目的的可行工具，因为它们能够根据农业环境条件的可变性再现病原体流行病学过程。我们将甘蔗橙锈病的病原体 Puccinia kuenhii (W. Krüger) EJ Butler生命周期的关键阶段形式化为一个新的模拟模型，称为 ARISE（橙锈病强度指数）。ARISE 由由宿主抵抗力的部分组成部分调节的流行病学过程的通用模型组成，并根据P. kuenhii进行参数化水热要求。在使用现场数据进行校准和评估后，在巴西、印度和澳大利亚的甘蔗区进行了 ARISE，以评估病原体在不同环境中的适用性。ARISE 在校准和评估方面表现良好，准确匹配橙锈严重程度的观察结果。它还在模拟区域再现了巨大的时空变异，证实病原体的适宜性严格依赖于温暖的温度和高相对空气湿度。进一步的改进将需要将 ARISE 与甘蔗生长模型相结合以评估产量损失，同时使用现场数据进一步测试模型，使用更精细分辨率的输入天气数据为甘蔗种植者开发决策支持系统。