Characterising the agricultural mosaic for effective disease control: landscape structure and crop disease

通过喷洒化学品、种植抗病品种或任何其他方法来控制作物病害，都是在单个田地的规模上进行的。然而，成功的控制取决于区域和国家层面的疾病管理。病原体在一片土地上传播的距离和速度，实际上，它是否持续存在，持续多久，取决于易感宿主的拓扑结构，以及它与典型病原体传播规模的比较。随着易感作物在景观中移动，这些相互作用的细节在时间和空间上都发生了变化。试图了解宿主空间格局对病原体动力学的影响有着悠久的历史（van der Plank, 1948），并且仍然是一个活跃的研究领域（Cunniffe et al., 2015）。探索性工作显示了如何调整DeWoody等人（2005）的工作，将作物轮作和越冬纳入农业马赛克的空间结构元种群型模型。这个项目的起点将包括理解如何使用它来通知控制部署的策略。该框架也可以扩展，最显著的是了解田间动态、种植和收获的同步性以及疾病传播的随机性的影响。了解景观结构如何影响疾病的传播将有许多应用，不仅有助于提高对如何有效控制作物疾病的理解，而且有助于提高对病原体进化变化（例如杀菌剂抗性）的理解。

Control of crop disease, be it by spraying chemicals, by planting resistant varieties, or by any other method, is deployed at the scale of the individual field. However, successful control depends on the management of disease at regional and national scales. How far and how fast a pathogen spreads through a landscape and, indeed, whether or not it persists and for how long, depends upon the topology of susceptible host and how this compares to the typical dispersal scale of pathogens. This details of the interaction changes in both time and space as the susceptible crops are moved around the landscape. Attempting to understand the effect of spatial patterning of host on pathogen dynamics has a long history (van der Plank, 1948), and is still an active area of reseach (Cunniffe et al., 2015). Exploratory work has shown how to adapt the work of DeWoody et al. (2005) to include crop rotation and overwintering in a spatially-structured metapopulation-type model of the agricultural mosaic. A starting point for this project would involve understanding how this can be used to inform strategies for deployment of control. The framework could also be extended, most notably to understand the effects of within-field dynamics, synchronicity in planting and harvesting, and stochasticity in disease spread. Understanding how the landscape structure affects the spread of disease would have a number of applications, feeding into an improved understanding not only of how crop diseases can be controlled effectively, but also of pathogen evolutionary change (e.g. fungicide resistance).