When prevention fails. Towards more efficient strategies for plant disease eradication

Pathogen exclusion through quarantine is the most effective strategy for plant disease prevention. However, phytosanitary measures usually restrict the movement of forest and agricultural goods, which may conflict with trade interests. In fact, increased trade in commodities has been associated with more frequent biological invasions in recent decades (Hulme, 2009). In this issue of New Phytologist, Hyatt-Twynam et al. (pp. 1317–1329) compare strategies for the eradication of emerging plant disease epidemics. Using the example of citrus canker, caused by the bacterium Xanthomonas citri subsp. citri, in residential areas in Florida (USA), the authors compare three strategies judged by the estimated number of citrus trees eliminated. The classic constant radius removal turned out to be less efficient than the proposed variable radius, and risk-based strategies, which incorporate more mathematical complexity and epidemiological background knowledge.