Box 5.

Pandemics of plant diseases and food security

The impact of plant disease epidemics on food security (Strange and Scott 2005) constitutes a field of research of its own, where chronic disease vs. acute disease epidemics may be distinguished (Savary et al. 2011). The latter may be caused by pandemics of plant diseases, which may affect both non-cultivated and cultivated plants (Zadoks and Schein 1979). Much debate exists as to the causes of famines in relation to plant disease (Zadoks 2008). While in many cases, deficient physical infrastructure -- roads, storage systems (hampering physical access to food) combined with the affordability of food (economic access), and the policies leading to these deficiencies, are considered the ultimate causes, plant diseases have been documented as the proximate causes of famine in several instances. The relations between plant disease pandemics and food security have especially been discussed in the case of the Potato Late Blight and the Famine of Ireland in the 19th century (Bourke 1964; Fraser 2003). The Bengal Famine of the mid-20th century was associated with the brown spot disease, a chronic disease of rice (Padmanabhan 1973).