Plant Diseases and the World’s Dependence on Rice

Abstract

A rice trade crisis occurred at the beginning of 2008, which led to soaring retail prices on markets. This price spike affected foremost the poor, as rice is the staple of roughly half the poor in the world. Such events concern plant pathologists because plant diseases are major yield-reducers. Improving crop health can significantly improve yield, as well as enhance the efficiency of using increasingly scarce and often non-renewable agricultural resources: water, labour, energy and land. With two examples, we illustrate how basic plant pathological research at the gene or population level, has produced responses that led to significant yield gains and improved system performance. We also note that the timeline for research to deliver such responses is about 40 years. A shortage of agricultural resources, in turn, causes unprecedented changes in rice production situations worldwide. The relationships between production situations and crop health are well documented in rice. Changes in cropping practices and systems will inevitably lead to new crop health problems, not only in terms of emerging or re-emerging diseases but also in terms of combinations of yield-reducing factors, including diseases. Thus, in addition to addressing ‘classic’ rice diseases, such as blast, bacterial blight, or tungro, phytopathological research now has to address (1) recurrent diseases that cause regular yield attrition such as rice sheath blight, and (2) disease syndromes, which are brought about by changing patterns of crop management systems. New approaches involving knowledge from the molecular and gene level to the ecosystem level can enable plant pathologists to tackle these new challenges.