Climate change – impact on crop growth and food production, and plant pathogens

Climates are changing worldwide at rates not seen previously in geological time. This affects food production itself and the growth and reproduction of plant pathogens which reduce crop yield and quality. There is a need to develop an understanding of the implications and impacts of climate change on natural biodiversity, artificial landscapes as well as production agriculture (defined here as a generalization embracing all of the primary uses of land for agriculture, horticulture and forestry), since these form parts of an integrated continuum. Currently, 20–25% of harvested crops worldwide are lost to pre- and post-harvest diseases and climatic change is expected to increase these losses. Climatic change results in increasing variability and altered scales of temperature, rainfall and wind velocity and periodicity. These changes affect the activities and vigour of aerial and soilborne pathogens Some pathogens capable of devastating crops and harvested produce have become more active and damaging because their geographical ranges expand as a consequence of climate change. Human populations are increasing rapidly, resulting in greater demands on all natural resources which far outstrip supplies. Natural biodiversity is being damaged, frequently beyond repair and not infrequently with little or no knowledge of the characteristics of the plant genotypes being lost. Only very recently have analyses of ecosystem services begun revealing the intricate and delicate webs of unappreciated natural assets which are vital for human sustainable (used here to describe processes and actions which balance resource-use with resource-availability and conserve economic, environmental and social welfare) survival. The combination of climatic change, expanding human demands for food, resources and space and the increased activities of plant pathogens presents pathologists with immense challenges. Previously, visionary plant pathologists have contributed hugely to solving humanity’s problems. Current challenges compounded by climate change offer opportunities for the exploitation of our profession’s capacities for working with ‘one foot in the furrow (and) one hand on the bench’ with increasing relevance for society at large.