Climate change increases chance of harvest failures by pests and diseases

Climate change leads to higher crop losses caused by pests and diseases. But it is impossible to predict where and how these will strike. This is why scientists of Plant Research International are working on the development of robust cultivation systems to prevent immediate crop failure at the moment that a disease strikes.

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Climate models are hardly ever taking plant pests and diseases into account. But research by Plant Research International, together with plant pathologists worldwide, shows that this is wrong.Worldwide harvests would now already be 30 to 50 per cent higher if there would be no pests or diseases. And losses will only increase by climate change because existing pests and diseases are adopting to changing conditions. At the same time, crops are suffering more from stress as result of higher temperatures or extreme weather conditions resulting in a much stronger impact of pests and diseases. This means that food security is lower than currently taken into account in climate models.

Lower greenhouse gas mitigation

The extra pressure of pests and diseases is also affecting the reduction of the effect of greenhouse gases, also called mitigation. Climate models are now assuming that in particular forests in moderate climate zones can absorb greenhouse gases. Recently it has, however, been found that the destruction of forests in British Colombia as result of pests is caused by a local climate change (higher temperatures over a number of years).
Model research shows that it cannot be predicted where and how serious pests and diseases will strike. Nevertheless, it is possible to prepare agriculture for climate changes: the cultivations systems that are to be developed must be ‘robust’, where diversity is the key point. Such a system does not depend on one method of crop protection. Farmers and growers must have at their disposal all sorts of different measures to prevent or control pests and diseases. If a new, more aggressive pest or disease would then strike, by extremes as result of climate change, the farmer can with his crop protection system restrict yield losses.

Robust crop protection

Our scientists have already for a longer time been working on such a crop protection system to make farmers and growers less dependent on chemical control. A totally new framework for the protection of crops against pests and diseases is therefore not required. The scientists, however, are expecting that other elements will be need more emphasis, depending on regional climatic effects. And new collaboration networks between plant pathologist and systems and climate researchers are required as well. The PRI scientists are taking the lead.