St Albans and Harpenden researchers warn about climate change impact on crops

There is a risk that severity of epidemics of some wheat disease may increase within the next 10-20 years, according to a study by international researchers led by the University of Hertfordshire, including St Albans’ Prof Bruce Fitt, professor of plant pathology.

And in Harpenden, Rothamsted Research scientists are in collaboration with an EU consortium which has developed a model to predict the shift in distribution of ragweed in northern latitudes.

A native plant of North America, contaminated crop seed is helping ragweed to spread rapidly through Europe.

Dr Jonathan Storkey, Rothamsted’s lead scientist for the study, said it was a serious weed which has highly allergenic pollen, with late flowering that would extend the current hayfever season.

The weed has already spread into Hungary and the Rhône valley in France.

Dr Storkey said the climate in the south of the UK was predicted to be suitable for ragweed populations, but its establishment and spread would depend on cultivation of crops such as maize and sunflower.

Rothamsted has urged ongoing surveillance and research on existing ragweed patches in the UK.

When a weather-based model was developed at the centre to predict how climate change might affect wheat crops, it showed that wheat flowering dates would be earlier, and the incidence of disease would increase substantially.

Prof Fitt said: “We know that the weather plays a big part in the development of disease in wheat crops [but] there is considerable debate about the impact of climate change on crop production.”

Wheat, one of the world’s most important crops for human consumption, is milled for use in bread, confectionery and other foodstuffs.

During severe epidemics, wheat crop losses can be as much as 60 per cent.

Research based on climate change models are predicting warmer, wetter winters in the UK, which will result in a greater incidence of a type of blight on wheat crops by the middle of this century.