Ozone costing growers millions

INCREASING OZONE concentrations could be costing UK producers over £100m per year, according to latest estimates.

Loss of yield, leaf damage and poor grain quality are all symptoms of high ozone concentrations at ground level, said Lisa Emberson from the University of York.

She estimates the annual loss for UK wheat and potatoes to be around £70 million and £14 million respectively, based on experimental work from across Europe using 1990 ozone levels.

“Research into the effects of ozone on UK crops is remarkably limited given the economic implications of the problem.

“Most research has focussed on visible injuries or reductions in yield rather than nutritional content.”

Visible crop injury was generally associated with short sharp bursts of high ozone, such as last year‘s heatwave which saw concentrations peak at levels last seen in the 1970‘s, Dr Emberson noted.

Leaf bronzing, leaf spots and reduced sugar contents in grapes have all been associated with high ozone levels, she added, pointing out the impact on salad crops as of particular concern.

Before industrialisation ozone concentrations were 10-15 parts per billion (ppb), but this has now risen to around 30ppb on average and up to 100ppb on hot sunny days, she said.

“Over the past 10 years the EU has introduced various measures to reduce ozone concentration, but background levels are still increasing.

“It‘s crucial to agricultural management to understand the combined stresses of ozone pollution and climate.

“Especially so given the projected increase in background ozone concentrations and changes in climate likely to occur in the coming decades,” she concluded.

Further work is being carried out on the effect of high ozone levels on maize, tomato, sunflower and sugar beet.