The impact of tropospheric ozone pollution on trial plot winter wheat yields in Great Britain – An econometric approach

Abstract

Numerous experiments have demonstrated reductions in the yields of cereal crops due to tropospheric O 3, with losses of up to 25%. However, the only British econometric study on O 3 impacts on winter wheat yields, found that a 10% increase in AOT40 would decrease yields by only 0.23%. An attempt is made here to reconcile these observations by developing AOT40 maps for Great Britain and matching levels with a large number of standardised trial plot wheat yields from many sites over a 13-year period. Panel estimates (repeated measures on the same plots with time) show a 0.54% decrease in yields and it is hypothesised that plant breeders may have inadvertently selected for O 3 tolerance in wheat. Some support for this is provided by fumigations of cultivars of differing introduction dates. A case is made for the use of econometric as well as experimental studies in prediction of air pollution induced crop loss.