THE GENERAL OBJECTIVE IS TO TEST WHETHER THE AMBIANT CONCENTRATION OF AIR POLLUTANTS IN IMPORTANT AGRICULTURE AREAS AFFECT THE CROP YIELD OR NOT.

THE PROPOSED RESEARCH IS PART OF A COORDINATED PROGRAMME, THE EUROPEAN OPEN-TOP CHAMBER PROJECT. THE PROPOSAL IS ONE OF A SET OF THREE INTEGRAD PROPOSALS FROM THE U K, AND IS CLOSELY LINKED THROUGH THE COMMITTEE FOR AIR POLLUTION EFFECTS RESEARCH WITH OTHER UK PROJECTS IN THE AIR POLLUTION FIELD SUPPORTED BY THE EEC.

STUDIES WITH OPEN-TOP CHAMBERS CARRIED OUT AT OUR ASCOT SITE DURING THE SUMMER PERIOD OVER THE PAST TEN YEARS HAVE CONSISTENLY SHOWN INCREASED GROWTH IN FILTERED AIR TREATMENTS, WITH EFFECTS BEING MOST MARKED DURING PERIODS OF HIGH OZONE (03) CONCENTRATIONS. LEGUMES ARE AMONG THE MOST SENSITIVE CROPS STUDIED IN THIS EXPERIMENTAL PROGRAMME, AND IT IS HIGHLY PROBABLE THAT COMPARISONS OF FILTERED AND UNFILTERED AIR TREATMENTS WILL CONTINUE TO SHOW SIGNIFICANT EFFECTS. IT IS THEREFORE PROPOSED TO EXTEND THE RANGE OF EXPERIMENTAL TREATMENTS TO INCLUDE ONE WITH PARTIALLY FILTERED AIR AND ONE WITH ADDITIONAL INPUTS OF 20 PPB O3 ONLY ON DAYS WITH CLIMATIC CONDITIONS SUITABLE FOR O3 PRODUCTION. THIS WILL PROVIDE A DOSE-RESPONSE AT CONCENTRATIONS AROUND THE CURRENT AMBIENT LEVELS, AND THUS WILL BE PARTICURARLY USEFUL IN ASSESSING THE POTENTIAL EFFECTS BOTH OF A CONTINUED INCREASE IN EMISSIONS AND O3 CONCENTRATIONS AND OF REDUCED CONCENTRATIONS PRODUCED BY THE APPLICATION OF EMISSION CONTROLS. IT IS INTENDED TO CONSTRUCT THIS EXTENDED FACILITY AT A NEW LOCATION AT HURLEY, 47 KM WEST OF LONDON.