Assessing Ground-Level Ozone (O ) Impacts to Crops in Parts of Asia and Southern Africa

Many of the studies that have identied O3 effects similar to those described above have been made using controlled fumigation techniques in order to dene exposure-response relationships. A common experimental tool for such studies has been open top chambers (OTCs) (e.g., Heagle et al., 1979), which allow controlled O3 fumigations under near-eld conditions.