The National Crop Loss Assessment Network (NCLAN) is a group of organizations cooperating in research to assess the short- and long-term economic impact of air pollution on crop production. The primary objectives are (1) to define relationships between yield of major agricultural crops and doses of ozone, sulfur dioxide, nitrogen dioxide and mixtures of these pollutants and (2) to used these relationships to assess the economic consequences of exposure of crops to ambient levels of these pollutants throughout the United States. This is the third annual NCLAN report, covering the period from 1 February 1982 to 31 January 1983. During this period, there was increased emphasis on studies to measure ozone dose-plant response relationships. This was accomplished for winter wheat at two regional sites, and for kidney bean and grain sorghum.