Plant response to nonfiltered air vs. added ozone generated from dry air or oxygen.

Plant responses to generated O 3 added to charcoal-filtered air vs. ambient O 3 in nonfiltered air. Alfalfa was the test crop, with plants grown in open-top field chambers. Ozone was generated from dry air for four harvests, and from O 2 for one harvest in order to determine the effects of generator air type on plant responses