Experiment was conducted to determine dose-response relationship of pinto bean and alfalfa plants to SO2 with CSTR system. Results indicated that at gi- ven concentration and periods of exposure, these species appeared to have similar suscetibility to SO2. Visible injury was produced at 0.50ppm of SO2 for 4 hours. Alfalfa showed 50% leaf necrosis at exposure 2 ppm for 4 hours. 50% leaf necrosis occured on pinto bean at 1.0 ppm for 8 hours, and developed 100% leaf necrisis at 2.0 ppm for 12 hours.The shapes ...