The Response of Radish to Nitrogen Dioxide, Sulfur Dioxide, and Ozone, Alone and in Combination

Abstract

AbstractEffects on radish (Raphanus sativus L.) cv. ‘Cherry Belle’ of nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) alone and in combination at 0.2 or 0.4 ppm of each pollutant were studied. There was no difference in foliage or root weight of radish between exposure durations of 3 or 6 hours, and no significant interaction of hours with air pollutant and concentration. Ozone reduced root dry weight more at 0.4 ppm than at 0.2 ppm. Sulfur dioxide depressed the root/shoot ratio at both 0.2 and 0.4 ppm; however, when NO2 and SO2 were both present there was synergistic depression of the root/shoot ratio at 0.4 ppm. The average O3‐induced reduction in root weight of radish (1.75 g fresh and 101 mg dry, per plant) was additive in the presence of NO2 and SO2. The weight of the root was reduced even though the foliage was the direct receptor of the pollutant stress.