Effects of sulphur dioxide and nitrogen dioxide on shoot and root growth of Kennebec and Russet Burbank potato plants

Abstract

The effects of sulphur dioxide (SO2) and nitrogen dioxide (NO2), singly and in combination, on the shoot and root growth of two potato cultivars sensitive to these pollutant gases were determined using rooted cuttings in controlled conditions. Plants were exposed to 0.11 ppm SO2 and/or 0.11 ppm NO2 for 24 hours a day for 7 or 14 days. Kennebec plants had significantly lower root fresh and dry weights after 7 days in the mixture treatments and lower root fresh weight in the NO2 treatment. Russet Burbank plants were more sensitive to SO2 and NO2 than Kennebec. Russet Burbank plants had significantly reduced leaf area, and leaf, stem, and root fresh and dry weights after 7 and 14 days of mixture treatment, and the leaf to root dry weight ratio was higher than in control plants. The combination treatment and SO2 alone resulted in visible injury on leaves of both cultivars. Changes in tissue water concentration, decreased specific leaf area and decreased root growth suggested that SO2 and NO2 altered plant water status and interfered with partitioning of dry matter from the leaves to other plant parts.