Responses of hybrid poplar cuttings to chronic and acute levels of ozone
Hybrid poplar cuttings were exposed to either 0·15 ppm ozone for 6 weeks or 1 ppm ozone for 2, 4, or 8 h. The chronic ozone treatment reduced growth by 50% and caused injury to 75 of the leaves. The acute ozone treatment had no effect on growth but caused injury to 70% of the leaves 48 h after fumigation.