Influence of Ozone on Growth of Two Poplar Cultivars. J. Mooi, Research Institute for Plant Protection, Wageningen, The Netherlands. Plant Dis. 64:772-773. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/PD-64-772.

Populus x euramericana cultivars Dorskamp and Zeeland were exposed to 81 µg O₃/m³ (0.041 ppm) for 12 hr/day from 5 May to 13 October 1977 in controlled, plastic fumigation chambers in a greenhouse. The fumigation induced severe premature defoliation (about 60%), slight reduction in stem dry matter production (4–12%), and no reduction in stem elongation, compared with unexposed control plants. Foliar symptoms began to appear about 10 days after the fumigation began.