Sensitivity of Selected Western Conifers to Ozone. P. R. Miller, Research Plant Pathologist, Pacific Southwest Forest and Range Experiment Station, Forest Service, USDA, Riverside, CA 92507. G. J. Longbotham, Former Junior Statistician, Statewide Air Pollution Research Center, and C. R. Longbotham, Former Lecturer, Department of Statistics, University of California, Riverside 92521. Plant Dis. 67:1113-1115. Accepted for publication 18 April 1983. 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, 1983. DOI: 10.1094/PD-67-1113.

Seedlings of 11 conifer species and two hybrids were fumigated in outdoor chambers with 0.36 ppm ozone, 12 hr/day for 37 ± 7 days. Temperatures and relative humidities experienced by the 2- to 3-yr-old container-grown seedlings were similar to the natural forest environment of these species. The Pinus jeffreyi × P. coulteri hybrid and P. monticola were the most sensitive. The order of decreasing sensitivity of the others was P. ponderosa, P. jeffreyi, Abies concolor, P. coulteri, A. magnifica, P. radiata × P. attenuata, P. attenuata, Callocedrus decurrens, Pseudotsuga macrocarpa, Pinus lambertiana, and P. ponderosa var. scopulorum.