VIEW ARTICLE

Ecology and Epidemiology

Influence of Soil Moisture on Infection of Ponderosa Pine by Verticicladiella wagenerii. Donald J. Goheen, Plant Pathologist, U.S. Department of Agriculture, Forest Service, Forest Insect and Disease Management, Portland, OR 97208; Fields W. Cobb, Jr.,(2), and George N. McKibbin(3). (2)(3)Associate Professor and former Research Associate, respectively, Department of Plant Pathology, University of California, Berkeley 94720. Phytopathology 68:913-916. Accepted for publication 8 December 1977. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-913.

To test the hypothesis that high soil moisture favors infection of ponderosa pine by Verticicladiella wagenerii, 160 1-yr-old ponderosa pine seedlings were inoculated with V. wagenerii and subjected to two relatively dry and three relatively wet soil moisture treatments in the greenhouse. When examined after 12 wk, the largest numbers of infected seedlings were observed in the wettest soil treatments with numbers decreasing significantly (P = 0.05) as soil treatments became drier (12 of 15 to 0 of 20 seedlings infected).