VIEW ARTICLE

Artificial Inoculation of Pinus radiata with Scirrhia (Dothistroma) pini: Effect of Relative Humidity and Temperature on Incubation. A. K. Parker, Research Scientist, Department of the Environment, Pacific Forest Research Centre, Victoria, British Columbia; Phytopathology 62:1160-1164. Accepted for publication 8 January 1972. DOI: 10.1094/Phyto-62-1160.

In the temperature range 13-24 C and relative humidity range 70-100%, infection of Pinus radiata by conidia of Scirrhia pini was greater at the lower temperatures when accompanied by high humidity values. With a 768-hr incubation period containing an average of 580 hr of 100% relative humidity, 97, 65, and 0% of the pine became infected in temperature ranges 16-13, 21-16, and 24-21 C, respectively. With relative humidity values in the range 91-81%, only a few leaves on 47% of the pine were infected in the temperature range 16-13 C. The results suggest that leaf infection would be greater at even lower temperatures and longer incubation periods than those tested at high relative humidities.