Relative heat sensitivities of certain Phytophthora spp. and the potential for soil solarization to disinfest nursery beds in West Coast states
| Authors: | Jennifer L. Parke, Fumiaki Funahashi, Clara Weidman, Ebba K. Peterson |
| Year: | 2017 |
| Type: | General Technical Report |
| Station: | Pacific Southwest Research Station |
| Source: | Proceedings of the sudden oak death sixth science symposium. Gen. Tech. Rep. GTR-PSW-255. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 49-50. |
Abstract
Soilborne Phytophthora spp. can be important for initiating disease through movement of inoculum with surface water to roots or splashing onto foliage. Nursery beds infested with Phytophthora spp. can contaminate container plants set on them, causing disease year after year and posing a risk of additional spread. Persistent sources of soilborne inoculum are especially problematic for quarantine pathogens such as P. ramorum. Unfortunately, infested nursery beds are challenging to disinfest because of restrictions on the use of soil fumigants and the difficulty of accessing equipment for soil steaming.
Soil solarization has been shown to be an effective strategy to kill Phytophthora spp. in the upper layer of soil in some locations. The effectiveness of solarization treatments will vary regionally, however, due to differences in day length, solar declination angle, and local climate. To predict the effect of soil solarization, lab trials were conducted under controlled conditions to determine parameters important for inoculum survival. Inoculum survival in field trials were then evaluated where these parameters were measured and a mathematical model to predict solarization efficacy was validated.