title: Composting is an effective treatment option for sanitization of Phytophthora ramorum-infected plant material.
abstract: OBJECTIVE
  To determine the effects of heat and composting treatments on the viability of the plant pathogen Phytophthora ramorum grown on both artificial and various natural substrates.
  
  
  RESULTS
  Phytophthora ramorum was grown on V8 agar, inoculated on bay laurel leaves (Umbellularia californica) and on woody tissues of coast live oak (Quercus agrifolia). Effects on growth, viability and survival were measured as a result of treatment in ovens and compost piles. Direct plating onto PARP medium and pear-baiting techniques were used to determine post-treatment viability. No P. ramorum was recovered at the end of the composting process, regardless of the isolation technique used. By using a PCR assay designed to detect the DNA of P. ramorum, we were able to conclude the pathogen was absent from mature compost and not merely suppressed or dormant.
  
  
  CONCLUSIONS
  Some heat and composting treatments eliminate P. ramorum to lower than detectable levels on all substrates tested.
  
  
  CONCLUSIONS
  Composting is an effective treatment option for sanitization of P. ramorum-infected plant material. Assaying for pathogen viability in compost requires a direct test capable of differentiating between pathogen suppression and pathogen elimination.
authors.affiliation: Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3110, USA.
authors.forename: S
authors.initials: S
authors.lastname: Swain
authors.forename: T
authors.initials: T
authors.lastname: Harnik
authors.forename: M
authors.initials: M
authors.lastname: Mejia-Chang
authors.forename: K
authors.initials: K
authors.lastname: Hayden
authors.forename: W
authors.initials: W
authors.lastname: Bakx
authors.forename: J
authors.initials: J
authors.lastname: Creque
authors.forename: M
authors.initials: M
authors.lastname: Garbelotto
mesh_terms: D010572:Pest Control, Biological; D010838:Phytophthora / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology*; D012987:Soil / Q000469:parasitology; D012988:Soil Microbiology
chemical_list: D012987:Soil