My research involves biology and management of plant pathogens on forests and nursery crops.

Movement of diseases and pests in nursery trade and on plant imports can cause outbreaks resulting in the near extinction of certain host plant species. The water mold Phytophthora ramorum is responsible for the outbreak of Sudden Oak Death (SOD) in California and southern Oregon, and Sudden Larch Death in the United Kingdom. This organism is moved long distances on ornamental nursery stock and short distances in water or soil.

Rhododendrons are an important host for P. ramorum and other Phytophthora species. Research on P. ramorum and other invasive plant pathogens is done in the biocontainment laboratory at WSU-Puyallup.