Plant Pathology Research

Project Title:  Developing new keys to Phytophthora species to promote the nation’s agricultural biosecurity

Investigator(s):   Chuanxue Hong and Mannon Gallegly

Project Summary:

The genus Phytophthora as implicated in its name (Phyto=plant and phthora=destroyer in Greek) includes a group of destructive pathogens.  The number of described species within this genus is expanding rapidly.  We recently published a new key to identify 60 species.  Our goal is to study the remaining species including those newly described and add them to the key to reduce the risk of misidentification of high-impact species such as P. ramorum and P. kernoviae. 

Project Title:  Detection of Phytophthora ramorum in Virginia waterways and the Shenandoah National Park

Investigator(s):   Chuanxue Hong

Project Summary:

Phytophthora ramorum is a quarantine pathogen that has destroyed numerous forest trees in California and Oregon and could do the same to the forests in Virginia. The primary objective of this project is to monitor whether this pathogen was accidentally introduced to the Commonwealth and prevent it from getting established in case of accidental introduction.

Project Title:  Etiology of new/emerging nursery-crop diseases

Investigator(s):   Chuanxue Hong

Project Summary:

Understanding the cause of a problem is the first and critical step to formulate a control strategy.  The objective of this inclusive research is to make science-based disease control recommendations.

Project Title:  An energy-efficient pasteurization for decontamination of recycled irrigation water in greenhouse production

Investigator(s):   Chuanxue Hong

Project Summary:

Recycling irrigation systems are a primary source of inoculums for many destructive disease epidemics in greenhouse production. Heat treatment is one water decontamination technology that is widely used in Europe but to a much lesser degree in the United States. A major limiting factor is its energy consumption and cost. The objective of this research is to look into means that could reduce the consumption and cost without sacrificing water treatment efficacy. The ultimate goal is to make this treatment a greener technology and more cost-effective.

Project Title:  Integrated management of zoosporic pathogens and water quality for a sustainable green industry

Investigator(s): Chuanxue Hong  Gary Moorman, John Lea-Cox, David Ross, Kevin Boyle, Darrell Bosch, Jim Dease, Warren Copes, Ping Kong, Belinda Carroll, Michael Stanghellini, Boris Vinatzer, Gladis Zinati, Edward Weiss

Project Summary:

This project characterizes the diversity of Phytophthora and Pythium species in irrigation system, advances our understanding of water quality dynamics and pathogen aquatic biology including their interactions with surrounding microbes in reservoirs. This project is a partnership between seven research institutions and the green industry and has a national focus. It aims to help growers build better recycling irrigation systems, allowing them to capture and reuse of runoff water for irrigation without recycling and spreading destructive pathogens. The ultimate goal is to move ornamental production towards a more sustainable industry.

Website:

http://www.irrigation-pathogens.info

Project Title:  Oomyceticide resistance and Phytophthora disease management for the ornamental horticulture industry

Investigator(s):   Chuanxue Hong , Heather Olson, Michael Benson, Steven Jeffers, Kelly Ivors, Karl Steddom, David Norman, Margaret Mmbaga, Jean Williams-Woodward

Project Summary: 

Mefenoxam and phosphite are two most commonly-used compounds for control of Phytophthora diseases in the ornamental horticultural industry. This project examines the scope and degree of resistance to these two compounds in the green industry across the Southeastern United States and understands the mechanisms underlying the resistance development. This is a collaborative project with scientists in North Carolina State University, Clemson University, Texas A&M University, University of Georgia, University of Florida, and Tennessee State University. The project goal is to mitigate Phytophthora disease risk while slowing oomyceticide resistance development.