Onion productivity marks focus of plant research

PULLMAN – WSU plant pathologists have won more than $1 million in grant funding to participate in a multistate team of scientists and industry professionals to create a suite of management tools to improve the production and profitability of the U.S. onion industry.


Brenda Schroeder, an assistant professor in the WSU Department of Plant Pathology, is one of five co-principal investigators on the team directed by Howard Schwartz of Colorado State University and James VanKirk of North Carolina State University on a $2.4 million grant from the U.S. Department of Agriculture Specialty Crops Research Initiative. She also was recently awarded funding from the Western Regional Integrated Pest Management grant program.

The long-term goals of the project are to develop, fully deploy and evaluate a sustainable online information-management platform called Onion ipmPIPE – Pest Information Platform for Extension and Education – to integrate innovative diagnostic tools and optimize sound pest management decision-making in specialty crops such as onions.
Onion growers especially need diagnostics for Iris yellow spot virus, bacterial and fungal diseases, insect pests and vectors like thrips; and an integrated pest management ipmPIPE infrastructure and access to information from the team of specialists.
“My role in this project is to lead the team in the development of diagnostic tools for bacterial and fungal pathogens of onion, and to coordinate the WSU team’s activities in overall pest diagnostics,” Schroeder said. Every year, iris yellow spot virus and onion thrips, as well as numerous bacterial and fungal diseases, threaten onion crops nationwide.
Hanu Pappu, professor of plant pathology and an expert on tospoviruses in vegetables, will coordinate virus archiving in Washington and six other cooperating states and enhance virus diagnostics. A critical component of the development of the Onion ipmPIPE is the collection and distribution of data in real-time for immediate access and use by the stakeholders.
Lindsey du Toit, associate professor of plant pathology, located at the WSU Northwestern Washington Research and Extension Center at Mount Vernon, will oversee the data collection relative to fungal diseases, thrips, IYSV and bacterial diseases from onion Sentinel Plots in the Columbia Basin.
Finally, Schroeder, du Toit and Pappu will work closely with Extension Educators Timothy Waters and Carrie Wohleb to deliver the information collected by this project to onion stakeholders in the Pacific Northwest via presentations at the Pacific Northwest Vegetable Association Conference and the WSU Onion Cultivar Field Day.
Schroeder and du Toit will also be responsible for developing a DNA macroarray detection method for bacterial and fungal pathogens that can affect onions in the field and during storage.
“The proposed research is expected to provide diagnostic tools that will enable onion growers and packers to obtain accurate and rapid diagnoses of the causes of onion diseases, and detect the presence of latent infections by pathogens capable of causing onion bulb rots in storage,” Schroeder said. This will provide an “early detection and monitoring tool” that key stakeholders identified as a critical need for onions in the western states.
“Another valuable aspect of this project is that, once the DNA macroarray is functional, it can be used to develop risk assessment parameters for onion bulb rot pathogens,” du Toit said.  Du Toit will collaborate with WSU statistician, Rich Alldredge. They will use pathogen incidence data obtained using the DNA macroarray, along with disease incidence and progress data collected with Schroeder to enable stakeholders to determine which onion bulb crops are at risk for development of storage rots. This will provide a management tool not currently available to onion stakeholders.
“The Plant Pathology Department at WSU has one of the strongest and most successful vegetable pathology research and extension programs in the country today” said Pappu, chair of the department of plant pathology.  “This grant enables us to carry out a comprehensive study at the regional and national levels and to better manage the diseases affecting onion production.”