WSU pathologist takes leading role in scientific organization

PULLMAN, Wash. - Though Kiwamu Tanaka earned a PhD in agronomy and completed a post-doctoral position working in plant-microbe interactions, he didn't work exclusively as a plant pathologist until joining Washington State University as an assistant professor in 2014.

He was recently voted president-elect of the Pacific Division of the American Phytopathological Society (APS) and assumed his role immediately following the group's annual meeting earlier this spring. He will become president after the 2026 meeting.

"As a scientist, I've always wanted to make meaningful contributions to the research community," said Tanaka, an associate professor in WSU's Department of Plant Pathology. "Whether that's through my own research projects or helping others in our field, I find it very professionally fulfilling."

While attending middle school in his native Japan, Tanaka realized that he enjoyed science and was good at it, excelling in physics, chemistry, and especially biology.

His current research focuses on controlling diseases and helping the agriculture industry better feed people around the world.

"Pathology is a complex field," he said. "We have to understand the main host organism and the crop we want to protect, as well as the pathogens hurting the crops. And equally important is how they interact within their environment to drive disease. It's a dynamic and challenging triangle between hosts, pathogens, and environmental factors."

Potatoes are one of the primary crops Tanaka is working to protect. Washington state grows nearly one quarter of all potatoes in the U.S. He said he plans to spend the next decades focusing on one particular problem: potato powdery scab disease. The disease causes blemishes on the surface of potatoes and affects the plants' roots, limiting their ability to uptake nutrients.

The disease is caused by a protozoa, rather than more common pathogens like viruses, bacteria, or fungi. Because there are fewer protozoans that harm crops compared to other pathogens, there is no effective control for it. Protozoans are one-celled organisms, like amoebas and paramecium.

Tanaka has been working to better understand this growing issue for nearly a decade, and hopes to start developing applicable treatments for growers over the coming years.

The disease has spread because it wasn't thought of as a serious problem. As long as processors remove the scabs on the skin, Tanaka said, it is unlikely to affect end products like fries or chips. However, it has been detrimental to fresh-market potatoes, as consumers don't want a scabby product.

"There is no effective fungicide, so the standard field treatment isn't effective," he said. "This disease is growing and will be the main focus of our lab's research for the next few years."

A passion for tackling those kinds of big, multi-year projects is what makes Tanaka an excellent choice to lead the Pacific Division of APS, said Lindsey du Toit, chair of WSU's plant pathology department.

"Kiwamu is a talented scientist with tremendous integrity and diligence," she said. "He has done fantastic work in his time at WSU and we look forward to his continued contributions. I'm excited to see him grow as a leader with this new role."

One of Tanaka's primary goals as APS president is to increase attendance at the division conference beyond academic scientists. He hopes to work with the private industry to increase attendance in coming years.

"I want to foster more interaction between academics and industry," Tanaka said. "We share a common goal of controlling plant diseases, and we can achieve better results by working together. I'm excited for the challenge ahead."