PARMA, Idaho — Christian Cumagun taps his experience in tropical and temperate climates to help farmers diagnose and treat the diseases that infect their crops.

“Having been to different places has given me a broader perspective,” said Cumagun, a postdoctoral researcher at the University of Idaho Parma Research and Extension Center. He was a longtime professor at the University of the Philippines Los Banos.

Experience in localities ranging from the Philippines to Japan and Germany “has, in a way, given me some different ways of thinking, and of solving problems.”

Studying leaf spot

One of the diseases he is studying is Cercospora leaf spot, a major fungus that afflicts sugar beets. An industry-funded study in its second year found that irrigating extra — particularly when the water is applied from overhead — increases the occurrence of the disease.

Early infection can reduce yields substantially whereas mature plants can be more resistant.

“It is crucial to control and manage the disease at the right time,” Cumagun said.

Fungicide investigation

Another industry-funded study looked at seven fungicides used to control white mold in pinto beans. Preliminary results show two are most effective on the soil-borne fungus — which likes high humidity — including one commonly used in Idaho.

The study addresses treatment rather than preventive measures such as using certified seed, optimizing plant spacing and siting rows to make best use of wind direction to benefit the large-canopied bean plants, Cumagun said.

“A good practice in preventing disease is to start with a clean seed, to plant good, clean seeds,” he said. He has worked on seed-related projects since starting at UI Parma in June 2021.

Virus on corn

Studying different corn varieties, Cumagun and colleagues detected High Plains virus on the seed’s embryo, endosperm and coat. They used a special test called Polymerase Chain Reaction to help determine the seed part where the virus is most concentrated.

“Preliminary studies show the virus was most concentrated on the seed coat,” he said. If that proves true, “knowing that could somehow support that prevailing theory that the virus is carried by the seed at a very low transmission rate.”

The virus overwinters in post-harvest fields and is transmitted by the wheat curl mite, often from wheat to corn.

It is not present in corn production in the Philippines, where farming has no offseason.

“Even in a dry climate like Idaho, you can get these diseases,” he said.

Pinto beans afflicted

During last year’s early summer heatwave, Pythium aphanidermatum, a new species to the region, was found in pinto bean samples from southwest and south-central Idaho and in bell pepper samples from eastern Oregon.

“This species can tolerate heat better than the other species,” Cumugun said.

Temperature and host type have differential effects on disease severity caused by Pythium species, the study concluded.

Cumagun and James Woodhall, UI plant pathologist in Parma, work on the studies and on diagnostics, analyzing plant samples with help from National Plant Diagnostic Network funding.

“This is a different kind of post-doc,” Cumagun said, as it does not focus on one project. He has enjoyed working with growers directly and seeing results in the field.

Arrived in 2020

He moved to the U.S. in March 2020 for family reasons. He worked at two major food processors in Twin Falls, as a laborer and technician.

“That was interesting, hard work compared to the Philippines in my ivory tower,” Cumagun said.

He started teaching biology online for Brigham Young University-Idaho before moving to UI Parma.

Cumagun as a youth started following in the footsteps of his father, an artist, but always “loved looking at small things,” he said.

After he won an art contest, his father got him an amateur microscope, “and the rest is history,” he said. “That was my intro to science.”

Age: 52

Hometown: Province of Batangas, the Philippines. Lives in Nampa, Idaho

Occupation: Postdoctoral research fellow, University of Idaho Parma Research and Extension Center

Education: B.S., agriculture, 1992, M.S., plant pathology, 1998, University of the Philippines, Los Banos; Ph.D., agricultural sciences with emphasis in plant pathology, 2004, University of Hohenheim, Stuttgart, Germany.

Family: Wife, Casey, four children.

Hobbies: Collecting stamps, botanical prints. Making sketches and watercolor art.