The year was a “mixed bag” for diseases in the 2020 wheat crop, a Washington State University researcher says.
“A lot of it is the usual things we expect, but always a few things we don’t see,” said Tim Murray, a WSU professor and extension plant pathologist.
The university’s plant pest diagnostic clinic received 303 samples and the virus testing program ran 1,169 tests, plant diagnostician Rachel Bomberger said.
Of those, 83 were wheat and pulses and the rest were other crops, Bomberger said.
“This year, I think, was a reminder that many diseases are present at low levels or, in a sense, dormant in our cropping systems and waiting to exploit an environment that allows that disease to become more problematic than ‘normal,’” Bomberger said.
Septoria leaf spot has been on Murray’s radar for the last few years.
This season, it was primarily found in the early season and only on the lower leaves of the crop.
“I’ve seen a couple of examples where it’s moved up into the canopy later in the year,” he said. “That concerns me because it can be a real problem. This is one we are watching to see what happens.”
The disease is a problem elsewhere on the West Coast, particularly in California and the Willamette Valley. It’s not widespread in Eastern Washington.
“It’s one of those things where you keep an eye on it,” Murray said.
Many of the things that came into the clinic were typical, including rhizoctonia root rot, eyespot and pythium root rot. Those are seen every year, Murray said.
Eyespot popped up in some susceptible varieties in areas where a resistant variety could have been planted, he said. Growers seeded early last fall, and then timely rains led to good conditions for the disease to develop.
Aluminum toxicity is coming in more often as farmers and researchers recognize there is a problem in some areas, he said.
The COVID-19 pandemic changed the dynamic of how the clinic works, Murray said. Without field tours, he wasn’t able to get out to field days to speak with growers and hear what was on their minds.
Farmers considering spring wheat varieties should decide based on their biggest problems, Murray said. Stripe rust is likely the biggest concern, he said.
“I always say, ‘Pick the most resistant variety that you can that performs well in your area,’” he said. “We don’t know yet what the situation is going to be for stripe rust.”
An early winter with snow cover through early next year would suppress disease pressure. If things warm up, it could be a different situation, Murray said.
“It’s really too early to say what next year’s going to look like in terms of disease risk,” he said.