Fruit growers in northern Michigan are having a tough time with all the rain this year, because that moisture helps fungus and bacteria thrive.
“We seem to get rain like every other day,” says Calvin Lutz, a farmer in Manistee County. “So the ground stays saturated.”
Precipitation this year has been extreme, but conditions like this may be more common in the future because of climate change.
The fungus that causes leaf spotting in tart cherry trees is rampant this summer, more so than Lutz has seen in 40 years of farming in Manistee County.
“I’ve never seen it quite this bad,” he says. “Go around the countryside anywhere and you can see all the trees are just turning yellow and all the leaves are falling off.”
Trees that lose too much foliage can’t ripen fruit and are less likely to survive a harsh winter.
And it’s not just tart cherries having problems. Lutz lost almost his entire strawberry crop to a fungus, something he thought he’d never see on his sandy soil, which drains water quickly. That cost him about $150,000 of revenue. And sweet cherries are being attacked by a bacterial canker that there’s no defense against.
The weather is also teaching fruit growers new lessons about diseases. Researchers were caught completely off guard by fire blight in apple trees this year.
Nikki Rothwell at the Northwest Michigan Horticultural Research Station says they thought it was too cold for the disease. She says the conditions they monitor never caused the station to recommend growers spray for the bacteria this spring.
“We thought fire blight, no problem, this year. We’re not going to see any issues,” Rothwell says.
Instead it’s the worst year she has seen in 15 years.
Rothwell says they realized fire blight can thrive when apple trees grow quickly in cool, wet weather. The bacteria can infect the tender shoots. Typically the disease would infect blossoms, something that happens in hot weather.
A wetter Michigan
As the earth has warmed, Michigan has gotten wetter. Compared to 50 years ago, the state now gets three or four more inches of precipitation every year on average.
“It’s almost the same as having an additional month of precipitation,” says Jeff Andresen, a climatologist at Michigan State University.
Andresen says what was really unusual about this spring is how frequently it rained. Typically in Michigan in springtime, it rains 11 or 12 days a month. The number of rain days was twice that in some months this year.
Andresen says most climate change models show Michigan getting even wetter in the future. But what that means for fruit growers depends on when and how that precipitation arrives. He predicts we’ll likely see more precipitation in the winter months, for instance, but it is unclear if we should expect more spring seasons with constant rainfall like 2019.
“I think the jury’s still out on that,” he says.
Back at the farm, Calvin Lutz is looking at a tart cherry tree full of half-ripened fruit. He says the tree was sprayed every week for fungal disease, but most of the leaves have turned yellow and are falling to the ground.
“Yeah, it’s a disaster,” he says.
Then he pauses, smiles and says, “Next year will be better. Farmers are always optimistic.”