http://ipraudio.interlochen.org/cherry_canker.mp3
By Bob Allen
By now it's well-known that the state's tart cherry crop was basically wiped out by unusual spring weather this year. Michigan is the top producer of tart cherries in the country.
But perhaps worse than that, freezing weather injured sweet cherry trees so badly that a bacterial disease has taken a strong hold. And it will continue to do damage for years to come.
That puts a cloud over a fresh sweet cherry market that has been a bright spot for some growers.
Canker Widespread
Bacterial canker is just about everywhere outdoors. Usually it gets into fruit trees where there's been a wound to the bark. But this spring numerous hard freezes killed fruit buds and caused tiny injuries in the flesh of the trees. And that allowed the bacteria to take hold like never before.
"I believe this year is significantly worse than anything I've seen," says Jim Nugent. "It was just tremendous pressure. Tremendous."
Nugent has been a cherry grower and researcher in Leelanau County for more than thirty years.
Many of the lower branches in his sweet cherry trees look blasted. There are dead buds, coated with a gummy amber ooze, surrounded by brown shriveled leaves.
This canker thrives in cool wet weather. And there was plenty of that this spring. And it primarily strikes sweet cherries, some varieties more than others. Tarts are more resistant.
Lasting Damage
What was unusual this year was fruit trees were stuck for weeks in their bloom phase. And that gave the canker plenty of time to kill parts of the tree that produce buds for next year.
This section of Nugent's orchard is just coming into its prime after fifteen years. And he would have expected it to yield a lot of cherries for another decade.
"And with the amount of bacterial canker infection in that block today it's never going to produce as well as it should for the rest of the life of that orchard," Nugent says.
He says if he had to choose between the two disasters this year, loss of the tart cherry crop or canker infection in sweet cherries he'd choose the crop loss. He expects to see trees weakened and dying from this infection for several more years.
Either way, this is proving to be sort of a heartbreaking spring for fruit growers.
Basic Research
"There's, you know, some really beautiful orchards taken out by this disease," Nikki Rothwell says. She directs the Horticultural Research Center in Northwest Michigan.
Rothwell is pulling together an effort to document how much damage bacterial canker is doing. And she's trying out some sprays of nutrients, such as nitrogen, in a few orchards. That may bolster tree health and help to minimize the most severe effects.
"How do you prevent a year like this," Rothwell asks. "Is there a nutrient spray? Could we prune at different times?"
Researchers at the Hort Station hope to come up with a few answers for growers for next year.
Some growers have been wondering about using an antibiotic spray such as streptomycin to kill canker. It's been allowed for use in apples in certain counties to fight a similar bacterial infection called fire blight.
But the EPA hasn't allowed its use in cherries. And some medical doctors worry that overusing antibiotics spreads resistance among bacteria.
Fresh Market Hurt
Fruit trees are a thirty year investment. And growers can't make money with dead and dying trees. For this year, the supply of Michigan sweet cherries will be way down and the price way up.
That's too bad for a grower like Gary Bardenhagen. He's shifted a fair part of his orchards away from tart cherries and more toward supplying the fresh sweet market.
Those are the little beauties that people love to pop into their mouths in the summer.
But Gary isn't sure whether he can recover the cost of hand picking what little fruit there is this year for the fresh market.
"We're going to come off a record year of last year, great profits on sweet cherries to a year where we're probably going to lose money," Bardenhagen says. "We'll weather it. Borrow a little money, perhaps, short term and get through it."
And he hopes maybe he'll have some fresh sweets ready to sell at this year's Cherry Festival.