Climate change brings new threats to Vermont’s famous apple orchards | Exclusive

Vermont cultivates 150 apple varieties that get juiced into cider, plucked from pick-your-own orchards and baked into pies. Growers produce roughly 40 million pounds of the fruit every year, and only dairy and maple products outrank apples in crop value.

An apple orchard is a year-round endeavor, and farmers statewide are navigating more threats from climate change to keep this Vermont fall staple going. 

“There’s pests that are here now and things that are here now that weren’t here 25 years ago,” said Phil Murdock, one of the owners of Chapin Orchards in Essex Junction.

The story behind the stories: Sign up for Free Press Selects and hear how we do journalism, free every Sunday.

This year is Murdock’s 26th season growing apples. He said one of the more prominent threats is fire blight, a highly contagious bacterial disease affecting apple trees and other plants in the rose family. The pathogen got to Vermont via windy rain, pollinating insects and contaminated gardening tools after it was first discovered in the Hudson Valley in the 18th century.

Warmer springs have caused the disease to increase substantially over the past decade, with the bacteria thriving in warmer temperatures. 

“Fire blight can devastate an orchard,” Murdock said. “It wasn’t as prevalent as it is today, and it tends to be really prolific in the springtime when you have temperatures up in the 70s and 80s.”

Fire blight causes apple blossoms to wilt black and brown and curls twigs into a distinct crook shape, as if scorched. The disease leaves sunken cankers on tree bark, and infected apples shrivel up or mummify into a hard shell. 

It has no cure, but apple farmers can prune diseased limbs and nearby bark and foliage. In severe cases, farmers may have to uproot the whole tree and take it out of the orchard. But once that tree is gone it’s safe to plant a new one. 

Heavier rain in recent years has also helped spread fungal spores that causes apple scab. 

The fungus can overwinter in dead leaves buried under snow. During spring thaw, the first rain releases those dormant spores again. Once an apple scab hotspot emerges, the infection lets out secondary spores that continue to spread on the wind through summer. 

Apple scab manifests as green and black scabs on the apple’s skin. Late-stage infections can twist or crack open apples as they mature or cause leaves to drop prematurely.

With wetter seasons, apple farmers have been more vigilant in tracking apple scab. To combat it, they mulch and mow the ground around their trees on a near daily basis all year round. 

Kim Antonioli, co-owner of Adam’s Orchard in Williston, said she trudges through the snow with her mower to make sure any hidden spores are eradicated. 

“We make sure we mow again just before the leaves start coming in the spring,” she said. “We’ve been able to mitigate and remove apple scab before it’s become a major problem.”

Murdock and Antonioli said they use traps to track pests that might bore into their fruit, too.

The larvae of the codling moth, dubbed apple worms, burrow into apple cores. Farmers hang sticky, sweet-smelling red balls from trees before peak bloom. 

The traps mimic fresh apples, ensnaring lured larvae and other critters. Farmers get a sense of what insects are concentrated so they can use pesticides in a more targeted way. 

“We can see when they’re in the orchard in a population that’s concerning,” Antonioli said. “We would want to spray instead of just guessing that they’re out there.”

Apple farmers attend an annual meeting with the Vermont Tree Fruit Growers Association to learn the latest and most efficient ways to safeguard their orchards.

At the 130th meeting in February, attendees learned how to get the most out of a free program created by Cornell University scientists called the Network for Environment and Weather Applications. It forecasts insect and disease outbreaks based on trending weather patterns. 

Apple farmers also work with the University of Vermont Extension to get the latest updates on integrated pest management — a way for apple farmers to manage crops while relying less on pesticides. 

From the extension program, Murdock said Chapin Orchards is exploring copper as a natural fungicide to combat both fire blight and apple scab.

“That resource is hugely beneficial for us,” Antonioli said. “They do all of the legwork of making sure the products they’re recommending are safe and viable and effective.”

Max Handelman is a reporting intern for the Burlington Free Press. Write to him here at mhandelman@burlingtonfreepress.com