Blueberries are one of North America's only native fruits. They are closely related to azaleas, rhododendrons and cranberries - another North American native.
The tiny indigo berries with a crown-shaped bottom were one of the New World's first exports back to Europe, and they are a $600-million-a-year industry today.
There are two types of blueberry plants: high bush, which can be domestically cultivated, and low bush or wild blueberries.
The advantage of being wild
David Yarborough, a professor of horticulture at the University of Maine and a blueberry specialist, explains that there are some advantages to harvesting native stands of wild blueberries.
"There are actually hundreds of different types of plants in a field. These genetically different plants have different flavors and productivity," he says. "Instead of having one or two varieties or one or two flavors in a field, what we have is a vast mixture of flavors in a field. It gives us a very unique product."
Maine is the only state that produces that product. It grows 30 percent of all North American wild blueberries, making it the largest single producer in the world. The rest are grown in various provinces of Canada.
Last year, Maine produced 36 million kilograms of wild blueberries, grossing $72 million. Yarborough says it's a competitive market.
"In a sense, we're competing against other blueberries from Canada, cultivated blueberries, and cultivated blueberries from Chili, and even places like China are beginning to expand and put a lot of blueberries in."
Blueberry growers combine tradition and technology
For centuries, Native Americans used wild blueberries in cooking, as medicine and for dyes. They learned that periodically burning the fields would yield larger harvests the following year. That practice is still used today in Maine's 25,000 hectares of blueberry fields.
"Half the blueberry plant is underground [as a] rhizome system," Yarborough explains, "[when you] burn [the bush] off, you get these new sprouts [from the rhizomes]. You don't get any production that year, but the second year after that you get a lot more production."
Unlike the cultivated fruit, which is usually sold fresh, the smaller wild blueberries are primarily processed for jams, muffins and pies. Jeff Brann, operations manager for the University of Maine's Blueberry Hill Farm, says the delicate berries require special handling at harvest.
"They sweep them off the bushes, nice and gentle. Then they go onto a conveyer system, and it doesn't bruise the fruit as much."
He explains that method produces more "Grade A" blueberries, which bring in more per kilo than Grades B or C berries or ones that can only be used for jelly or juice.
Blueberries for health
Whatever their grade for the processor, blueberries - wild and cultivated - get high marks for their health benefits. It's been common knowledge for years that the little indigo berries are high in vitamins C and E. But demand for the fruit skyrocketed a couple of years ago when researchers discovered that they were also high in antioxidants. These natural anti-inflammatory chemicals help combat the aging process and may help prevent cancer. Wild blueberries have the highest levels of antioxidants of any fruit.
Because Blueberry Hill Farm is an agricultural research facility, its main purpose is to discover how to grow blueberries in the most efficient and profitable way possible. But the farm is doing its part in health research as well.
Scientists at the University of Maine are conducting several blueberry studies. One focuses on the cardiovascular system and the effect blueberries have on improving circulation and reducing inflammation of the arteries. Another is looking at how the fruit might help people feel full on less food.
David Yarborough says a third study is examining how blueberries improve our eyes' ability to adapt quickly to darkness… which can be life-saving on a dark road with oncoming cars.
"If you get a bright flash of light, like with oncoming headlights, how long will it take you to be able to regenerate and see? Blueberries have been shown to improve that response. It's because, again, the whole circulatory effect. Your eyes have very small capillaries in them. So if you can improve the circulation in them, you improve the functionality and the ability to recover."
Yarborough says other researchers have been studying blueberries in relation to Alzheimer's disease and diabetes.
"[The berries] don't prevent it," he points out, "but they help slow the progression of these diseases and improve health and functionality."
He adds that farmers have been successful in publicizing that information, because the demand for blueberries has gone up.
A global berry
While wild blueberries aren't easily cultivated, countries around the world - from Germany to Italy, Uruguay to South Africa - are now growing and exporting the cultivated high bush blueberries. Several processing plants have been set up in China, and a team of agricultural scientists and horticulturists at India's Dapoli University has standardized a blueberry wine-making process.
But it's not wine or wellness that Jeff Brann likes best about blueberries. It's harvesting them, in late July and August, when you can smell a fruity sweetness in the air.
"That's when your job has benefits!," he says with a laugh. "You're right in the middle of a blueberry field with delicious blueberries all around you, so..."
He mimes popping one into his mouth, fresh from the bush.