He would have done well to plant its lush canopy in Switzerland, where each year consumers eat over 4.4 pounds of hazelnuts per person. That's 70 times more than the average American, who snacks on less than 1 ounce of the round, aromatic nut per year.

Germany would have been a strategic move, too. There, consumers down over 2 pounds of hazelnuts, ground into meal and used as flour, giving flavor to cakes and breads.

In Italy, children butter their morning toast with Nutella, a chocolate-hazelnut spread, and in France, the symmetrical nut is often used as the core of chocolate truffles.

''Without even trying, the Europeans eat as many hazelnuts in a few weeks as we do here in a year,'' lamented McDonald, who planted his orchard three decades ago in Oregon, at the heart of America's hazelnut belt.

Oregon's hazelnuts are considered among the best in the world. But having exhausted their export possibilities, growers are turning their attention to their largest untapped market - their back yard.

Selling Americans on hazelnuts is bound to be an uphill battle, say industry watchers.

''Americans have a very long history with peanuts,'' said J. Frank McGill, the University of Georgia's distinguished professor of agronomy.

Compared to almost all other nuts and especially the peanut, the hazelnut has done dismally in the United States. In 1965, Americans consumed slightly less than 1 ounce of hazelnuts per person - a tiny percentage of the 5.4 pounds of peanuts eaten per capita in the form of raw nuts, candy bars, snacks and peanut butter. By 2003 - the most recent year for which figures are available - peanut consumption had boomed to over 6 pounds per person, while hazelnut consumption hadn't budged.

''We drink European wine, we drive European cars, we go there on vacation - why can't we eat their nuts?'' said McDonald.

Those in the business of marketing the nut point out that Americans do have a soft spot for hazelnut-flavored coffee - which is popular in America, not Europe, where traditional espresso still rules.

''The No. 2 coffee flavoring in America is hazelnut, right behind vanilla,'' said Vicki Nesper, marketing director of the Jersey City, N.J.-based Hazelnut Council.

The irony is that the hazelnut additive in coffees is not made from real hazelnuts.

''It's artificial,'' said Nesper. ''But we want to share the knowledge with Americans that if they like it in their coffee, then they might like real hazelnuts in other products, as well.''

Changing American tastes is only half the battle, however.

On a recent spring afternoon, McDonald stepped into his flowering orchard near the banks of the Willamette River and walked toward his beloved trees, their branches flooded with green leaves. But a closer look revealed branches that have been cut off.

''It's like finding out you have AIDS. Or cancer,'' said McDonald, recalling the afternoon of Aug. 17, 1989, when he discovered that the Eastern filbert blight had invaded his trees. ''I'm lucky I didn't lose the whole orchard,'' he said. For generations, Oregon producers called hazelnuts ''filberts,'' but they changed the name to boost marketing outside Oregon.

In the past decade, Oregon has lost more than 1,600 acres to the blight - California's almond acreage grew by nearly 132,000 acres during that period.

The blight exacerbated an already well-known supply-and-demand problem. Unlike other crops, hazelnuts bear fruit in a two-year cycle - a high yield year is normally followed by a low yield.

Cereal, chocolate and bread manufacturers that might otherwise have taken an interest in Oregon's hazelnut have been scared off, worried that if they created a hazelnut product the demand would quickly outstrip the available crop.

A decade ago, the Kellogg Co., the nation's top cereal maker, ran into that problem soon after they began testing a cereal built around Oregon hazelnuts.

''They went as far as making the box,'' said Polly Owen, manager of the Oregon Hazelnut Marketing Board. ''The only reason the line didn't continue is not because consumers didn't like it - but because they couldn't be assured of a consistent supply.''

Things are changing for the better.

One reason industry watchers are hopeful is because of a joint marketing agreement with Turkey, the world's No. 1 hazelnut producer. In an effort to enter the American market, Turkish growers joined hands with their U.S. competitors.

That is crucial for growers here, because Turkey can pick up the slack in years when Oregon's crop is at its low point, resolving the supply problem. While the blight is never far from farmers' minds - McDonald said he spent $5,000 this season pruning his trees for disease - the blight-resistant strains, including some from Turkey, are taking root.

Most encouraging of all is the boom in sales of European hazelnut products in America.

In 2002, U.S. sales of Swiss chocolate maker Lindt grew 50 percent over the previous year, according to Packaged Facts, a market research firm based in New York. Sales of the chocolate - much of which is sprinkled with hazelnuts - grew another 26 percent to $35.9 million in 2003, the last year for which data is available.

''The American palate is changing,'' said Don Stohrer, a manager for Ferrero USA Inc., the American arm of the Italian candymaker that created Nutella.