I pronounce it peCAHN (or peKHAN) rather referring to the tree of the pie. From West Virginia. Where I have lived in the south, near the northern most area of it's natural range, on the Piedmont of NC, there is a tremendous variation in the ways people pronounce it, including variations that denote referring to the tree or referring to the pie or another dish that includes pecan nuts in it's title.

PEE CAN, PEE CAHN, peCANN. PEE cahn.

Great, beautiful, (messy) shade trees, regardless of how one pronounces them, and regardless of particular cultivar or species. I miss many things about living 10 miles east from where I live now, but most of all, I miss the large pecan tree that shaded the house from the hot afternoon suns of summer and early fall, and provided such bounty of nuts and good work sitting out at the picnic table under the hemlock on cool November Saturdays, shelling pecans to freeze, give as gifts, raw or roasted, or sell at the farmers market.

But favorite pie is still probably Apple. Love the simplicity. Make the crust, peel and slice the apples directly into the bottom shell. Add spices and a little butter, a little flour or cornstarch, no measuring needed, just eye-ball it and factor in how tart the apples tasted raw...