From the Wall Street Journal:

FDA Quality Control
For Frozen Cherry Pies Is the Pits to Bakers
January 20, 2006; Page A9
The bakery business wants U.S. regulators to stop picking on cherry pies.
Cherry pies are the only frozen fruit pies that must meet quality standards set by the Food and Drug Administration. Other fruit pies — including apples, blueberries and peaches — are exempt.
The FDA created the rule more than 30 years ago. At least 25% of the pie by weight must contain cherries, and no more than 15% of the cherries can be blemished. No one recalls why cherries were singled out. “We likely issued the one standard because we were petitioned to,” FDA spokesman Michael Herndon says.