Nancy Leson is the first to talk up the virtues of the produce on sale at l ocal farmers markets, but she was wowed by the tomatoes she saw at Eugene's Lane County Farmers Market. Her only regret? "I just wasn't in a position to take home a box of San Marzanos that were just unbe-LEEEV-able." I had thought San Marzanos were the same thing as the Romas I'm growing. I was half-right.