GONZALES, CALIF. -- Melanie Horwath phoned the California Tomato Board with what she assumed was a simple request. She needed promotional materials that her family's tomato packing company could display at a Salinas Valley agricultural event called Taste of the Valley. Do you have posters or recipes? she asked. We don't have that. What kind of promotion do you guys do? We don't do that kind of promotion. That's odd, Horwath thought. Her company paid thousands of dollars a month in mandatory dues to finance the board's research and marketing efforts: its legal purpose. She started digging into the board's...