Pete Walker liked to start each morning with a drive around the fields. Of course, he could monitor his crops by scanning computer screens back in the farmhouse, but he liked to see and smell the tilled soil, sprouting tendrils, bushy trees, and ripe produce for himself. He sat back in the seat of his Jeep, sipped his coffee, and looked out at the horizon. The 23,000 acres of Walker Farms stretched before him under a pale blue, invariably cloudless California sky.