<p>California pistachio harvest is in full swing but as nuts are shaken from the trees and collected, some growers report blanking, or shells that contain no nuts, contributing to a smaller-than-expected crop.Jeff Gibbons of Setton Pistachio of Terra Bella puts it bluntly: "It's the worst crop we've ever experienced."Gibbons, plant manager for the family-owned company that grows about 10,000 acres of pistachios and processes pistachios for itself and other growers, attributed the smaller crop to three factors."One: There wasn't enough winter chill, so the trees did not receive enough rest," he said. "Two: It was real warm during the bloom and this made pollination unviable, and three: There is the drought."Dealing with a fourth drought year, Gibbons said, Setton Pistachio suffered another year of a zero federal water allocation in areas such as Terra Bella, and that increased the purchase price for water—if any could be found. In addition, the warm winter and lack of fog meant pistachio trees didn't gain the required 800 hours of exposure to temperatures colder than 45 degrees, needed to help set the crop."The last bad crop that we had due to lack of winter chill was in 2003, and the winter chill this year was significantly worse than it was in 2003," Gibbons said.    </p>