When pistachio hulls split before the nuts are harvested, insects and fungi can get inside, damaging the nut, costing farmers money and contaminating the nuts. About 4% of the overall crop experiences hull split, but some cultivars can split as much as 40% under certain conditions. Now, for the first time, scientists at the University of California, Davis, are seeking solutions for California's $2-billion-a-year pistachio industry.