A five-year national research initiative may help resolve a controversy over safety protocols for leafy greens and tomatoes, U.S. researchers say. Lead researcher Robert Buchanan of the University of Maryland said the national team includes top produce safety experts from several universities, industry and government. \"The science must be solid enough to withstand domestic legal challenges and international trading disputes,\" Buchanan said in a statement. \"Producers, processors and consumers must be assured that the good practice standards apply to their region -- that what works on a big farm in California, makes sense on a couple dozen acres on the East Coast.\" Ever since 2006, when a deadly batch of spinach killed three people and sickened hundreds, U.S. farm producers, packers and others along the distribution line have argued over how best to protect consumers and assure them that leafy greens and tomatoes are safe, Buchanan said. \"Leafy greens and tomatoes remain the produce items most frequently responsible for outbreaks of foodborne illnesses, yet we still don\'t know what specific safety guidelines are justified scientifically,\" Buchanan said. \"Guidelines, standards and regulations need to be based on solid science or we\'ll end up with legal wrangling rather than safer salads.\"