The lighting of sorting lines in California's stone fruit packinghouses, which process peaches, plums and nectarines, varies widely, according to a study by a UC Davis agricultural engineer. A survey of nine sorting lines revealed that illumination ranged from 500 lux to 4,000 lux, compared to the recommended lighting of 1,000 lux. (A lux is a unit of illumination equal to the lighting on a surface that is at all points 1 meter from a candle.) "The survey simply documents what is going on in industry," explained Michael J. Delwiche, an associate professor of agricultural engineering. "Proper lighting for these sorting lines is very important, because employees are trying to manually sort out the bad fruit from the good." Delwiche will report on the survey at 10 a.m. on Friday, Dec. 20, during a talk titled "Lighting for the Manual Sorting of Stone Fruit."