The University of California, Riverside (UCR or UC Riverside), is a public research university in Riverside, California. It is one of the 10 general campuses of the University of California system. The main campus sits on 1,900 acres (769 ha) in a suburban district of Riverside with a branch campus of 20 acres (8 ha) in Palm Desert. In 1907 the predecessor to UCR was founded as the UC Citrus Experiment Station, Riverside which pioneered research in biological pest control and the use of growth regulators responsible for extending the citrus growing season in California from four to nine months. Some of the world's most important research collections on citrus diversity and entomology, as well as science fiction and photography, are located at Riverside.