The University of California, Riversie, commonly known as UCR or UC Riverside, is a public research university and one of 10 campuses of the University of California system. The main campus sits on 1,200 acres (486 ha) in a suburban district of Riverside, California, with a branch campus of 20 acres (8 ha) in Palm Desert. Founded in 1907 as the UC Citrus Experiment Station, Riverside 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 photography, are located at Riverside.