The university is headquartered in the city of Berkeley in Alameda County, on the mainland side of the Bay of San Francisco, California. Additional branches are located in Los Angeles, San Francisco, San Diego and Davis. In 1880 it was decided to add viticulture and oenology as new branches. However, since Berkeley had too poor climatic conditions for viticulture, a branch was established in the interior of the country in the city of Davis (Davis is a common abbreviation for the viticulture branch). The then professor of agriculture, Eugene Hilgard, was one of several who noted the importance of grafting in the fight against phylloxera and the link between climate and the right grape variety. Prohibition (1920-1933) severely restricted the activities. Shortly after the lifting of the prohibition, in 1935, the Department of Viticulture was revived at the University. The focus was on the analysis of grape varieties and the training of the new generation of winegrowers.