Founded on a legacy that began with the 1933 discovery of the viral nature of citrus psorosis at UC Riverside, the Citrus Clonal Protection Program (CCPP) has evolved through decades of citrus variety improvement and protection.
Today, CCPP is a cooperative program led by UC Riverside in partnership with UC Agriculture and Natural Resources (UC ANR), the California Department of Food and Agriculture (CDFA), USDA-APHIS, the California citrus nurseries (CCNB) , and the California citrus growers (CRB). Since 2009, CCPP has been a part of the National Clean Plant Network (NCPN) for specialty crops.