Texas, Citrus CPN
The high incidence of psorosis disease prompted the Texas citrus industry to initiate a voluntary virus-free program based on California’s “Psorosis Free Program” in 1948. The discovery of CTV in nursery trees in 1992, the prevalence of sour orange rootstock, and the presence of viroids and viruses which affect alternative rootstocks were catalysts for a mandatory virus-free budwood program. Today, Texas A & M University- Kingsville Citrus Center operates the program under the authority of the Texas Department of Agriculture (TDA). The program facilities are located at the Texas A&M Citrus Center in Weslaco, Hidalgo Co.
When the decision was made for the mandatory budwood program, a foundation block was started with selected trees of the commercially important varieties of grapefruit and sweet orange. The program is enforced now by Texas State law. Fruit characteristics of the commercial varieties in the FB are evaluated annually, and when sufficient budwood from true-to-type trees is available, the state-mandated requirements will come into force. Since there is no current expansion or replanting of commercial citrus in the Rio Grande Valley of South Texas, a growing proportion of budwood is for the homeowner market, especially in East Texas.