Resistant Citrus Cultivars News Reporter With your Southeast Regional Ag Report, I'm Trevor Williams. Citrus Industry.net is reporting that HLB-resistant citrus crops might not be far off as a new research project is aimed at combating the disease. HLB, or Citrus greening disease, is one of the most destructive diseases of citrus worldwide. First discovered in the United States in 2005, HLB continues to impact Florida citrus crops as well as crops in California and throughout the world. While there is no cure for HLB, the University of Florida's Institue of Food and Agricultural Sciences, along with other land-grant colleges Texas A&M and Washington State, is developing citrus cultivars that are resistant to the disease.