Fastidious pathogens, bacteria that only grow in specific conditions, cause huge agricultural losses and cost farmers billions of dollars annually. Candidatus Liberibacter spp. are fastidious pathogens that cause the potato zebra chip and Citrus greening diseases. Complicating matters, these pathogens are will not grow in laboratory conditions, making it difficult to understand them. To support citrus growers and help other producers manage diseases, Texas A&M AgriLife Research & Extension Center researchers are testing a method of screening for disease resistance genes and chemicals that can combat the pathogens causing citrus greening and potato zebra chip diseases. The research will be translated into disease management strategies that help growers and prevent billions of dollars in annual losses.