Since the last report on the co-culture of Las with an Actinobacter futher attempts to culture of Candidatus Liberibacter asiaticus (Las) separate from the Actinobacter have been made with 104 extracts from infected citrus, 5 extracts from infected periwinkle, and 4 extracts from psyllids fed on infected plants. Each of the extracts tested PCR-positive for the Las. Numerous culture media have been inoculated with the extracts. Primary culture attempts have tested PCR-positive for the pathogen after several weeksÕ incubation; however, this appeared to be the original inoculum and not the result of growth. Visible growth was not observed in the primary culture attempts, or in attempted subcultures. Incubating under aerobic, microaerophilic and anaerobic conditions were tried without success. The best source of inoculum appeared to be phloem tissues scrapped from the inner bark of young shoots for symptomatic citrus plants. Inoculum prepared from homogenized psyllids, petioles or midribs frequently contained contaminating microorganisms even after surface sterilization. However, inoculum prepared from psyllid extracts appeared to contain the highest concentration of the pathogen as indicated by the intensity of PCR tests. The morphology of the bacteria were what would be expected for Las. Attempts to find the appropriate medium and culture conditions for growth of the pathogen continue. Florida scions such as Navel, Valencia, Hamlin were again graft inoculated with various Florida geographic isolates of citrus greening infected budwood. Rootstocks also were inoculated and included Swingle citrimelo, Carrizo citrange, Kuharski, Kinkoji, rough lemon, sour orange and Cleopatra mandarin. As found previously all three sweet orange scion cultivars were PCR positive for Las three months after inoculation and produced the typical yellow shoot symptom which developed into a blotchy mottle if the leaves did not abscise. Swingle and carrizo plants produced mild little chlorotic symptoms but had severe leaf curling. Cleopatra mandarin had severe chlorotic symptoms while rough lemon had symptoms that were more of a leaf spotting rather than a blotchy mottle. The same symptom was seen in mature rough lemon trees in a recent trip to India. Rough lemon continued to grow when other cultivars lost leaves and had shoot dieback. Valencia plants grafted on Kinkoji were inoculated and the scions became very chlorotic and severe leaf drop occurred. Some leaves developed a blotchy mottle however many of the shoots died. After 6 months to a year most of the plants had a dieback of the canopy and some had complete dieback of the scion to the graft union. The Kinkoji rootstocks sprouted and many died. Upon further evaluation is was discovered that the rootstock had a severe root dieback and lacked feeder roots. Comparisons were made with healthy controls. Apparently the HLB infection so severely limits the ability of the scion to translocate solutes to the rootstock that the roots are killed and results in a canopy dieback. Many of the plants were used in the culturing work described above. Davis, M. J., Mondal, S.N., Chen, H., Rogers, M. E., and Brlansky, R. H. 2008. Co-cultivation of Candidatus Liberibacter asiaticus with Actinobacter from citrus with huanglongbing. Plant Dis. 92:1547-1550.