The overall objective of this project is to develop new girdling techniques capable of stopping or limiting the movement of CLas to the roots while allowing for normal phloem transport, thereby enabling young trees to be more tolerant to HLB in the field. Two sets of 25 trees previously girdled in a spiral pattern were allowed to recover and monitored for possible secondary effects of the girdling process. After determining that the trees were in good health condition, they were all challenged with 4 grafts of HLB infected tissue. These grafts were placed in precise locations in reference to the girdled area and were of 3 different types to ensure HLB transmission. The trees are now in the greenhouse and allowed to grow prior to testing on a quarterly manner. Six months after grafting, HLB- budded tissue continues to grow in all treatments, especially after spring flush. At this time (May 8, 2015), leaf samples were taken from the uninfected tree and sent for HLB analysis. This type of analysis will be conducted every three months. Meanwhile, all trees plus controls are being monitored for HLB symptoms. Results from the budding material came back all positive, meaning that all trees had been exposed to HLB as intended. On July 2015, all trees from both treatments were sampled for HLB. In one set of trees, leaf samples were taken from both sides of the girdle to test for the potential transfer of CLas material across severed phloem cells. In the other set of trees, in which the girdle was placed in the main trunk, was also tested for HLB. In the tree with the girdle on one side branch, 23 out of 25 trees turned out HLB+. In the other treatment, 24 out of 24 trees turned out HLB positive. From the data, we conclude that genetic HLB signal is sub-cellular in nature and can be transferred between non-phloem living cells. This new finding is important in that it shows that HLB causing effector is not necessarily the entire CLas bacterium.