2.3. Plant sanitary status
From June 2014 to September 2015, once per month, the overall plantvig our was described through a visual index ranging from 0(death plant) to 5 (plants at the optimal development status). In addition, all plants were visually monitored monthly for the occurrence of blister bark symptoms. Whenever blister bark symptoms were observed, tissue samples were collected from the bark for analysis and immediately stored in refrigerated plastic bags. The samples were subsequently processed for bacterial isolation.