ABSTRACT
Mango (Mangifera indica L.) trees are very important trees in the world. Bacterial canker of mango trees caused by Xanthomonas campestris (Van Hall) has become a serious problem in many parts of the world. Eight isolates from X. campestris were isolated from different infected parts of mango trees with canker disease symptoms collected from different localities of Egypt. Pathogenic reaction and identification tests of eight bacterial isolates revealed that, the isolates 4, 6 and 8 identified as Xanthomonas campestris and also were indicated as the causal of canker disease. The results indicated that wounding mango transplants encourage the bacterial canker infection caused by Xanthomonas campestris. The control results of mango canker disease showed that Starner and Ofloxine were the best effective in reducing the growth of X. campestris. Also Pseudomonas putida (PT-13) isolate was the better antagonistic bacterium in reducing the growth of the tested X. campestris. Treating mango transplants with Starner bactericide, Ofloxine as antibiotic and P. putida as bio-agent as well as their combination treatments before inoculation with X. campestris (Xm4) reduced the disease and increased the activities of peroxidase (PO) and polyphenoloxidase (PPO) especially in treated plants.