Thesis (Ph.D.) - Cairo University - Institute of African Studies and Research - Department of Natural Resources

Wilt diseases are the most important diseases of olive trees. Fusarium solani and Verticillium dahliae are the main causal organisms for wilt diseases. Bacterial bioagents such as Azotobacter , Pseudomonas and Bacillus were isolated from rhizosphere of different plants and tested to select the most effective organisms on the pathogenic fungi. The activity of Azotobacter chroococcum, Pseudomonas fluorescence and Bacillus megaterium as biofertilizers and biocontrol agents on the growth and yield of olive trees infected with Fusarium solani and Verticillium dahlia were studied in a pot experiment and after that applied at Siwa Oasis on the diseased Olive trees. Changes of count densities of total microbial affected by inoculation with Azotobacter chroococcum, Pseudomonas fluoresence and Bacillus megaterium either singly or in combination were studied. The obtained results showed that microbial growth is almost stimulated in the rhizosphere of olive trees inoculated with a mixture of the three biocontrol agents, while Fungal counts were reduced by such treatments. Inoculation with a mixture of the studied three biocontrol agents improved the growth of the tested plant and consequently increased the yield significantly . At the same time, harmful effects of Fusarium solani and Verticillium dahliae on plant reduced as a result of such inoculation treatments

Issued also as CD