Synergistic interaction of Glomus mosseae T. and Trichoderma harzianum R. in the induction of systemic resistance of Cucumis sativus L. to Alternaria alternata (Fr.) K.

Due to the various negative impacts of chemical fungicides, the reduction of its applications in agricultural production process is widely recommended. Thus, the need and application of bio-agents in disease control has increased tremendously. The current study aimed at investigating the role of both bio-agents Glomus mosseae (mycorrhizal fungi) and Trichoderma harzianum in protection of Cucumis sativus (cucumber plants) against the fungal pathogen Alternaria alternata which is an opportunistic pathogen and the causal agent of cucumber wilt disease. Results obtained from this work revealed the positive influence of using bio-agents treatments in the reduction of pathogenic effects of A. alternata. The results also showed that G. mosseae and T. harzianum combination had a positive synergistic influence in reducing the detrimental effects of A. alternata ny improving the biomass yield (e.g. fresh and dry weight of root); as well as, on disease severity on C. sativus. Bio-agents (G. mosseae and T. harzianum) increased resistance in C. sativus by raising the production of enzymes catalase and peroxidase. Conclusively, this research revealed that using a multifarious combination of bio-agents significantly (P =.05) increased the efficiency of biological control of A. alternata than using each of them exclusively. Thus, it is recommended that to get an effective result in the control of the pathogen A. alternata in crops as highlighted by the results of this work; a combination of two bio-agents should be used.