Biocontrol of Fusarium root rot in squash using mycorrhizal fungi and antagonistic microorganisms

Abstract Background The study amid to investigate the influence ofTrichoderma album,T. harzianum, T.koningii,Bacillus subtilis(EF1) andPseudomonas fluorescensagainstFusarium solani, the causal agent of root rot in squash under in vitro conditions. Field experiment was conducted to evaluate the effects of arbuscular mycorrhizal fungii.e., (Glomus intraradices,G.monosporum,G.etunicatu,AMF) andT. harzianum(TZ) as well asB. subtilis(BS) either as individual or combined treatment againstFusariumroot rot of squash in two successive seasons of study 2020 and 2021 using New Eskandrani cultivar. Results Trichoderma harzianumcaused the greatest reduction in mycelial growth ofF. solani(75.17%), followed byT. albumandT.koningii. Amongst the tested 4 cultivars (Sakata, Galaxy, New Eskandrani H1 hybird, Hollr Queen F1 hybrid) in glasshouse, Hollr Queen was the most resistant to the infection ofF. solaniwith survival rate (84.92%), whereas New Eskandrani c.v was the most susceptible. Results of filed experiments proved that the combined inoculation of AMF + TZ + BS, AMF + BS, AMF + TZ, TZ + BS resulted in significant elevation of total chlorophyll, carotenoids, free phenolic compounds, free amino acids, total protein as well as the antioxidative enzyme activities (i.e.Superoxide dismutase, Peroxidase and Polyphenol-oxidase) and contents of macro and micro elements. Results further showed that the combined treatments caused a significant decrease in disease severity in both seasons with subsequent significant increase of plant growth parameters as well as total fruit yield/plant and total fruit yield/feddan. Conclusion It could be concluded that the combined inoculations of the tested bioagents proved to have potentials in control ofFusariumroot rot but large scale field experiments should be conducted before any ultimate conclusion or recommendation was drawn.