Evaluation of the efficiency of some bio-control elements and plant cultivar in resisting the death and wilt disease of eggplant plants caused by the fungus Verticillium nubilum in Babylon / Iraq

Abstract

Isolation and identification results showed that different isolates were obtained from different regions of the pathogenic fungus Verticillium spp. The results showed that there was a high antagonistic ability between the pathogenic fungus V.nubilum and the elements of the biocontrol , compared to the control treatment, which amounted to 0.0%, as the treatment of Bacillus subtilis gave the highest inhibition rate against the pathogenic fungus, which amounted to 96.75%, followed by the treatment of  Trichoderma harzianum. It reached 91.07%, and Beltanol treatment gave an inhibition rate of 100%. The results of the greenhouse also showed the effect of the used biotreatments on the inhibitory effect of the pathogenic fungus Verticillium nubilum, significantly, as it provided good protection for some varieties of eggplant plants used in the experiment from disease, which led to a significant reduction in the percentage of infection severity.The treatment of integration of the biofungus T. harzianum and the bacteria B.subtilis excelled in reducing the severity of infection with the pathogenic fungus of the three selected eggplant cultivars (Barcelona, Samara, and Zumurud ), which amounted to 5.55, 8.33, and 11.11, respectively.Compared with the treatment of the pathogenic fungus V. nubilum alone, in which the infection intensity was 83.33, 91.66, and 94.44, respectively.The results of the field experiment confirmed the results of the greenhouse experiment, as the addition of  biocontrol factors represented by the fungus Trichoderma harzianum and the bacterium Bacillus subtilis had a significant antagonistic effect against the pathogenic fungus V. nubilum,  The biointegration treatment of T. harzianum and bacteria  B.subtilis excelled in reducing the infection severity of the selected cultivars (Barcelona, Samara, Zumurud ), reaching 2.77, 5.55, and 8.33, respectively, compared to the control treatment (the plant with the pathogenic fungus), which amounted to 77.77, 80.55. , 83.33 respectively ,This was positively reflected in the rate of vegetative and root growth length, fresh and dry weight of the plant and root for the canopy experiment and the field experiment. The Barcelona cultivar also gave the best results in terms of resistance to the pathogen and plant growth criteria.