The study aimed to identify some causes of eggplant root rot disease after isolation
and diagnosis in some areas of Babylon Governorate and to evaluate the efficiency
of the biological fungus Trichoderma harzianum and extract of some plants in control the pathogens of eggplant seedling death disease. The results of the field survey
conducted in the fields of eggplant plants in the province of Babylon showed the
presence of root rot in the eggplant in all areas covered by the field survey. Several
types of fungi were isolated and identified from the roots of eggplant plants infected with root rot disease. The most frequent pathogenic fungi were Fusarium
solani, Rhizoctonia solani, and Macrophomina phaseolina. The results showed that
all tested fungi isolates were pathogenic and caused a significant reduction in the
percentage of germination of cabbage and eggplant seeds. The results of the pot
experiment showed that all the treatments that included the biological factor and
aqueous Acacia extract had a significant effect in reducing the growth of pathogenic fungi, especially when the treatments were combined, as measured by the
percentage of infection and the severity of infection in the treatment of pathogenic
fungi F. solani, R. solani and M. phaseolina, Alone, the infection rate was 100.00%,
and the severity of the infection was 76.67, 70.00 and 66.67%, respectively. The
treatment of integration between the biological factor T. harzianum and the aqueous extract of Acacia achieved high superiority in reducing the infection rate, as it
ranged between 11.11-24.33% and the severity of infection 4.44-15.00%.
Keywords: Plant extracts, Eggplant, fungi, root rot, Trichoderma harzianum.