The present study was conducted to biocontrol in vitro and in vivo of Fusarium
oxysporum that cause Fusarium wilt diseases for eggplant plants by using biological
control agent fungus Trichoderma harzianum. Fourteen isolates from F. oxysporum
were isolated and identified from two fields in Iraq. Pathogenicity test indicated that
all F. oxysporum isolates were pathogenic for eggplant but differed in its level of
pathogenicity. Four of the fourteen isolates from F. oxysporum were selected
depending on their highest pathogenicity for eggplant plants, F. oxysporum four
isolates F5, F6, F13 and F14 achieved at pre emergence 83.3%, 83.3%, 86.7% and
83.3% and at post emergence 90.0%, 90.0%, 83.3% and 76.7% respectively. In
vitro, the antagonistic activity evaluation of T. harzianum against F. oxysporum four
isolates revealed that T. harzianum was highly significantly inhibited F. oxysporum
four isolates growth (F5, F6, F13, F14) which recorded the inhibition percentage
87.00, 89.00, 89.00, and 96.33% respectively. Greenhouse (In vivo) results of the
biocontrol efficiency of T. harzianum against F. oxysporum showed significant
reduction in eggplant Fusarium wilt incidence compared with pathogens control
treatments. The pathogen F. oxysporum treatments with T. harzianum (TF) showed
that all the treatments (TF) achieved high germination rate for eggplant seeds
compared with control treatment, while the treatment TF13 was significantly
superior than all other treatments in number of leaflets, stem height, shoot fresh
weight, shoot dry weight, root fresh weight, root dry weight and root size which
recorded 8.67, 19.00cm, 20.33gm, 4.73gm, 12.00gm, 1.53gm, 17.67cm³
respectively.
