English abstract
Fusarium vascular wilt disease is one of the most harmful diseases that affect a broad range of plant species including zucchini (Cucurbita pepo). The objective of the research was to investigate the presence of the phytopathogenic fungus Fusarium oxysporum the causal agent of the disease in zucchini fields. Forty five isolates of F. oxysporum were isolated from four locations in province of Dyala during 2014-2015. Isolate Foq9 was the most virulent in the in vitro pathogenicity test. In vitro significant suppression efficiency were observed of the fungicides Topsin M 70 WP (Tm) and Tecto 500 SC (Tc) and two botanical extract solution extracted from Garlic (Gr) and Ginger (Gn) against the pathogen on the potato sucrose agar (PSA). In greenhouse experiments all of the agents decreased the percentage of disease incidence and severity significantly, while the tetra-inoculum (Tm+Tc+Gr+Gn) was superior which exhibited 0% disease incidence and severity compared to the negative control which was 95% and 79% respectively. Also the combined application of the botanical extracts (Gr+Gn) reduced disease incidence and severity significantly. All of the treatment increased plant growth criteria represented by dry weight of the plant compared to the control.
