Application of Some Plant Essential Oils to Control Fusarium Isolates Associated with Freshly Harvested Maize in Egypt

Maize (Zea mays L.) is a very versatile grain that serves as starting raw material for food and feed products, whereas fungal infection with Fusarium species have a negative effect on the yield and quality of the crop. Thus the aim of the current study was to isolate and identify fungi associated to maize grains collected from Cairo and Giza governorates, Egypt, and to evaluate the antifungal effect of some essential oils on the Fusarium isolates. Giza governorate showed higher percentage of infection ranging from 91.7 to 100 % compared to Cairo governorate which ranged from 33.3 to 83.3 %. Seven genera were isolated on Potato Dextrose Agar medium, and the most prevalent fungi were Aspergillus (55.6 %), followed by Alternaria (15.0 %), Penicillium (10.9 %) and Fusarium (5.7 %). On PCNB Fusarium selective medium, five genera were isolated and Fusarium was the most predominant fungi (85.4 and 74.8 %) followed by Aspergillus (7.6 and 10.9 %) from Cairo and Giza governorates respectively. Ten Fusarium species were identified including, F. avenaceum, F. moniliforme, F. semitectum, F .solani, F. oxysporum, and F. graminearum. Antifungal activity of essential oils against the Fusarium isolates showed that rocket had high antifungal activity followed by tea tree and rosemary essential oils respectively. Inhibitory Concentration at 50 % (IC50) and Minimum Inhibitory Concentration (MIC) ranged from 0.044 to 0.049 % and 0.087 to 1.00 % for rocket essential oil, and from 0.049 to 0.282 % and 0.455 to 0.616 % for rosemary essential oil, and from 0.043 to 0.170 % and 0.192 to 0.361 % for tea tree essential oil respectively. It could be concluded that essential oils can be applied as bio control agents to prevent the growth of toxigenic and non-toxigenic species of Fusarium.