Antifungal Effects of Extracts of the Cassava Organ on Fusarium oxysporum f. sp. cubense in Banana

Banana Fusarium wilt disease is caused by Fusarium oxysporum f.sp.cubense (FOC)race 4 and reported to be the most limiting factor in banana production worldwide.The antifungal effects of extracts of cassava organ on FOC population were investigated by growth rate method in this study. The above-ground and underground parts of the cassava organ during the stage of root formation were extracted by ethanol and water respectively. The results showed that the extracts had inhibition to the banana Fusarium oxysporum f. sp. cubense either by ethanol or by water. The antifungal effect of the underground organ was stronger than that of the aboveground. The antifungal effect of the 50 mg/L organ extracts were strongest in the 25 mg/L extracts and water, while the effect of the 25 mg/L and 100 mg/L extracts had no significance, therefore, the effect of 50~100 mg/L of the organ extracts were best. The inhibition rate at 24 h incubation time was highest, and had significantly diffidence in the 72 h, 96 h and 120 h.