In vitro studies on the toxicity of culture filtrates of different fungi on the growth of Fusarium oxysporum f.sp. vasinfectum

Abstract

The effects of culture filtrates of different fungi on the in vitro growth of Fusarium oxysporum f.sp. vasinfectum and the impact of these filtrates on wilt incidence were investigated on cotton seedlings cv. Barakat. The culture filtrates of the tested fungi were significantly inhibitory to the growth of Fusarium oxysporum Esp. vasinfectum. Reduction in mycelial weight of the fungus was directly correlated with concentration of the fungal filtrate. Arthrobotrys oligospora culture filtrate at different concentrations was the most inhibitory as compared to the other fungi. The toxicity was largely influenced by the type of liquid culture medium and dilution used. Rhizopus nigricans culture filtrate had significant stimulatory effects on the growth of Fusarium oxysporum f.sp. vasinfectum. The culture filtrates of the tested fungi were also reduced the wilt incidence in cotton plants with, 75% reduction obtained by Arthrobotrys oligospora culture filtrate. Spore germination of Fusarium oxysporum f.sp. vasinfectum was also affected differentially by the use of the different fungal filtrates. Culture filtrates of fungi could be used as source of biological fungicides to control wilt disease in Gezira area of the Sudan. © 2007 Asian Network for Scientific Information.