Abstract:The aim of the present study is to evaluate the biological control aptitude of the cyanobacteria, Anabaena subcylindrica, Nostoc muscorum and Oscillatoria angusta filtrates on the growth of the isolated pathogenic fungi from the different organs of Faba bean. Three caynobacterial (Anabaena subcylindrica, Nostoc muscorum and Oscillatoria angusta) filtrates were prepared in different concentrations and their effects on the isolated pathogenic fungi from leaves, stems and roots of Faba bean were studied. The study revealed high efficiency of the three algal filtrates on the control of the isolated pathogenic fungi from the three organs of Faba bean plants. The reduction in fungal mat growth diameter was greater than in that of the fungal dry weight showing inhibited fungal spread by greater rate. The reduction in the fungal dry weight was mostly linear and significantly correlated with the algal filtrate concentrations. The Efficient Algal Filtrate Concentration (EAFC) ranged between 104 and 461% for the three algal filtrates on the studied fungi dry weight. Complete control of the isolated fungi could be achieved by of a mixture of two algal filtrates in their EAFC and that of Nostoc muscorum + Oscillatoria angusta filtrates with an EAFC 368 and 194% were the best and economic mixture.