Bio-priming seed treatment for biological control of soil borne fungi causing root rot of green bean (Phaseolus vulgaris L.).

Bio-priming seed treatment that integrates the biological and physiological aspects of disease control was used as alternative method for controlling soil borne pathogens of green been. Results indicate that Fusarium solani , Rhizoctonia solani and Fusarium oxysporum proved to be the most dominant isolated fungi from roots of green bean been plants infected with root rot disease in Noubaria province. Meanwhile, Pythium spp. , and Sclerotium rolfsii show less frequent. Pathogenicity test provided that the most aggressive fungi of bean were F. solani and R. solani followed by F. oxysporum . In vitro Trichoderma harzianum, Psedomonas florescence and Bacillus subtilis cause complete reduction of the linear growth of F. salami, R. solani, F. oxysporum ,Pythium spp. and S. rolfsii . In greenhouse trails, Bio-priming seed treatments successfully controlled green bean root rots caused by F. solani , R.solani and F. oxysporum ,as these treatments reduced root rot diseases up to 73.9 and 68.5 % at pre- and post emergence stages. Meanwhile, coated bean seeds with T. harzianum or dressed with Rizolex-T caused a moderate effect in reducing root rots diseases incidence. It could be noted that practical using of bio-priming seed treatment to control root rot soil borne plant pathogens as a substitute of chemical fungicides is possible without any risk to human, animal and the environment.