dc.description.abstract | Yellow disease caused by Fusarium oxysporum is an important disease on shallot which may cause 50% yield loss. The ability to spread rapidly and to survive longer in a suitable soil condition are two main factors causing its difficult to control. Many report on potential of endophytic fungi as biological control agents has been published. The aim of this research was to study the ability of endophytic fungi to suppress the development of yellow disease. The pathogenicity test of endophytic fungi isolates to shallot seeds was carried out in the laboratory and grouped them into pathogenic (growth percentage of 0%-95%), potential pathogenic (95%-99%), and nonpathogenic (100%) isolates. The effectiveness of chosen isolates (PUP1 (70%), HAP2, AAP1, MAT7 (97%) and HAP1, AAP2, AAT, PAP4, PAT3 (100%)) was evaluated in greenhouse by dipping the germinated seeds in a suspension of each isolate and inoculating the testing plant with pathogenic F. oxysporum when it was 14 days old. The effectiveness test in greenhouse showed that all treatments of endophytic fungi had an ability to suppress the development of yellow disease, significantly different to control. The percentage of highest disease incidence was shown by MAT7 isolate (38.75%) with lowest efficacy rate (34.04%) whilst the lowest disease incidence showed by PAP4 (22.50%) and PUP1 (21.25%) isolates with the highest efficacy rate (61.70% and 63.83% respectively). | en |