Since race R2 and R3 were the most abundant races causing
rice bacterial blight disease in northern Vietnam, their inhibition by
actinomycete isolates was first tested and measured (Unpublished
data). Subsequently, the actinomycete isolates inhibiting both the 2
races of R2 and R3 were tested continuously for their inhibition to
the remaining 8 races of pathogens. Isolates that were able to
inhibit all the 10 races of Xoo were selected for futher study.