An easy, rapid method has been needed to test the pathogenicity of strains of Ralstonia pseudosolanacearum, the cause of serious bacterial wilt on ginger (Zingiber officinale). When ginger leaves were clip-inoculated with race 4 strains, yellowing and V-shaped lesions developed on leaves, but no lesions formed after inoculation with race 1 strain or on mock-inoculated leaves. Tests of different bacterial concentrations as inoculum showed that the optimal concentration was greater than or equal to 106 cfu/ml. This simple, high-throughput leaf clipping inoculation method provides an efficient, easy method to evaluate pathogenicity of R. pseudosolanacearum race 4 on ginger. [ABSTRACT FROM AUTHOR]