Bacterial wilt of potatoes. I. Field symptoms of the disease and studies on the causal organism, Pseudomonas solanacearum variety asiaticum

Abstract

By comparison with Kew South Wales and Rhodesian strains of Pseudomonas solanacearum, and a Canadian culture of Corynebacterium sepedonicum, it has been shown that the causal organism of bacterial wilt of potatoes in Victoria is a strain of Ps. Solanacearum, identified as variety asiaticum. This disease is a serious problem in the Koo-wee-rup and Gembrook areas. Many of the local isolates have no brown pigment, while others have a moderate degree of pigmentation, though much less than that of the Kew South Wales strains studied. Detailed symptoms of the disease are given; also the morphological, cultural, physiological, and pathogenic reactions compared with those of the other strains of Ps. Solanacearum studied. A serological study of these organisms will be presented in another paper.