INTRODUCTION

In the summer of 1918, at Blacksburg, Virginia, there developed a considerable amount of a soft rot of tomatoes. This occurred in experimental plots which were designated to study the control of septoria leaf blight, and the soft rot of the fruit developed into an important factor. In describing these experiments Fromme (2) states: "Practically all of the unsoundness of the fruit was caused by bacterial soft rot, a disease which is exceedingly common and often very destructive in tomato fields in Virginia." Isolations from diseased fruits made by S. A. Wingard proved a bacterium to be the causative agent. Its growth in pure culture resembled that of the group of bacteria which causes soft rots of plants but it could not be readily assigned to any of the described species of this group. There has been only casual mention of a bacterial soft rot of tomato in literature, and the distinguishing features of the organisms which might be responsible have not been as sharply defined as is desirable. It was decided, therefore, to undertake comparative studies of the organism in question together with some of the non-chromogenic soft rot forms.