Pink Rot of Potatoes Caused by Phytophthora erythroseptica Pethyb.

During the summer of 1943 reports were received of rotted tubers occurring in fields of early potatoes in central Nebraska. An estimated 10 per cent of the tubers were found rotted in some fields on August 5. In November and December of the same year the late-producing area of western Nebraska reported the occurrence, at harvest and in storage, of tuber rots differing from those previously recorded for that area. Specimens appeared similar to those observed during the summer in central Nebraska. Isolations were made and pathogenicity tests were conducted both on tubers and growing plants to study the influence of various factors on infection and on the development of the disease. The organism was subsequently identified as Phytophthora erythroseptica. Because of the paucity of information on this disease in the United States, its confusion with other tuber rots such as leak, and the lack of information concerning the effect of environmental factors on its distribution, it was considered desirable to publish the results of the experimental tests along with a review of previously published work