Bacterial Plant Diseases in Japan

Abstract

The bacterial spot of tomato was found causing a considerable loss in the districts devoted to production of tomato in Chosen. Its symptoms were found to be identical with the description given by E. M. DOIDGE, M. W. GARDNER, and J. B. KENDRICK, however, with a greater damage on the pedicels and peduncles. On about April when the plants are still in the seedling stage, this disease first becomes apparent, causing its greatest spread in the months of June and July, especially after rain which follows the sunny days. Greatest loss occured on the soil of relatively low water holding capacity and low in organic matter.The writer has found the causal organism to be practically same as the one described by the above mentioned investigators and B. B. HIGGINS, as Bacterium vesicatorium.The infection is effected through the stomatal openings and the injured tissues, and rarely uninjured fruits. The organism overwinters in the soil and in the infected leaves, stalks and seeds. Effective control of the disease is obtained by the seed disinfection with 1: 1000 to 1: 3000 solution of mercuric chloride, followed by spraying two or three times with 3-2-75 or 3-2-90 Bordeaux mixture prior to the appearance of the disease.