Abstract
In order to obtain some informations on the variations of the carbohydrate and nitrogen contents of potato plants by applying 0.02 % 2, 4, 5-T (sodium salt) foliage sprays. the present investigation was undertaken, using potatoes of variety "Norin No. 1" as material. The results obtained may be summarized as follows : 1. In 12 hours after treatment wilting of leaves, curling of petioles and stalks were caused. The retarded growth of tops and tubers in the sprayed plots was recovered in 10 days and thenceforth surpassed their growth in the control plots. 2. In the control plots, the sugar contents stored temporarily in the tops at rhe flowering stage decreased rapidly, as tubers developed. In the sprayed plots, however, these processes were delayed. 3. In the control plots, the nitrogen contents in the tops and the tubers were high at the early stage, then decreased gradually in the later stage. In the sprayed plots, however, they decreased rapidly towards the blooming stage and thenceforth decreasing rate became loose. 4. Judging from the results it seems that the physiological role of the tops as a temporally storing organ of the assimilates was put off and intensified by treating potato plants with the 2, 4, 5-T foliage sprays.
