In Japan, the fruit growers pinch not rarely in summer the vigorously growing shoots of fruit trees, intending to get flower buds on them, and it is believed that this practice brings about in the pinched shoots the carbohydrate accumulation, and the carbohydrate-nitrogen ratio becomes, consequently, high enough to differenciate flower buds, for the growing tip of shoots, which spends carbohydrates much, is removed and the elongation of shoots is checked by pinching. It is, however, doubtful

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... ther the carbohydrate accumulation is actually produced by pinching, and no investigation which studied the chemical changes taken place in the pinched shoots, has been reported. The present brief report of the investigation which is one phase of the studies on the physiological foundation of the tree responses to pruning, deals with the changes in chemical constituents of the pinched shoots of the Japanese pear trees. Material and Methods Three, circ. 20-year-old Japanese pear trees (Pyrus serotina Rehder) of the variety Imamuraaki, grown in the orchard of the Tokyo Imperial University at Komaba, Tokyo, were selected for the study. Many pairs of shoots were chosen for uniformity, and tabulated, one of each pair being pinched and the other remaining untreated as check. In the pinching treatment of this study, the soft terminal portion of shoots was removed at the point 2 or 3cm. below the tip with the nails of fingers. After several weeks the pinched and the untreated shoots were collected, immediately stripped of leaves and the fresh weights determined.