Abstract
We exmamined the radioactive cesium translocation from old leaves and stems to new shoots by using uncontaminated tea nursery stocks that were sprinkled with the contaminated first crop of processed tea extracts manufactured at the Kanagawa Agricultural Technology Center Hokuso Region Office in 2011. The radioactive cesium was detected in the new shoots and the ratio of radioactive cesium concentration (137Cs concentration/ 134Cs concentration) was 1.31. It was considered that as the ratio of radioactive cesium concentration of new shoots was almost equal in that of contaminated tea extracts (1.35), and that of old leaves (1.45), and stems (1.28) 1 day after being sprinkled, the radioactive cesium sprinkled on the old leaves and stems translocated to new shoots. On the other hand, it was clear that the radioactive cesium deposited on the surface of old leaves and stems was remarkably reduced by rain. Furthermore, we investigated the radioactive cesium distribution of branches and trunks in matured tea bushes. It was clear that the radioactive cesium existed not only in the bark and cambium of branches and trunks but also their xylem nineteen months to twenty-one months after fallout.
