Investigations of Radioactive Calcium Uptake and Translocation after Branch Injection, and Painting on the Surface of Fruits of Pear Trees under Orchard Conditions PDF

Keywords

fruit, pear, calcium

Abstract

Experiments were conducted on 60 years old 'Anjou' pear trees under orchard conditions to study the absorption of 45Ca by the fruit skin during the growing season, the mobility of 45 Ca between the shoots and the fruits. When 45 Ca (Carrier Free) was injected into the branch, 20 cm below the attachment of the fruit spur, the second week of the August, 2%of the torla 45Ca moved into the fruit within 40 days in both the sun side and the shaded side of the tree. When 45Ca was injected in the branch of 'Bartlett' pear on June 25, after removing the terminal meristem about 28% of the total Ca moved out of the application zone during the three days compared with only 17.5% of the total 45Ca moved out of the application zone if the growing point was left intact. Within three days the activity of 45Ca in the fruits on branches with the growing point removed was three times higher than in fruits on branches with the growing point left intact. When 45Ca was injected in the fruit flesh or in the carpel cavity, only a negligible amount moved out of the fruit, while the 41% of the total 45Ca absorbed by the fruit from painting on the fruit surface, moved out of the fruit to the adjacent leaves and stems within 40 days.