1981 Volume 50 Issue 3 Pages 317-325
Relationship between organ growth and nitrogen accumulation was examined using “kuntan” (rice hull charcoal) culture. The growth rate of the fresh weight of the fruit rose markedly immediately after pollination and dropped near 30 days after pollination. Growth rate of fruit even at harvest time was about a half of maximum growth rate. It is suggested that the fruit has an ability of good enlargement throughout all growth stages.
Increase in nitrogen content and dry weight in stems and leaves ceased within 30 days after pollination, while that in the fruit did not stop even at the harvesting stage. From these results, it is considered that nitrogen absorbed from the 30th day after pollination to harvest time is mainly incorporated into the fruit, and that photosynthate is actively transported to the fruit.
Increase in fresh weight and dry weight of the fruit had no relation to nitrogen uptake. It is surmised, by considering the physiological aspects of the fruit growth, that the nitrogen uptake during the first 10 days after pollination affect the enlargement of the fruit, and that it is desirable to depress the nitrogen uptake past 35 days after pollination for the production of fruit with delicate flesh and high content of soluble solid.