Abstract
This experiment was carried out in pot soil culture, using 15 indica varieties to determine the Varietal differences in nitrogen response at Peradeniya Gentral Agricultural Station, Department of, Agriculture, Ceylon during the 1962 to 1963. Results obtained are summarized as follows:
1. Varietal differences in shoot elongation were obtained remarkably. When the nitrogen were applied, the varieties such as V. P., Heenati 310 and H-4 were promoted shoot elongation, on the contrary, the varieties such as V. I., Remadja, M. S. g-18, H-501 and Mawi B-11 were inhibited shoot eelongation.
2. There were considerable differences among the varieties in the rate of dry-weight-increase during the 5 weeks to 6 weeks after sowing. The varieties in which shown higher the rate of dry-weight-increase, were decreased in that with the application of nitrogen, most of these varieties were not adapted for heavy manuring. On the other hand, the varieties in which shown moderate the rate of dry-weight-increase, were increased in that with application of nitrogen. These varieties such as H-4, SR26B and Pokkali were adapted for heavy manuring.
3. The varieties more suitable for heavy manuring were higher the ratio of dry weight of seedling per shoot length.
4. Contents of starch in leaf sheath of rice seedlings were varied with age of seedlings and levels of nitrogen, however, the varieties more suitable for heavy manuring were higher the starch contents in leaf sheath than the others.
5. It is clear that the rate of dry-weight-increase in rice seedlings were closely related to the content of starch in leaf sheath.
