Internode elongation under different rising water conditions in African floating rice (Oryza glaberrima Steud.)

The african and Asian floating rices were grown under different rising water conditions, and internode elongation ability with increasing water depth was measured. In 5 cm/2 day submerged lot, all varieties having LEI positions at the 8th and 9th internodes could grow until the end of the experiment along with the increase of the water depth in both species. In these varieties, differences between species in almost growth characters were not observed. Among varieties having LEI positions from the 10th to 12th internodes,one African and one Asian variety failed to grow. No varieties having LEI position at the 13th internode could grow, because its average internode length was considerably short. Among varieties with LEI positions from the 8th to 11th internodes in 10 cm/2 day-submerged lot, 4 African varieties and one Asian variety did not grow. All varieties with LEI positions from the 12th to 14th internodes could not grow. From these results, it was suggested that under slow rising water conditions, internode elongation ability of both African and Asian floating rices was almost the same. Under rapid rising water conditions, however, internode elongation in the former was slightly inferior to that in the latter