Abstract
Following the previous paper in which the number of shoot units with or without crown roots were studied in relation to the characters of the top of rice plant, several investigations were conducted in order to clarify the relation of the number of shoot units without crown roots to absorption of nitrogen and water in the ripening stage. Greater absorption of nitrogen and water, especially the latter, occurred in the rice plants which had lesser number of shoot units without crown roots and which were caused by moulding up the lower part of stems or by GA treatment in the later growth stage. Compared with cultivar Toyonishiki, similar situation was found in cultivar Ishikari whose number of shoot units without crown roots was less numerous. From these results, it is indicated that the number of shoot units without crown roots has intimate relation to absorption of nutrient and water in the ripening stage of rice plant and is considered that cultivar whose number of leaves on the main stem is numerous has disadvantage to keep the activity of top and root in the ripening stage high, because it has more numerous shoot units without crown roots than that having less number of leaves on the main stem.
