Relationships between elongation and several growth parameters of floating rice under deep water condition
1989
Uchida, N. (Kobe Univ. (Japan)) | Azuma, T. | Yasuda, T. | Yamaguchi, T.
Raising the water level treatment was imposed at a rate of 4 cm per day on 14 floating rice varieties and on 3 non-floating rice varieties. This was done 20 days after the plant age of the rice varieties reached about 8.5 in leaf number on the main culm. The length of each plant part, the leaf area and the plant dry weight were measured at the start (T-0) on the 12th day (T-1) and on the 20th day (T-2). The relationship between the length or growth rate of each plant part and the growth parameters was investigated during the period I (T-0 to T-1) and II (T-1 to T-2). 1. The plant age in leaf number on the main culm increased by two to three in all varieties and the number of stems decreased in 14 varieties during the treatment period. The plant length and the length from the base of the main culm to the uppermost collar increased in all varieties. The position of the lowest elongated internode varied greatly among the varieties and the total internode length was greater in varieties in which internodal elongation had already occurred at the start of the treatment. All non-floating rice varieties elongated their internode at T-2 when floral differentiation did not occur. Great differences existed in the leaf area and the dry weight per plant among the varieties, especially in the leaf area above the water surface. 2. Change in RGR between period I and II varied among the varieties, with the result that RGR increased in 9 varieties and decreased in 8 varieties. NAR, RLGR, GR and A increased in most varieties between period I and II, whereas LAR decreased in all varieties. RLGR varied most among the varieties and LAR had relatively small variation
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