Growth and yield of modern deepwater rice: Comparisons with modern irrigated rice uri icon

abstract

  • Deepwater rice (DWR) is grown in flood-prone areas at water depths of 50 to 100 cm or more. Growth and yield of two modern DWR cultivars grown at a water depth of 80 cm were compared with high-yielding irrigated rice grown at 10 cm water depth during the wet season. Plant types of DWR which differed in tillering characteristics were produced by growing plants at different densities, and these were compared with irrigated rice cultivars to try and identify ideal plant types for DWR, Yield was higher in DWR plants (cv. HTA 60) with large numbers of mainstems per unit area and no nodal tillers. HTA 60 with many mainstems yielded more than 5 t ha(-1) during the wet season, similar to the yield of irrigated rice (cv. IR 72) grown under the same nutrient inputs. Yield of DWR planted at different densities was positively correlated with LAI at flowering (r(2) = 0.87), total dry matter at harvest (r(2) = 0.82), number of spikelets m(-2) (r(2) = 0.90) and number of mainstems m(-2) (r(2) = 0.76). While nodal tillering ability is an important trait for DWR in the event of stem reduction due to damage, DWR crops with a large portion of nodal tillers always had smaller LAI and lower yields than crops with no nodal tillers, In experiments where there was no stem damage and differences in LAI were accounted for, nodal tillers had no effect on yield as indicated by (i) the same yield/LAI in one field experiment and (ii) the same yields when plants with different portions of nodal tillers were grouped into canopies at flowering al either small or large LAI (LAI = 3 or 6). Ideal DWR plant canopies shown here have high densities and large LAI, and this is associated with plants that have a large portion of mainstems or primary tillers and no nodal tillers. Results are compared with other research where productivity of DWR and irrigated rice are grown in the field.

publication date

  • 1996
  • 1996