Difference in the quality of glutinous rice [Oryza sativa] among years and areas, and the factors affecting the quality in Hokkaido in northern Japan
2009
Tanno, H.(Hokkaido. Central Agricultural Experiment Station, Naganuma (Japan)) | Kinoshita, M. | Satoh, T.
In 2000-2003, the quality of glutinous rice, variety Hakuchou-mochi, was examined in six areas using 1044 samples, and hardenability of the rice cake was also examined using 86 samples. Furthermore, the growth characteristics were examined to clarify the factors causing yearly and regional differences. The yearly change on the average of all areas was 5.7-42.3% in sterility, 270-514 kg/10 a in brown rice yield, 74.2-88.4% in whole-grain ratio (WGR), 21.8-26.3 in brown rice whiteness (BRW), 44.6-52.7 in polished rice whiteness (PRW), 8.4-9.8% in protein content (PC), and 100-244 g in hardenability. Regional variation was similar to yearly change in WGR and PC, but was smaller in BRW, PRW and hardenability. In the area with cool meteorology, however, sterility and yield loss were large in a cool weather year, and thus difference within area was large in WGR, BRW, PRW, and PC. The lower the sterility and the higher the WGR, the lower was the PC; and the lower the PC and the higher the air temperature during grain-filling (ATDG), the higher the BRW and PRW. Furthermore, the higher the ATDG, the higher the hardenability. Thus, hardenability in Hokkaido greatly varied with the year, but was lower than that in 'Koganemochi' in Niigata Prefecture and 'Hiyokumochi' in Saga Prefecture in 2003-2004. From the above, decrease in sterility, decrease in PC, and advancing heading date were important for stable production of high-quality rice. The cultivation area of high hardenability should be limited.
اظهر المزيد [+] اقل [-]