Abstract
The black-kerneled glutinous rice cultivar ‘Shiho’ was recently released in Niigata Prefecture, but the relationships among yield, polyphenol content and characteristics for rice cake processing have not been discussed precisely. We carried out the cultivation experiment under different conditions at several locations in Niigata Prefecture in 2006 and 2007, and examined various agronomic characters and grain properties of ‘Shiho’. Higher yield of ‘Shiho’ was attained by increasing the number of panicles per unit area by heavy manuring and the higher temperature during the ripening period. The higher temperature during the ripening period also resulted in the superior characteristics for rice cake processing, however lower content of polyphenol. Thus, it is difficult to find an appropriate cultivation method for satisfying simultaneously both yield and grain characteristics of ‘Shiho’ in higher order. It should be announced previously to rice farmers and the rice cake processed food company that ‘Shiho’ with higher polyphenol content could result in lower yield and inferior characteristics for rice cake processing. It may be important to develop of products characterized by keeping softness for a long period. ‘Shiho’ cultivated in different areas in Niigata prefecture showed marked differences in agronomic traits, ingredient of kernel and characteristics for rice cake processing, and damage by various diseases and pests. The cultivation methods need to be improved for various climatic conditions and farming systems in the mountainous region.
