Development of high yielding rice cultivars ‘Yamadawara’, ‘Emidawara’ and ‘Toyomeki’

Abstract

The new rice cultivars ‘Yamadawara’, ‘Emidawara’, and ‘Toyomeki’, officially registered by the Ministry of Agriculture, Forestry and Fisheries in 2014, 2022, and 2017, respectively, have been introduced to exploit the high-yielding ability of ‘Mizuhochikara’, a Japonica-Indica intermediate cultivar. ‘Yamadawara’ and ‘Emidawara’ are suitable for cultivation in the Kanto and Hokuriku regions as well as southern and western areas, whereas ‘Toyomeki’ can be cultivated in these areas as well as flat areas in southern Tohoku. The ripening period of ‘Emidawara’ is shorter than that of ‘Yamadawara’. All three cultivars have high lodging tolerance, and high yields can be obtained by high-fertilizer cultivation. Brown rice yields exceed 70 kg/a when transplanted early and are around 60 kg/a even when transplanted late. These yields are clearly higher than those of common staple food cultivars. The grain quality of ‘Yamadawara’ is inferior to that of ‘Asanohikari’, while that of ‘Emidawara’ is roughly equivalent to that of ‘Asanohikari’. The grain quality of ‘Toyomeki’ is inferior to that of ‘Koshihikari’. In terms of the physical properties of the cooked rice, all three cultivars are harder and less sticky than ‘Koshihikari’. Therefore, these cultivars can meet the demands of food service providers, being less sticky and suitable for cooking on factory lines, or for preparing pilaf or fried rice.