Elucidation of the growth characteristics of cultivar "Fusanomai" for the production of high-quality rice [Oryza sativa] for sake making

We investigated growth factors of rice that affect properties of rice for Sake making in cv. "Fusanomai" suitable for Sake brewing for the stable production of high-quality brown rice for Sake making 1. Factors that are thought to significantly affect properties of rice for Sake making, namely, 1000 grain weight of brown rice, the rate of white core, the rate of broken rice, water absorption for 20 minutes, water absorption of steamed rice, digestibility and crude protein content, fluctuated according to years and paddy fields. It was suggested that 1000 grain weight of brown rice, the rate of white core and crude protein content were significantly affected by the growth of rice. 2. Along with the increase of 1000 grain weight of brown rice, the rate of white core increased, and on the other hand, crude protein content decreased. Thus, it was concluded that 1000 grain weight of brown rice is an important factor when examining the relation between the growth of rice and properties of rice for Sake making. It was confirmed that 25.5 to 26.0 g was proper as the target 1000 grain weight of brown rice of cv. "Fusanomai" for the production of high quality brown rice for Sake making. 3. To ensure 1000 grain weight of brown rice of from 25.5 g to 26.0 g, from which high-quality brown rice for Sake making can be obtained, and the target yield of from 54.0 kg/a to 60.0 kg/a, the proper number of spikelet per square meters was from 25000 to 28000. It was considered that from 350 to 400 was proper for the target number of panicle per square meters to obtain this number of spikelet per square meters. 4. It was revealed that since the fluctuation range of the number of spikelet per panicle is narrow as varietal characteristics of cv. "Fusanomai", the increase of the number of panicle per square meters showed the tendency to cause the increase of the number of spikelet per square meters. In case the number of spikelet per square meters is too many, properties of rice for Sake making become worse by the decrease of 1000 grain weight of brown rice and of the rate of white core. Therefore, it was indicated that it's important in the management of cultivation to avoid the excess of the number of panicle per square meters.