Effects of Heavy Nitrogen Fertilization and Direct Seeding on the Yield and Grain Quality of the Rice Varieties Bred at the Tohoku Agricultural Research Center

Abstract

Three rice varieties, “Chihominori”, “Moeminori” and “Eminoaki” for ready-made meals and restaurants bred by Tohoku Agricultural Research Center were evaluated, using the data of the performance test for breeding obtained during a 5-year period. Heavy fertilization increased the number of panicles per area and the number of spikelets per panicle, resulting in higher grain yield and similar grain quality in appearance (AGQ), compared with normal fertilization. Direct seeding increased the number of panicles per area but decreased the grain yield and indicated similar or slightly superior AGQ, compared with transplanting. The early heading variety“Chihominori” showed a significantly higher grain yield and similar AGQ in heavy fertilization and direct seeding, compared with “Akitakomachi”. The intermediate heading variety “Moeminori” showed a significantly higher grain yield but inferior AGQ. The intermediate heading variety “Eminoaki” showed a slightly higher grain yield and superior AGQ, in high fertilization transplanting and high fertilization direct seeding, compared with “Hitomebore”. These results indicate that the three varieties are suitable for rice production with high yield, low cost and less labor for ready-made meals and restaurants. The results of this study suggested that the larger number of spikelets per panicle and slightly larger thousand grain weight are important in order to breed high yield varieties for ready-made meals and restaurants.