Dry Matter Production, Yield and Grain Quality of Hybrid Rice Variety ‘Hybrid Togo 3’ under Low-Nitrogen Conditions

Abstract

For achieving high yield and grain quality under low nitrogen conditions in rice cultivation, dry matter production, yield and grain quality of the hybrid variety Hybrid Togo 3 (known for its superior palatability), the indica-type variety Oonari, and the Japanese-type variety Nipponbare were compared under high- and low-nitrogen (N) conditions in 2023 and under early- and late-type N applications of low-N conditions in 2024. Varieties that showed high yield under high-N conditions also showed high yield under low-N conditions. Although total dry matter weight did not differ among varieties, panicle weight was significantly heavier in Oonari and Tougou 3 than in Nipponbare at 20 and 40 days after heading. Rough brown rice yield was in the order of Oonari ≥ Togo 3 > Nipponbare. However, Oonari produced a considerable amount of immature brown rice. As a result, the brown rice yield was in the order of Togo 3 ≥ Oonari > Nipponbare. The proportion of perfect grains was significantly higher in Togo 3 than in Oonari. Under low-N conditions, the brown rice yield was slightly higher and the proportion of perfect was significantly higher under the late-type than the early-type N application. These results suggest that hybrid Togo 3 is optimal and the late-type N application is promising for obtaining both high yield and grain quality under low-N conditions.