Expectations rise in Japan for Niigata's new 'Natsuhime' heat-tolerant rice

Niigata Prefecture in Japan has unveiled a new rice variety named Natsuhime, also known as the "summer princess." This rice variety made its debut this summer and is notable for its exceptionally early maturation, which allows for harvests starting in mid-August, earlier than other rice types. The Natsuhime rice is also praised for its impressive heat tolerance, making it a strong candidate to become a new "princess" in Niigata's rice lineup alongside other noteworthy varieties like Koshihikari and Shinnosuke.

Developed by the Niigata Agricultural Research Institute Crop Research Center, Natsuhime was crossbred in 2009 and went through approximately 15 years of development before its release. The rice's development prioritized both heat tolerance and flavor. The grains are large, with a lighter taste compared to Koshihikari, but its sweetness intensifies the more one chews. This year, around 400 hectares (approximately 988 acres) of Natsuhime were planted in the prefecture, with an anticipated yield of over 2,000 metric tons.

Natsuhime began to appear in supermarkets and other retailers in late August, priced at about 3,000 yen (approximately $19) per five kilograms. Niigata Gov. Hideyo Hanazumi has expressed enthusiasm about the variety's strong start. The high proportion of heat damage in rice production has driven breeding efforts in the region. In 1994, following a severe cold-weather event, the top-grade classification of Niigata-grown Koshihikari dropped to 64%.

To counteract the rising threat of heat damage due to global warming, the research center established an experimental field in 1997 to cultivate heat-tolerant varieties.

Since then, several heat-tolerant rice varieties have emerged, including Koshiibuki in 2000, Yukinkomai in 2006, and Shinnosuke in 2017. However, the heat tolerance of these varieties has been challenged by intensifying summer heat. In 2023, the proportion of top-grade Koshihikari rice dropped to a mere 4%, and in 2025, all Hazuki Minori rice submitted for grading was classified as second class.

The name Natsuhime was inspired by the image of rice plants growing gracefully through intense summer heat and sunlight before turning a golden color. The variety also offers several advantages for farmers, such as being less prone to lodging and having an earlier harvest period, which enables farmers to stagger harvest times from other rice varieties.

Furthermore, Natsuhime shows promise for cultivation using direct seeding in dry paddies, a method that could help capture demand in Japan's early-season rice market, traditionally strong in regions like Kyushu and Kanto.

The prefectural government is actively promoting Natsuhime through various channels, including videos, commercials featuring the Nihon Bunri High School's wind orchestra club, and special dishes offered by restaurants and traditional inns both within and outside the prefecture. The prefectural official expressed the hope that people will appreciate the aroma and flavor of freshly harvested Natsuhime at the earliest opportunity.