Rice successfully grown in Hawaii without flooding fields

An international team of researchers has successfully grown rice in Hawaii without the traditional practice of flooding fields, demonstrating the viability of a water-saving cultivation method. The new approach produced a high-quality crop about one month earlier than usual, offering a promising solution for improving the islands’ food security.

The study was conducted by researchers from the Tokyo University of Agriculture and Technology and the University of Hawaii at Mānoa. They tested two well-known Japanese short-grain rice varieties, Koshihikari and Hitomebore, on upland fields on the island of Kauai. This cultivation method requires significantly less water, reduces infrastructure costs, and makes it possible to utilize abandoned agricultural land.

Field trials achieved yields of around 4 t/ha, comparable to upland rice production in Japan. Due to Hawaii’s shorter daylight hours, the rice flowered earlier, reducing the overall growing period by approximately one month.

Despite the shorter growing season, grain quality exceeded that of the rice grown in Japan. The harvested rice had larger and more transparent grains, along with a significantly lower share of chalky kernels, which are typically caused by heat stress. Researchers attribute these results to favorable weather conditions during grain filling and more efficient accumulation of nutrients.

Scientists believe this technology could help Hawaii reduce its dependence on imported rice and support the development of a local rice brand. The findings may also provide a sustainable production model for other island nations and water-scarce regions adapting to climate-related agricultural challenges.

Tags: rice, USA