Hokkaido eyed as potential cultivation area for sweet potatoes

The Yomiuri Shimbun

November 10, 2021

Efforts are underway to make Hokkaido, the main potato producing region in Japan, a growing area for sweet potatoes as well.

Due to rising temperatures in recent years, it may be possible for Hokkaido to also cultivate sweet potatoes, which are generally grown in warmer climates. Demand for sweet potatoes is on the rise, thanks partly to expanding exports to Southeast Asian countries, where there is something of a boom for Japanese-style baked sweet potatoes.

Kyushu and other top production areas in Japan have had their crops damaged by disease, leading both the public and the private sector to look to Hokkaido for a stable supply.

On Oct. 6, people from fruit and vegetable wholesale companies as well as seed and seedling companies gathered on farmland owned by agricultural corporation Vegetable Works Inc. in the village of Makkari at the foot of Mt. Yotei in Hokkaido.

They dug bright purple sweet potatoes out of the earth, which they had planted over about 50 ares of the farmland in June. Together they harvested about 15 tons of sweet potatoes.

“This is the first time for me to grow [sweet potatoes], and they’re pretty easy to cultivate. I’m sure they’ll become more common in Hokkaido,” said Shin Sasaki, 42, the representative director of Vegetable Works.

These sweet potatoes were to be exported to Hong Kong, Singapore and other overseas destinations. The Agriculture, Forestry and Fisheries Ministry is supporting the project through the Japan External Trade Organization.

According to the ministry, exports of domestically produced sweet potatoes in 2020 were valued at ¥2.06 billion, an increase of more than 10 times over a decade. For those involved in sweet potato production, however, this is not cause for unalloyed joy.

One reason why is foot rot, a fungal disease that prevents the growth of stems and other parts of sweet potatoes. Foot rot has been identified in Japan, mostly in southern Kyushu, since 2018, causing lower crop yields for certain varieties.

Moreover, since the nuclear disaster at the Fukushima No. 1 nuclear power plant in Fukushima Prefecture in 2011, farm products harvested near there have had to be tested for radioactive substances. This has been a burden for relevant companies in terms of both time and cost.

Ensuring a stable supply is essential to take advantage of the swelling demand, and how to expand growing areas will be key. Attention has therefore turned to Hokkaido, despite the almost complete absence of production there in the past.

During recent summers, temperatures in the prefecture have climbed over 30 C on an increasing number of days. Snow and frost have also come later, making the environment more suitable to growing sweet potatoes.

“Utilizing as much as possible the brand power of Hokkaido as a source of food, we want to turn the prefecture into a growing area [for sweet potatoes] and expand the market,” said Junichi Kano, 39, who works for Tokyo-based major fruit and vegetable wholesale company Tokyo Seika Co.

Tokyo Seika is leading the sweet potato project in Makkari.